2.0 WEIR INTAKE STRUCTUREITEM 2.1 COFFERDAM2.1.1 GENERAL2.1.1.1 DESCRIPTIONTo ensure that all areas are free from the disturbance that the water will cause to the constructions, this item shall contain but not limited to the following works: a. Excavation required for the construction of the weirb. Disposal of the excavated materialc. Backfilling around the weir structure to the original ground level or as required by the plansd. Works to make sure that all areas are free from water at all times during construction such as pumping and dewateringe. Sheet piling (if necessary)f. Construction and removal of temporary structures such as cofferdam, pipes, canals and ditches.g. Diversion of existing waterwaysThe Contractor shall submit to the Engineer a comprehensive plan and construction methodology on how he proposes to achieve this task. This shall include all the materials, labor, equipment, tools, pumping units, etc.2.1.2EXECUTIONThe Contractor shall have an engineering documentation for every cofferdam installation activity and is accessible for review by the Engineer and installation personnel. It must also provide a means of being held firmly and securely against the hull in the event of a loss of differential pressure. All patches must be secured such that they cannot rotate or move out of alignment with the hull opening. 2.1.3MEASUREMENT/BASIS OF PAYMENTAccomplishment shall be expressed in percentage of all accepted work items accomplished included of the Bill of Quantities for the period covered.The accepted quantities measured and prescribed above shall be paid for at the unit price indicated in the Bill of Quantities. This payment shall constitute full payment of all work done related to care of water, materials, labor, equipment, tools and incidentals necessary to complete this prescribed work item.

ITEM 2.2CLEARING AND GRUBBING2.2.1GENERAL2.2.1.1DESCRIPTIONThe Work under this item includes providing all labor, materials, tools and equipment necessary for clearing, grubbing, removing and disposing of all vegetation and debris (including earthen materials incidentally removed with vegetation and debris), and removing structures and obstructions located within the limits shown on the plans or designated by the Engineer, except such objects as are designated to remain in place or are to be removed in accordance with other sections of these Specifications. The Work shall also include the preservation from injury or defacement of all vegetation and objects designated to remain2.2.2EXECUTION2.2.2.1CLEARINGClearing shall consist of removing shrubs, and brush and disposal of all debris including rubbish occurring within areas to be cleared. Stumps, roots, brush, and other vegetation in the areas to be cleared shall be cut off below the original ground surface.2.2.2.2HAND CLEARINGIn areas where Hand Clearing is indicated on the Plans or designated by the Engineer, no equipment on wheels shall be used. Care shall be taken to insure that the grass, moss cover, or the natural ground as indicated in the plan is not disturbed.2.2.2.3SELECTED TREE REMOVAL Trees designated by the Engineer, outside of the normal clearing and grubbing and/or hand clearing limits, shall be removed and disposed of in accordance with this item. Trees to be removed may be designated by the Engineer at any time during the performance of the contract, and may be subject to the conditions specified under Hand Clearing. Trees designated for selective removal shall be cut off within six inches of the ground.2.2.2.4REMOVE AND RELOCATE BUSH OR TREE Bushes or trees shown on the Plans for removal and relocation shall be removed and relocated as directed by the Engineer. Bushes and trees designated for removal and relocation shall be carefully removed with enough of the root wad kept intact to ensure the survival of the bush or tree in its new locations. Bushes and trees designated for removal and relocation that are damaged, or that do not survive as a result of the transplanting, shall be replaced by the Contractor at its expense. The relocated bush or tree shall be placed to original depth at a location as directed by the Engineer.2.2.2.5GRUBBINGGrubbing shall consist of removal and disposal of stumps, roots larger than seventy five (75) millimeters in diameter and matted roots from designated grubbing areas. Logs and other organic or metallic debris and abandoned concrete footings shall be removed.2.2.2.6STRIPPINGThose areas that will be disturbed by excavation, filling, access road development, or compaction by equipment will be soil stripped to a depth of one hundred fifty (150) meters taking into consideration all planned erosion and sediment control practices shall be in place and functioning properly prior to soil stripping.2.2.3PRODUCTS2.2.3.1STORAGE PILESTopsoil that is suitable for reuse shall be placed in storage piles convenient to areas that are to receive application of topsoil. Topsoil shall be kept separate from the other excavated materials and shall be free of roots, stones larger than five (5) centimeters and other undesirable materials that would interfere with the planting.2.2.4MEASUREMENT/BASIS OF PAYMENTThe area that is to be cleared and grubbed to be paid for will be the number of square meter measure on the ground or site of the weir acceptably cleared in conformity with the plans or as directed by the Engineer.The accepted quantities, measured as prescribed above shall be paid for at the contract unit price for each of the particular pay items listed and included in the Bill of Quantities. The payment shall constitute full compensation for the removal and disposal of cleared and grubbed materials including all labor, equipment tools and incidentals necessary to complete the work prescribed in this item.

ITEM 2.3EARTH EXCAVATION2.3.1 GENERALThe excavation will generally refer to open excavation of foundation wet or dry and in all sorts of soils.2.3.1.1 DESCRIPTIONThis item shall consist of the necessary excavation for foundations and other structures indicated in the Plans, in accordance to these specifications and in conformity with the lines, grades and dimensions shown in the Drawings as indicated and established by the Engineer. The Contractor shall be aware of obstructions such as pipes, conduits and cables in the areas to be excavated. The Contractor shall verify the existence and location of such obstructions before the start of excavation. All excavated materials shall be disposed properly and deposited at locations indicated by the Engineer. 2.3.1.2NATURE of EXCAVATION:2.3.1.2.1 Unclassified Excavation Unclassified excavation shall consist of the excavation and disposal of all materials regardless of its nature, or not classified and included in the Bill of Quantities under other pay items.2.3.1.2.2Common Excavation Common excavation are those not included in the Bill of Quantities under Rock Excavation or other pay items.2.3.1.2.3Muck Excavation Muck Excavation shall consist of the removal and disposal of deposits of saturated of unsaturated mixtures of soils and organic matter not suitable for foundation materials regardless of moisture content.2.3.2EXECUTIONBefore commencement of excavation, spot levels on an approved grid covering the entire plot shall be taken by the Contractor in consultation with the Engineer and a proper record of these levels shall be kept jointly signed by the Contractor and the Engineer. A block level plan showing all ground levels of the plot shall be prepared by Contractor and shall also be jointly signed by the Contractor and the Engineer.Excavation shall include removal of all materials of whatever nature at all depths and whether wet or dry necessary for the construction of foundation exactly in accordance with lines, levels, grades and curves shown in the Plans or as directed by the Engineer. The bottoms of excavation shall be leveled both longitudinal and transversely or sloped as directed by the Engineer.Should the contractor excavate to a greater depth or width than shown on the Plans or as directed by the Engineer, he shall at his own expense fill the extra depth or width in cement concrete in proportion as to be directed by the Engineer. The Contractor shall report to the Engineer when the excavations are ready to receive concrete. No concrete shall be placed in foundations until the Contractor has obtained the Engineers approval. In case, the excavation is done through different types of soil and if different rates are applicable as per provision in the Bill of Quantities, the Contractor must get the dimensions of the strata agreed by the Engineer for payment. If no specific provisions is made in the Bill of Quantities it will be presumed that excavation shall be in all types of soil and the contractor's rate hall cover for the same.When there is evidence of discrepancy between the actual elevations and those shown in the plans, a pre-construction survey shall be conducted by the Contractor under the control of the Engineer to serve as the basis for the computation of the actual volume of excavated materials. All excavation shall be finished to a reasonably smooth and even surface. Excavation operation shall be carried out with outmost care ensuring that foundations below existing parts of structure shall not be disturbed. If instructed by the Engineer all foundation pits, and similar excavations shall be strongly fenced and marked with red lights at night to avoid accidents. Adequate protective measure shall be taken to make sure that the excavation does not affect or damage adjoining structures. All measures required for the safety of excavations, the people working in and around the foundation trenches, property and the people in the vicinity shall be taken by the Contractor at his own cost. He shall be entirely responsible for any injury and damage to property caused by his negligence or accident due to his constructional operations, storage of materials etc. Should there be disturbance of foundations below existing structures same shall be repaired and restored in a manner acceptable to the Engineer at no additional cost or compensation.2.3.2.1SHORINGThe sides of the excavations should be timbered or supported in such a way as is necessary to secure these from falling in, and the shoring shall be maintained in position as long as necessary. The Contractor shall be responsible for the proper design of the shoring to be approved by the Engineer to hold the sides of the excavation in position and ensure safety of persons and properties. The shoring shall be removed as directed after the items for which it is required are completed. Unless otherwise mentioned in the Bill of Quantities no extra payment will be made for shoring.2.3.2.2STACKING OF EXCAVATED MATERIALSMaterials suitable and useful for back filling, plinth filling or levelling of the plot or other use shall be stacked in convenient places but not in such a way as to obstruct free movement of men, animals and vehicles or encroach on the area required for constructional purposes.2.3.2.3BACKFILLINGAll shoring and form work shall be removed after their necessity ceases and trash of any sorts shall be cleaned out from the excavation. All space between foundation masonry or concrete and sides of excavation shall be refilled to the original surface with approved excavated materials in layers fifteen (15) centimeter in thickness watered and rammed. The filling shall be done after concrete or masonry is fully set and done in such a way as not to cause undue thrust on any part of the structure. Where suitable excavated materials is to be used for refilling it shall be brought from the place where it is temporarily stacked and used in refilling.No excavation of foundations shall be filled in or covered up until all measurements of excavations, masonry concrete and other works below ground level are jointly recorded. Black cotton soil shall not be used for back filling or in plinth filling.2.3.2.4DEWATERINGExcavation shall include bailing or pumping out water which may accumulate in the excavation during the progress of work either from seepage, springs, rain or any other cause and diverting surface flow if any by bunds or other means. Pumping out of water shall be done in such approved manner as to preclude the possibility of any damage to the foundation trench concrete or masonry or any adjacent structure. When water is met in foundation trenches or in tank excavations, pumping out water shall be carried out from auxiliary pit of adequate size dug slightly outside the excavations. The depth of auxiliary pit shall be more than the working foundation trench levels. The auxiliary pit shall be refilled with approved excavated materials after the dewatering is over. The excavation shall be kept free from water:a. during inspection and measurementb. When concrete / masonry works are in progress and till they come above the natural water level and c. Till the Engineer consider that the concrete/mortar is sufficiently set2.3.2.5SURPLUS EXCAVATED MATERIALSAll excavated materials certified as surplus and not useful shall be removed by the Contractor from the site in an approved manner with the approval of the Local Authority as required to his own dump and shall be paid as a separate item as in the Bill of Quantities. No extra claim on any account will be paid. The items of removal of surplus excavated materials shall only be undertaken by the Contractor when specific instruction in this regard has been obtained from the Engineer. The Contractor must also secure the approval of the Engineer regarding the quantity of surplus materials to be removed prior to commencement of this item of work.2.3.3MEASUREMENT/BASIS OF PAYMENTThe volume of excavation to be paid for will be the number of cubic meter measure in the original position of material acceptably excavated in conformity with the plans or as directed by the Engineer.The accepted quantities, measured as prescribed above shall be paid for the contract unit price for each of the particular pay items listed and included in the Bill of Quantities. The payment shall constitute full compensation for the removal and disposal of excavated materials including all labor, equipment tools and incidentals necessary to complete the work prescribed in this item.

ITEM 2.4ROCK EXCAVATION2.4.1GENERAL2.4.1.1DESCRIPTIONThis item shall consist of the necessary rock excavation for foundations and other structures indicated in the Plans, in accordance to these specifications and in conformity with the lines, grades and dimensions shown in the plans of as indicated and established by the Engineer. The Contractor shall be aware of obstructions such as pipes, conduits and cables in the areas to be excavated. The Contractor shall verify the existence and location of such obstructions before the start of excavation. All excavated materials shall be disposed properly and deposited at locations indicated by the Engineer.2.4.1.2Nature of Excavation:Rock excavation shall consist of igneous, sedimentary and metamorphic rock which cannot be excavated without blasting or the use of rippers, and all boulders or other detached stones each having a volume of 1 cubic meter or more as determined by physical measurements or visually by the Engineer.2.4.2 EXECUTIONBefore commencement of excavation spot levels on an approved grid covering the entire plot shall be taken by the Contractor in consultation with the Engineer and a proper record of these levels shall be kept jointly signed by the Contractor and the Engineer. A block level plan showing all ground levels of the plot shall be prepared by Contractor and shall also be jointly signed by the Contractor and the Engineer.When there is evidence of discrepancy between the actual elevations and those shown in the plans, a pre-construction survey shall be conducted by the Contractor under the control of the Engineer to serve as the basis for the computation of the actual volume of excavated materials. All excavation shall be finished to a reasonably smooth and even surface. Excavation operation shall be carried out with outmost care ensuring that foundations below existing parts of structure shall not be disturbed. If instructed by the Engineer all foundation pits, and similar excavations shall be strongly fenced and marked with red lights at night to avoid accidents. Adequate protective measure shall be taken to make sure that the excavation does not affect or damage adjoining structures. All measures required for the safety of excavations, the people working in & around the foundation trenches, property and the people in the vicinity shall be taken by the Contractor at his own cost. He shall be entirely responsible for any injury and damage to property caused by his negligence or accident due to his constructional operations, storage of materials etc. Should there be disturbance of foundations below existing structures same shall be repaired and restored in a manner acceptable to the Engineer at no additional cost or compensation.2.4.2.1 BLASTINGThe transportation, handling, storage, and use of dynamite and other explosives shall be directed and supervised by a personnel of proven experience and ability who is authorized and qualified to conduct blasting operations.Blasting shall be done in a manner as to prevent damage to the work or unnecessary fracturing of the underlying rock materials and shall conform to any special requirements specified. When specified, the contractor shall furnish the Engineer, in writing, a blasting plan before blasting operations begin.2.4.2.2USE OF EXCAVATED ROCK MATERIALSSuitable material from the specified excavations may be used in the construction of required rock fill. The suitability of material for specific purposes is determined by the Engineer.2.4.2.3DISPOSAL OF WASTE MATERIALSAll surplus or unsuitable excavated materials are designated as waste and shall be disposed of by the Contractor at sites of his own choosing away from the site of the work. The disposal shall be in an environmentally acceptable manner that does not violate local and national rules and regulations.2.4.2.4EXCAVATION LIMITSExcavations shall comply with Department Order No. 13 1998 otherwise known as Guidelines Governing Occupational Safety and Health in the Construction Industry. All excavations shall be completed and maintained in a safe and stable condition throughout the total construction phase. Structure and trench excavations shall be completed to the specified elevations and to the length and width required to safely install, adjust, and remove any forms, bracing, or supports necessary for the installation of the work. Excavations outside the lines and limits shown on the Plans or specified herein required to meet safety requirements shall be the responsibility of the Contractor in constructing and maintaining a safe and stable excavation.2.4.3MEASUREMENT/METHOD OF PAYMENTThe volume of excavation to be paid for will be the number of cubic meter measure in the original position of material acceptably excavated in conformity with the plans or as directed by the Engineer. The accepted quantities, measured as prescribed above shall be paid for the contract unit price for each of the particular pay items listed and included in the Bill of Quantities. The payment shall constitute full compensation for the removal and disposal of excavated materials including all labor, equipment tools and incidentals necessary to complete the work prescribed in this item.

ITEM 2.5HAULING OF MATERIALS2.5.1 GENERAL2.5.1.1 DESCRIPTIONThis item shall consist of hauling of materials specified in the Bill of Materials needed for the project. These are aggregates, cement, reinforcing bars, lumbers, formwork sand and other materials needed for the completion of the project.2.5.2EXECUTIONThe Contractor shall be responsible for monitoring truck weight regulations or the maximum allowable loads for various axle configurations on roadways outside the project limits and on roadways within the project limits open to general traffic. All hauling units delivering equipment or materials to the project shall be of legal weight loads and/or have appropriate hauling permits. The volume or amount of materials to be hauled to the project location of the project will conform to the amount of materials required for the project as specified on the Bill of Materials.2.5.3MEASUREMENT/BASIS OF PAYMENTThe Contractor will be paid as per accomplishment of the project.

ITEM 2.6ANCHORING 20MM RSB2.6.1GENERAL2.6.1.1DESCRIPTIONThis work shall consist of the installation of rock dowels at the locations and orientations designated in the Plans or by the Engineer. The Contractor shall select and construct the dowels and supply all materials, equipment, and labor to test and install the dowels. The Engineer will designate the orientation and minimum length of the dowel required.2.6.2SUBMITTALSNot less than two weeks prior to commencing the rock doweling, the Contractor shall submit in writing to the Engineer for approval:The Contractor shall provide written evidence that the foreman and drill operator have performed satisfactory work in similar capacities elsewhere. The drill operator assisted by the foreman shall have installed rock dowels as indicated in the Plan.The Contractor shall submit a detailed plan for the rock doweling to include:a.The proposed construction sequence and schedule.b.The proposed drilling method and equipment.c.The proposed drill hole diameter.d.The proposed cement grout mix designe.The proposed construction method for upwardly inclined anchors. f.The proposed corrosion protection for the rock dowel system.g.The calibration data for each load cell, test jack, pressure gauge and master pressure gauge to be used in the proof testing.h.The proposed stressing procedures and stressing equipment to proof test the dowels.Work shall not begin until the Engineer has approved the appropriate submittals in writing.2.6.3MATERIAL REQUIREMENTSAll rock dowels, including anchorage, bearing plates, couplers, corrosion protection, and other appurtenances, shall be products of a manufacturer regularly engaged in the manufacturing of materials for the construction of rock dowels. Dowels shall be fabricated from deformed steel bars in general compliance with DPWH Standard Specification. Anchor bar steel shall not be precut at the factory to lengths shown in the Plans, but rather be delivered in bulk lengths and field cut to the appropriate length. Anchor bar steel shall be provided with either fusion-bonded epoxy coating or hot dip galvanizing for corrosion protection. Epoxy coating shall be applied in accordance with ASTM A. Extreme care shall be taken in the handling of epoxy-coated bars to prevent coating damage and embrittlement. Field handling procedures for epoxy-coated bars shall be in general accordance with ASTM D 3963 including providing padding between contact points during storage and lifting and covering coated bars to minimize ultraviolet exposure. Hot dip galvanizing shall comply with ASTM A 15.Each rock dowel shall be fitted with a bearing plate and nut. The plate shall have a central hole large enough to fit easily over the dowel while maximizing the average bearing surface for the washer and the nut. Spherical seating of the nut is not required. Beveled washers shall be used to accommodate non-perpendicular installations.Cement grout shall be a proven, non-shrink material capable of permanently developing the bond and internal strength necessary for the required dowel capacity. The use of epoxy or polyester resin as bonding agents is not allowed. If requested by the Engineer, a sample of the cement grout shall be provided for testing.2.6.4EXECUTIONWork shall proceed according to the plan and schedule submitted by the Contractor prior to the commencement of the work.The Engineer shall specify the location, orientation, and minimum length of each rock dowel. The rock dowel shall be installed within five degrees of the specified angle. Unless otherwise specified, the angle of installation shall be perpendicular to the rock face and inclined slightly downward. If the axis of the rock dowel is not close to perpendicular to the rock face or within the angle provided by the beveled washer, or the rock beneath the bearing plate is not sound, a bearing pad approved by the Engineer shall be constructed at no additional cost, so that the rock dowel is not bent when tensioned. In all cases, at least three quarters of the bearing plate shall be in contact with the rock face.The dowels shall be handled and stored in such a manner as to avoid damage or corrosion of the coating and the steel. Damage to the dowel steel as a result of abrasion, cuts, nicks, welds, and weld splatter will be cause for rejection. The dowels shall be protected from dirt, rust, and harmful substances. If heavy corrosion or pitting is noted, the Engineer will reject the rock dowel. The entire length of the rock dowel shall be encapsulated in cement grout for a second level of corrosion protection. All exposed parts of the dowel, bearing plate and nut on the surface shall be painted with approved corrosion protection paint or epoxy patching compound.The use of hand drills for advancing the anchor hole is not allowed without written permission by the Engineer and demonstrated effectiveness by the Contractor.The drill hole shall be sized to provide a minimum of 50 millimeter of grout cover around the bar. The Contractor shall flush the drill hole of all drill cuttings and debris with compressed air prior to the installation of the rock dowel. Holes drilled for rock dowels in which dowel installation is considered by the Engineer to be impractical shall be re-drilled at the Contractors expense. The grout equipment shall produce a grout free of lumps and undispersed cement. The pump shall be equipped with a pressure gauge near the discharge end to monitor grout pressures. The grouting equipment shall be sized to enable the grout to be pumped in one continuous operation. The grout shall be injected from the lowest point of the drill hole. The quantity of the grout and the grout pressures shall be recorded.When the cement grout has reached final set, the Contractor shall install the bearing plate, washers and nut. The end of the completed rock dowel shall be trimmed to within 15 centimeters of the rock face.At the discretion of the Engineer, up to 5 percent, but not less than three rock dowels, of the installed rock dowels shall be proof tested. The Contractor shall conduct the proof test, and the Engineer will interpret the results. The rock dowel shall be tensioned to 11, 500 kilograms with a calibrated hollow-ram hydraulic jack using a bar extension and coupler attached to the rock dowel and held for 10 minutes. If no loss of load occurs over this time period, the rock dowel is acceptable. The Engineer may require additional proof of testing beyond the 5 percent maximum, if rock dowels fail the proof testing. All failed rock dowels shall be replaced with an additional rock dowel installed in a separate hole. No payment will be made for rock dowels that fail or for additional proof testing.2.6.5 MEASUREMENT/BASIS OF PAYMENTRock dowels will be measured per linear meter of rock dowel installed and accepted.The accepted quantity shall be paid for at the contract unit price and payment shall be full compensation for furnishing and placing all materials, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item.

ITEM 2.7STONE MASONRY2.7.1GENERAL2.7.1.1 DESCRIPTIONThis item shall consist of stone masonry in minor structures, in headwalls, for culverts, in retaining walls at the toes of slopes, and other places called for on the plans, constructed on the prepared foundation bed in accordance with this Specifications and in conformity with the lines, grades, sections, and dimensions shown in the plans or as ordered in writing by the Engineer. It shall include all management, labor, transportation, materials, tools, equipment and services required to manufacture, assemble, deliver, and install all items necessary for the proper execution and completion of said items of work.2.7.2MATERIAL REQUIREMENTS2.7.2.1 STONEThe stone shall be clean, hard and durable and shall be subjected to the Engineers approval. Adobe stone shall not be used unless otherwise specified.Sizes and Shaped. Unless other sizes are shown on the plans, stones shall have a thickness of not less than one and one half times their respective thickness, and lengths of not less than one and one half times their respective widths.Dressing. The stone shall be dressed to remove any thin or weak portions. Face stones shall be dressed to provide bed and joint lines that do not vary more than twenty (20) millimeters from corners of the stones in excess thirty (30) millimeters in radius. Bed surfaces of the face stones shall be approximately normal to the face of the stones for about eighty (80) millimeters and from this point may depart from a normal plane not to exceed fifty (50) millimeters in three hundred (300) millimeters.Finish for exposed Faces Face stones shall be pitched to line along the beds and joints. The maximum projection of rock faces beyond the pitch lines shall not be more than fifty (50) meters.2.7.2.2MORTARCement, fine aggregate, and water shall conform to the respective requirements for those materials as specified under structural concrete, except to the grading of the aggregate which shall all pass the two and thirty six hundredths (2.36) millimeters (No. 8) sieve, not less than fifteen (15) percent nor more than forty (40) percent shall pass the three tenths (0.3) millimeters (No. 50) sieve, and not more than ten (10) percent shall pass the fifteen hundredths (0.15) millimeters (No. 100) sieve.2.7.3EXECUTION2.7.3.1SELECTION AND PLACINGWhen the masonry is to be placed on a prepared foundation bed, the bed shall be firm and normal to, the face of the wall, and shall have been approved by the Engineer before any stone is placed.All stones shall be cleaned thoroughly and wetted immediately before being set and the bed which is to receive them shall be cleaned and moistened before the mortar spread. They shall be laid with their longest faces horizontal in full beds of mortar. The stones shall be handled as not jar or displace the stones already settled.Suitable equipment shall be provided for setting stones larger than those that can be handled by two men. The rolling or turning of stones on the walls will not be permitted. If a stone is loosened after the mortar has taken initial set, it shall be removed, the mortar cleaned off, and the stone is loosened after the mortar has taken initial set, it shall be removed, the mortar cleaned off, and the stone re laid with fresh mortar.2.7.3.2CURINGIf hot or dry weather, the masonry shall be satisfactory protected from the sun and shall be kept wet for a period of at least three days after completion.2.7.4MEASUREMENT/BASIS OF PAYMENTThe quantity to be paid for shall be the number of cubic meters of stone masonry complete in place and accepted. Projections extending beyond the faces of the walls shall not be included. In computing the quantity for payment, the dimension used shall be those shown on the plans or ordered in writing by the Engineer. No deductions shall be made for weep holes drain pipes or other openings of less than one square meter in area.The quantity of masonry, determined as provided, shall be paid for at the contract unit price per cubic meter for stone masonry, which price and payment shall be full compensation for furnishing and placing all materials, including mortar for masonry, for all necessary excavation, and for all labor, equipment, tools and incidentals necessary to complete the item.

ITEM 2.8REINFORCING BARS GRADE 402.8.1GENERAL2.8.1.1DESCRIPTIONThis item shall consist of furnishing, bending, fabricating and placing of steel reinforcement of the type, size, shape, and grade required in accordance with this specification and in conformity with the requirements shown on the plans or as directed by the Engineer.2.8.2SUBMITTALSA copy of list of all reinforcing steel and bending diagrams shall be furnished to the Engineer at the site of the work at least one week before the placing of reinforcing steel is begun. The Contractor shall be responsible for the accuracy of the lists and for furnishing and placing all reinforcing steel in accordance with the details shown on the plans.2.8.3MATERIAL REQUIREMENTSUnless otherwise designated on the plans, or herein, all reinforcing steel shall conform to the requirements of the following specifications:Table 2.8.3: STEEL SPECIFICATIONDeformed Billet - Steel Bars for Concrete ReinforcementASTM A 615

AASHTO M 31

Deformed Steel Wire for Concrete ReinforcementASTM A 496

AASHTO M 225

Welded Steel Wire Fabric for Concrete ReinforcementASTM A 185

AASHTO M 55

Cold - Drawn Steel Wire for Concrete ReinforcementASTM A 82

AASHTO M 32

Fabricated Steel Bar of Rod Mats for Concrete ReinforcementASTM A 184

AASHTO M 54

Welded Deformed Steel Wire Fabric of Concrete ReinforcementASTM A 497

AASHTO M 221

Plastic Coated Dowel BarsType A

AASHTO M 254

Loy Alloy Steel Deformed Bars for Concrete ReinforcementASTM A 206

Bar reinforcement for concrete structures, except No. 2 bars shall be deformed in accordance with AASHTO M 42, M31 and M53.Dowel and tie bars shall conform to the requirements of AASHTO M31 or AASHTO M42 except that rail steel should not be used for tie bars that are to be bent and re-straightened during construction. Tie bars shall be free from burring of other deformation restricting slippage in the concrete. A minimum of one half ( the length of each dowel bar shall be painted with one coat of approved lead of tar paint before delivery to the site of the work.The sleeves for dowel bars shall be metal of an approved design to cover fifty (50) millimeters (2 inches), plus or minus six and three tenths (6.3) millimeters of the dowel, with a closed end, and with suitable stop to hold the end of the sleeve at least twenty five (25) millimeters (1 inch) from the end of the dowel bar. Sleeves shall be of such design that they do not collapse during construction.Plastic coated dowel bar conforming to AASHTO M 254 may be used.2.8.4EXECUTION2.8.4.1ORDER LISTBefore materials are ordered, all order lists and bending diagrams shall be furnished by the Contractor, for approval of the Engineer. The approval or order lists and bending diagrams by the Engineer shall in no way relieve the Contractor of responsibility for the correctness of such lists and diagrams. Any expenses incident to the revisions of materials furnished with the plans shall be borne by the Contractor.Bar lists and bending diagrams for structures, which are included on the Plans, do not have to be furnished by Contractor. When bar lists and bending diagrams are included on the Plans, they are intended for estimating approximate quantities. Contractor shall verify the quantity, size, and shape of the bar reinforcement against those shown on the Plans and make any necessary corrections before ordering.2.8.4.2PROTECTION OF MATERIALSSteel reinforcement shall be stored above the surface of the ground upon platforms, skids, or other supports and shall be protected as far as practicable from mechanical injury and surface deterioration caused by exposure to conditions producing rust. When placed in the work reinforcement shall be free from dirt, detrimental rust, loose scale, paint, grease, oil or other foreign materials. Reinforcement shall be free from injuries effects such as cracks and laminations. Rust, surface scars, surface irregularities of mill scale will not be caused for rejection, provided the minimum dimensions are demonstrated.2.8.4.3BENDINGAll reinforcing bars shall be bent cold except as shown on the Plans or as permitted by the Engineer. Bars shall not be bent or straightened in a manner that will cause damage to the bars. Irregularities in the bars shall be caused for the rejection. Bars shall be bent around a circular pin having the following diameter (db) in relation to the diameter of the bar (d):Nominal Diameter (d), mmPin Diameter (db)

10 to 206d

25 - 288d

32 and greater10d

Bends and hooks in stirrups or ties may be bent to the diameter of the principal bar enclosed therein.2.8.4.4PLACING AND FASTENINGThe reinforcing bars shall be free from dirt, loose mill scale, paint, oil, loose rust, or other foreign substance.Steel reinforcement shall be accurately placed in the positions shown on the plans or as required by the Engineer and firmly held at all intersection during the placing and setting of concrete except where spacing is less than three hundred (300) millimeters in each direction, in which case, alternate intersections shall be tied. Ties shall be fastened on the inside. Distance from the forms shall be maintained by means of stays, blocks, ties, hangers, or other approved supports, so that it does not vary from the position indicated on the plans by more than six (6) millimeters. Blocks for holding reinforcement from contact with the forms shall be precast mortar blocks of approved shapes and dimensions. Layers of bars shall be separated by precast mortar blocks or by other equally suitable devices. The use of pebbles, pieces of broken stone or brick, metal pipe and wooden blocks shall not be permitted. Unless otherwise shown in the plans or required by the Engineer, the minimum distance between bars shall be forty (40) millimeters. Reinforcement in any member shall be placed and concrete begins. Concrete placed in violation of this provision may be rejected and removal may be required. If fabric reinforcement is shipped in rolls, it shall be straightened before being placed. Bundled bars shall be tied together at not more than one and eight tenths (1.8) meters interval.2.8.4.5SPLICING All reinforcement shall be furnished in the full lengths indicated on the plans. Splices of reinforcement shall be made only at locations shown on the Plans and provided by the steel schedule unless accepted by the Engineer. Splices shall be staggered as far as possible. Except otherwise indicated, splicing of reinforcement shall be in accordance with American Concrete Institute (ACI) 318M, except that the minimum separation shall not be less than forty (40) bar diameter. In cases where permission is granted to splice bars, other than those shown on the plans, the additional material required for the lap shall be furnished by Contractor at his own expense. All splices shall be full contact splices.Unless otherwise shown on the plans, bars shall be lapped a minimum distance of:Splice TypeGrade 40 Min. LapGrade 60 Min. LapBut not less than

Tension24 bar diam.36 bar diam.300 mm

Compression20 bar diam.24 bar diam.300 mm

In lapped splices, the bars shall be placed in contact and wired together. Lapped splices will not be permitted at locations where the concrete sections is sufficient to provide minimum clear distance of one and one third the maximum size of coarse aggregate between the splice and the nearest adjacent bar. Welding of reinforcing steel shall be done only if detailed on the plans or if authorized by the Engineer in writing. Spiral reinforcement shall be spliced by lapping at least one and a half turns or by butt welding unless otherwise shown on the plans.2.8.4.6WELDING OF SPLICESWhere shown on the plans or required by the provisions of this item, welded bar splices shall be used. All splices whether lap, weld, mechanical or coupler, shall develop the full strength of the bar. Information on mechanical splicing devices and couplers shall be submitted for approval prior to use.2.8.4.7LAPPING OF BAR MATSheets of mesh or bar mat reinforcement shall overlap each other sufficiently to maintain a uniform strength and shall be security fastened at the ends and edges. The overlap shall not be less than one mesh in width.2.8.5MEASUREMENT/BASIS OF PAYMENTThe quantity of reinforcing steel to be paid for will be the final quantity placed and accepted in the completed structure.No allowance will be made for tie-wires, separators, wire and other materials used in fastening the reinforcing steel in place. If bars are substituted upon the Contractors request and approved by the Engineer and as a result thereof more steel is used than specified shall be measured for payment.No measurement or payment will be made of splices added by the Contractor for his convenience. When there is no item for reinforcing steel in the Bill of Quantities, costs will be considered as incidental to the other item in the Bill of Quantities.The accepted quantity, measured as Bill of Quantities shall be paid for at the contract unit price for reinforcing steel which price and payment shall be full compensation for furnishing and placing all materials, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item.

ITEM 2.9 FORMS/ DEFORM WORKS2.9.1 GENERALThis item specifies the requirements for the design, construction and removal of formwork required to produce the finished concrete to the shape, lines and dimensions shown on the Plans.2.9.1.1DESCRIPTIONFormwork shall be meticulously checked of all recognized line and grade references so that the final structure is within the limits of the specified dimensional tolerances. They shall be designed to withstand the worst combination of self-weight, live load, rate of placement, height of drop, weight of moving equipment, together with all incidental dynamic effects caused by placing, vibrating and compacting the concrete. The Contractor shall verify that reinforcement is free of loose scale or rust and contaminants and shall be fabricated in accordance with fabrication herein specified and/or in the Plans. Reinforcement shall be checked of its allowable tolerances and splicing requirements, and shall be kept in its proper position during placement of concrete. The Contractor shall also check that all samples and certificates are submitted and approved. All items to be embedded in concrete shall be complete and in their proper position. Partially set concrete shall not be reworked and used. Vibrators shall not be used excessively and to transport concrete. Concrete flatwork shall be struck level and floated to disappearance of water sheen and shall be finished as specified. Concrete shall be cured as indicated and shall be protected from flowing water shock or excessive vibration during curing.2.9.2MATERIAL REQUIREMENTSThe type and condition of formwork sheeting and lining, and the ability of the formwork and its supports to withstand distortion caused by the placement and compaction of the concrete, and the standard of workmanship used in the formwork construction shall be such that the finished surfaces of the concrete will conform to the requirements of the specifications and Plans.Form lumber shall be stress graded or merchantable and shall be of non staining species and dressed on concrete forming side if to be used for exposedFormwork panels shall be supplied in the maximum practicable width and length to minimize the number of joints.Plywood panels shall be placed with the grain of the outer plies in the direction of the span.Form oil, or coating shall be non staining, compatible with subsequent finishing and bonding, and shall be effective in sealing wood from moisture.2.9.3EXECUTION2.9.3.1FORMWORK DESIGNFormwork shall be rigid, watertight, braced and tied together so as to maintain position and shape during all construction activities, and shall be constructed in such a way that it can be removed without damage to the concrete. Where formwork is to be re-used, the formwork design shall allow for the deterioration of materials through use and handling. Where formwork requires design, the Contractor shall submit to the Engineer for review of its detailed Plans and specifications of the proposed formwork not less than two weeks prior to the commencement of formwork construction.The formwork design shall be verified in accordance with the Contract to confirm that design satisfies the performance requirements of the formwork. Any amendment to the design shall be referred to the Engineer for review and final decision. The formwork Plans shall include all details of formwork, formwork joints, sealing procedures, ties, size and spacing of framing and details of any proprietary fittings or systems proposed to be used. Where vibration is to be applied externally, the design of formwork shall include details of external vibrators to ensure efficient compaction and to avoid surface blemishes.2.9.3.2FORM CONSTRUCTIONFormwork shall be constructed and shall be of sufficient stiffness to tolerate high frequency vibration and shall be of uniform stiffness to avoid causing varying vibration amplitudes over the formwork surfaces during compaction of the concrete. The constructed formwork shall maintain correct position and shape and achieve the specified dimensions, levels and geometry of the finished structural component. The use of wires or bolts extended to the surface of the concrete will not be permitted except where shown on the Plans. Any embedded ties shall remain embedded and shall terminate not less than the minimum clear cover specified on the Plans. All recesses shall be filled with a shrinkage compensating cementitious mortar. Errors in line or level of the formwork, or positioning and/or quantity of steel reinforcement shall be corrected prior to placing concrete. The Contractor will be responsible for any defects to the formwork, reinforcement, embedded components, or the formed concrete surface, which may become apparent during or after casting the concrete. Formwork shall not be placed in locations where steel reinforcement and other fixtures cannot be inspected, until such time that the evidence that the reinforcement and other fixtures conform to the requirements of the specifications and the Plans has been obtained and recorded by the Contractor.Fillets and chamfers shall be provided at re-entrant angles and corners. The interior surface of formwork shall be thoroughly cleaned out and treated with form oil or lubricant to prevent adhesion of the exposed concrete surface. The form oil or lubricant shall be of the non-staining type and shall not discolor the surface of the concrete. The oil or lubricant shall be applied uniformly in a thin film and any surplus removed prior the concrete placement. Reinforcement and other embedment shall not be soiled by the form oil or lubricant.Prior to commencement of the concreting operations all tie wire ends, wood chips and other debris shall be removed from the forms. Formwork shall be sufficiently tight at joints to prevent loss of slurry or mortar while the concrete is in its freshly placed state, consistent with the method of placement and compaction. Formwork shall also be mortar tight where holes are needed to facilitate projecting reinforcement or fixing devices.2.9.3.3REMOVAL OF FORMSFormwork shall be so constructed as to allow for its undisturbed dismantling and removal from the cast concrete without shock or damage. Shock or damage to the cast concrete shall also be prevented when removing formwork in the vicinity of projecting reinforcement or fixing devices. Side forms for beams, girders and walls three feet or less may be removed as directed by the Engineer earlier than otherwise specified.Time of removal of forms shall be as follows:a.Joints, beams and girder soffits.-Clear span less than three (3) meters seven (7) days-Clear span three (3) meters to six (6) meters fourteen (14) days-Clear span over six (6) meters twenty one (21) days.b.Slabs-Clear span six (6) meters seven (7) days-Clear span over six (6) meters fourteen (14) daysFormwork tolerance for cast in place concrete form plumb shall be as follows:a.Lines and surfaces of columns, piers, walls and arises one (1) centimeter per three and five hundredths (3.05) meters but not more than three (3) centimeters.b.Exposed corner columns, control joints, grooves and all conspicuous lines:-In any bay one half () centimeters-Distances up to six (6) meters one half () centimeters-Distances up to twelve (12) meters one (1) centimetersShoringAll trenches and other excavations shall be properly sheeted and braced, to furnish working conditions acceptable to the Engineer. Bracing shall be so arranged as not to place any strains on portions of completed work until the general construction has proceeded far enough to provide ample strength in the opinion of the Engineer.2.9.4MEASUREMENT/BASIS OF PAYMENTThe quantities measured as arranged above shall be paid for at the contract unit price of the pay item that is contained within the Bill of Quantities. Payment shall be the reimbursement for all materials, labor, equipment, tools, and incidentals necessary to complete the work prescribed in this item.

ITEM 2.10CONCRETING WORKS (3500 PSI)2.10.1GENERALConcrete shall be composed of Portland cement, fine aggregate, coarse aggregate, water and admixtures as specified for the work except as otherwise authorized in writing by the Engineer. Ready mix concrete shall be permitted, provided it can be placed within the time requirements specified and complies with all of the provisions hereinafter specified.2.10.1.1DESCRIPTIONThis item shall consist of furnishing, placing, and finishing concrete in concrete/ reinforced concrete structures in accordance with this specification and conforming to the lines, grades, and dimension shown on the plans.a.All reinforced concrete horizontal, vertical construction and expansion joints shall be provided with rubber water stop dumbbell type.b.Concrete for foundation, beams, columns, weir and desander shall have the strength of at least 3500 psi.c.Unless indicated all structures not exposed to water shall have a comprehensive strength of at least 3000 psi.2.10.2SUBMITTALSSamples of constituent materials and of concrete as placed shall be subjected to laboratory tests. The Contractor shall submit samples of materials as directed by the Engineer for his approval and all materials incorporated shall conform to the approved samples. The Contractor shall design the concrete mixes for all classes of concrete as will be define in this specification and submit his proposal together with the test results of the strength of all classes of the concrete mix design for the approval of the Engineer. The design of the concrete mixes and the concrete strength test shall be made in the field laboratory in the presence of the Engineer or his representative. The Contractor is responsible for all expenses incurred in this process. The use of ready-mixed concrete in any part of the work shall require the Engineers written approval. The Contractor shall satisfy the Engineers plan as to the sampling, trial mixing, testing and quality of concrete of various grades shall equally applied to ready-mixed concrete, which shall be made and delivered. Every additional facility including transport, which the Engineer or persons authorized by him may require for the supervision and inspection of batching, mixing and transporting to site of ready-mixed concrete shall be provided by the Contractor at no extra cost to the client. Prior to any major concreting as instructed by the Engineer, the Contractor shall submit a method statement furnishing all the relevant details including the plants he intends to use for the approval of the Engineer.

2.10.3MATERIAL REQUIREMENTS2.10.3.1PORTLAND CEMENTThe cement used for any particular mixed shall comply with the following cited specification for the type specified or permitted.TYPESPECIFICATION

Portland CementAASHTO M 85 (ASTM C 150)

Blended Hydraulic CementsAASHTO M 240 (ASTM 595)

Masonry CementAASHTO M 150 (ASTM C91)

When types IV and V (AASHTO M 85), P and PA (AASHTO M 150) cements are used, proper recognition shall be given to the effects of slower strength gain on concrete proportioning and construction practices. Types S and SA cements will be permitted only when blended with Portland cement in proportions approved only by the Engineer.Unless otherwise permitted by the Engineer, the product of only one mill of any brand and type of Portland cement shall be used on the project.The cement shall be in bags sealed with the manufacturers seal. The storage shall be maintain in a perfectly dry and well ventilated condition above ground level or as per instructions issued by the Engineer. Any cement which has been deteriorated or caked or which has been damaged due to any reason whatsoever shall not be used. Should the results of any laboratory tests show that any samples does not comply with the specified requirement, the whole consignment from which the sample was taken, shall be rejected and replaced with cement of satisfactory quality all shouldered by the Contractor. Any work carried out with the failed cement shall also be dismantled or corrective action taken by the Contractor as per instructions of the Engineer.2.10.3.2CONCRETE AGGREGATE2.10.3.2.1 FINE AGGREGATESSand or fine aggregate shall be comprise of natural sand, washed and sieved to remove particles larger than five (5) millimeters. It can be stone screenings or other inert materials with similar characteristics, or combination thereof, having hard, strong and durable particles approved by the Engineer. Fine aggregate from different sources of supply shall not be mixed or stored in the same pile nor used alternately in the same class of concrete without the approval of the Engineer.Fine aggregate shall not contain more than three (3) mass percent of material passing the seventy five hundredths (0.75) millimeters (No. 200) sieve by washing nor more than one (1) mass percent each of clay lumps or shale. The use of beach sand will not be allowed without the approval of the Engineer.If the fine aggregate is subjected to five (5) cycles of the sodium sulfate soundness test, the weighted loss shall not exceed ten (10) mass percent.The fine aggregate shall be free from damaging amounts of organic impurities. If subjected to colorimetric test for organic impurities and a color darker than the standard is produced, it shall be rejected. However, when tested for the effect of organic impurities of strength of mortar by AASHTO T71, the fine aggregate may be used if the relative strength at seven (7) and twenty eight (28) days is not less than ninety five (95) mass percent.Fine aggregate shall be capable of developing eighty (80) percent of the tensile strength of Ottawa sand. It shall be well graded from course to fine and not contain more than one (1) percent clay, coal, lignite and other deleterious substances such as shale, alkali, mica, coated grains, soft and flaky particles when tested according ASTM methods. All fine aggregate shall conform to the following requirements:TABLE 2.10.3.2.1:PERCENT PASSING OF DIFFERENT SIEVE SIZESieve SizePercent Passing

9.5 mm ( in )100

4.75 mm ( No. 4 )95 100

1.18 mm ( No. 16 )45 80

0.30 mm ( No. 50 )5 30

0.15 mm ( No. 100 )0 10

2.10.3.2.2COURSE AGGREGATESCoarse Aggregate shall be composed of hard, strong crystalline rock free form shale or other soft materials and free from any adherent coating or vegetable matter. It can be crushed stones, gravel, blast furnace slag, or other approved inert materials of similar characteristics, or combination thereof, having hard, strong, durable pieces and free from any adherent coatings.Coarse aggregates shall not contain more than one (1) mass percent of material passing the 0.075 mm (No. 200) sieve, not more than 0.25 mass percent of clay lumps, nor more than 3.5 mass percent of soft fragments.If the course aggregate is subjected to five (5) cycles of the sodium sulfate soundness test, the weighted loss shall not exceed 12 mass percent.It shall have a maximum mass percent of forty (40) when tested by AASHTO T 96. If slag is used, its density shall not be less than one thousand one hundred twenty (1120) kilograms per cubic meter or seventy (70) pounds per cubic foot. Only one grading specification shall be used and it shall conform to the following required grading for coarse aggregate.TABLE 2.10.3.2.2: GRADING FOR COARSE AGGREGATESIEVEDESIGNATIONMASSPERCENTPASSING

STANDARDmmALTERNATEU.S. StandardGRADINGAGRADINGBGRADINGC

75.03 in100--

63.02 in90 100 100100

50.02 in- 90 100 95 100

37.51 in25 60 35 75 -

25.01 in-0 15 35 70

19.0 in0 10 --

12.5 in0 5 0 5 10 30

4.75No. 4--0 5

2.10.3.2.3AGGREGATE TESTSTesting of aggregates is a way by which the properties of a material are routinely evaluated and compared with the appropriate specification requirements. Samples of the aggregates to be used shall be selected by the Engineer for tests at least thirty (30) days before the start of actual concreting operations. It shall be the responsibility of the Contractor to designate the sources of aggregates to give the Engineer ample time to obtain the necessary samples and submit them for testing.No aggregate shall be used until advice has been received that it has satisfactory passed all tests to the satisfaction of the Engineer, at which time written approval shall be given for its use.In stating requirements for most materials, reference has been made to AASHTO and ASTM Standard Specification for material. Those Specifications, in turn, include reference to the respective AASHTO and ASTM methods of sampling and testing. In such instances the following methods of sampling and testing will govern:TEST METHODSPECIFICATION

Amount of Material Finer than 0.075 mm Sieve in AggregateAASHTO T 11

Unit Weight of AggregateAASHTO T 19

Sieve Analysis of Fine and Course AggregatesAASHTO T 27

Resistance to Abrasion of Small Size Coarse Aggregate by Use of the Los Angeles MachineAASHTO T 96

Soundness of Aggregate by Use of Sodium Sulfate of Magnesium SulfateAASHTO T 104

2.10.3.2.4WATERWater to be used in concrete works such as mixing, curing, or other assigned application shall be sensibly clean and fresh. It shall be free from oil, acids, alkali, sewage, and organic or other deleterious matter. Water will be tested in accordance with and shall meet the requirements of water from DPWH Standard and Specification for Public Works and Highways. Drinking water may be used without test. Where the source of water is shallow, the intake shall be so enclosed as to exclude silt, mud, grass or other foreign materials.2.10.3.2.5METAL REINFORCEMENTReinforcement shall be detailed, fabricated, placed, and supported in place in accordance with the following specifications:Deformed and Plain Billet Steel(ASTM A 615)

Bars for Concrete ReinforcementAASHTO M 31

Deformed Bars Steel and PlainASTM A 616ASTM A 617

For reinforcing bars to be welded, the following ASTM specifications shall be accompanied by the requirements assuring satisfactory weldability.Bar and Rod Mats for Concrete ReinforcementASTM 187(ASTM A 82)

Cold Drawn Steel Wire for Concrete ReinforcementAASHTO M 32(ASTM A 185)

Welded Steel Wire Fabric for Concrete Reinforcement(ASTM A 185)AASHTO M 55

Except that the weld shear strength requirements of those specification shall be extended to include a wire differential up to and including six gauges.Reinforcement shall be secured in place with concrete or metal spacers. Metal spacers extending to the surface of the concrete or wooden supports shall not be used. Reinforcement shall be free from scale, rust, or coatings that will reduce the bond between reinforcement and concrete.2.10.3.2.6RUBBER SEALWater stop shall be used in all vertical, horizontal, construction and expansion joint as needed.2.10.3.2.7ADMIXTURESWhen required by the engineer, admixtures shall be approved quality. The Contractor shall furnish full details of the admixtures prior to use in works. The employment of admixtures for concrete mix shall be at the discretion of the Contractor and at no additional cost to the Employer. The amounts and types of additives used shall be as directed or approved by the Engineer and may be varied by him according to the location of the work or for other reasons.If air entraining admixture is used, it shall conform to ASTM C 260.If used, water reducing, water proofing and water reducing, retarding and accelerating admixtures shall conform to the requirements of ASTM C 494.2.10.3.3STORAGE OF MATERIALSImmediately upon arrival at the site, cement and aggregates shall be stored in storage designed for the purpose or in dry weather-tight and properly ventilated structures with floors raised in a reasonable height above ground level with adequate provision to prevent absorption of moisture. Aggregates shall be stored on clean hard bases that permit free drainage. Care must be taken so as to prevent foreign objects from mixing and cross contamination between materials will be prevented. All storage facilities shall be subject to approval by the Engineer and shall be such as to permit each access for inspection and identification.2.10.4EXECUTION2.10.4.1CONCRETE QUALITYThe quality and method and control of manufacture and transportation of all concrete work irrespective of mix, whether reinforced or otherwise, shall conform to the applicable portions of this specification. The Engineer shall have the right to inspect the source(s) of materials, the layout and operation of procurement and storage of materials, the concrete batching and mixing equipment, the quality control system. Such an inspection shall be arranged and Engineers approval obtained, prior to starting of concrete works.All plans submitted for approval of used for any structure in the project shall clearly show the specified strength of concrete, Fc, of the specified age for which it was designed.Concrete that will be exposed to sulfate containing of other chemically aggressive solutions shall be proportioned in accordance with Recommended Practice for Selecting Proportions for Concrete (ACI 613) and Recommended Practice for Selecting Proportions for Structural Lightweight Concrete (ACI 613A).2.10.4.2METHODS OF DETERMINING THE PROPORTIONS OF CONCRETEThe determination of the proportions of cement, aggregates, and water to attain the required strengths shall be made by one of the following methods, but lower water cement ratios may be required for conformance with the quality of concrete.a.Without Preliminary TestWhere preliminary test date the materials to be used in the concrete have not been obtained the water to cement ratio for a given strength of concrete shall not exceed the values shown on the following table. When strengths in excess of two hundred eighty one (281) kilograms per square centimeter or four thousand (4000) pounds per square inch are required of when light weight aggregates of admixtures (other than those exclusively for the purpose of entraining air) are used, the required water to cement ratio shall be determined in accordance with the next method to be mention.

TABLE 2.10.4.2:MAXIMUM PERMISSIBLE WATER TO CEMENT RATIO FOR DIFFERENT CONCRETES COMRESSIVE STRENGTHSPECIFIED COMPRESSIVE STRENGTH AT 28 DAYS, Fc(PSI)MAXIMUM PERMISSIBLE WATER CEMENT RATIO

Non air entrained concreteAir entrained concrete

U.S. gallon per 42.6 kilograms bag of cementAbsolute ratio by weightU.S. gallon per 42.6 kilograms bag of cementAbsolute ratio by weight

25007 0.6426 0.554

30006 0.5765 0.465

35005 0.5104 0.399

400050.44340.354

b.For combination of materials previously evaluated to be established by trial mixtures.Water to cement ratios for strength greater than that shown in the above table maybe used provided that the relationship between strength and water to cement ratio for the materials to be used has been previously established by reliable test data and the resulting concrete satisfies the requirements of concrete quality.Where previous data are not available, concrete trial mixtures having proportions and consistency suitable for the work shall be made using at least three different water to cement ratios (or cement content in the case of lightweight aggregates) which will produce a range of strengths encompassing those required for the work. For each water to cement ratio (or cement content) at least three specimens for each age to be tested shall be made, cured and tested for strength in accordance with ASTM C 39 and ASTM C 192.The strength test shall be made at seventh (7th), fourteenth (14th) and twenty eighth (28th) days at which the concrete is to receive load, as indicated on the plans. A curve shall be established showing the relationship between water to cement ratio (or cement content) and compressive strength. The maximum permissible water to cement ratio for the concrete to be used in the structure shall be that shown by the curve to produce an average strength to satisfy the requirements of the strength test of concrete provided that the water to cement ratio shall be no greater than that required by concrete quality when concrete that is to be subjected to the freezing temperatures shall have a water cement ratio not exceeding six (6) gallons per bag and it shall contain entrained air.Where different materials are to be used for different portions of the work, each combination shall be evaluated separately.2.10.4.3 CONCRETE PROPORTIONS AND CONSISTENCYThe Contractor shall design concrete proportion to produce concrete required strength. Notwithstanding the acceptance by the Engineer of any mix design and series of trial mixes, variations may be made to the proportions when considered necessary by the Engineer.The proportion of aggregate to cement for any concrete shall be such as to produce a mixture which will work readily into the corners and angles of the form and around reinforcement with the method of placing employed on the work, but without permitting the materials to segregate or excess free water to collect on the surface. The methods of measuring concrete materials shall be such that the proportion can be accurately checked at any time during the work.2.10.4.4SAMPLING AND TESTING OF STRUCTURAL CONCRETEThe Contractor shall provide the equipment necessary to determine the compacting factor of freshly mixed concrete at each place where concrete is being made and shall determine the compacting factor of the freshly mixed concrete. At least one (1) set of sample consisting of three (3) concrete cylinder test specimens, one hundred fifty (150) by three hundred (300) millimeter shall be taken from each class of concrete placed each day, and each serves to represent not more than seventy five (75) cubic meter of concrete.2.10.4.5CONSISTENCYConcrete shall have a consistency such that it will be workable in the required position. It shall be such that it will flow around reinforcing steel but individual particles of the coarse aggregate when isolated shall show a coating or mortar containing its proportionate amount of sand. The consistency of concrete shall be gauged by the ability of the equipment to properly place it and not by the difficulty of mixing water shall be determined by the Engineer and shall not be varied without his consent. Concrete as dry as it is practical to place with equipment specified shall be used.2.10.4.6STRENGTH TEST OF CONCRETEConcrete shall be subjected to compressive and flexural strength test as specified in ASTM C 31, Making and Curing Concrete Compressive and Flexural Strength Tests Specimens in the Field. Each class of concrete shall be represented by at least five (5) tests having an accumulation of ten (10) specimens. Two (2) specimens shall be made for each test at a given age, and not less than one (1) test shall be made for each one hundred fifteen (115) cubic meter of structural concrete, but there shall be at least one (1) test for each day concreting. The Engineer may require a reasonable number of additional tests during the progress of the work. Samples from which compression test specimens are molded shall be secured in accordance with ASTM C 172. Specimens made to check the adequacy of the proportions for strength of concrete or as a basis for acceptance of concrete shall be made and laboratory cured in accordance with ASTM C 31. Additional test specimens cured entirely under field conditions may be required by the Engineer to check the adequacy of curing and protection of the concrete.If it appears that the laboratory cured specimen will fail to conform to the requirements for strength, the Engineer shall have the right to order changes in the concrete mix sufficient to increase the strength to meet these requirements. The strengths of any specimen cured on the job are intended to indicate the adequacy of protection and curing of the concrete and may be used to determine as to when the forms may be stripped, shoring removed or the structure placed in service. In the opinion of the Engineer, the strength of the job cured specimen are excessively below those of the laboratory cured specimen, then the Contractor may be required to improve the procedures for protecting and curing concrete.The age for strength tests shall be twenty eight (28) days or, where specified, the earlier age at which the concrete is to receive its full load of maximum stress. Additional test may be made at earlier ages to obtain advance information on the adequacy of strength development where age strength relationships have been established for the materials and proportions used.To conform to the requirements of this item:a.For structures designed in accordance with working stress design method of this chapter, the average of any five consecutive strength tests of the laboratory cured specimens representing each class of concrete shall be equal to or greater than the specified strength, Fc and not more than twenty (20) percent of the strength test shall have values less than that specified.b.For structures designed in accordance with the ultimate strength design method of this chapter, and for pre stressed structures the average of any three consecutive strength test of the laboratory cured specified representing each class of concrete shall be equal to or greater than the specified strength, Fc and not more than ten (10) percent of the strength tests shall have values less than the specified strength.The Contractor shall provide for all costs in the making of such tests including allowing free access to the work for the selection of samples, providing moist storage facilities for specimen, affording protection of the specimen against injury or loss through his operations, and furnishing material and labor required for the purpose of taking and testing of samples. The Contractor shall make slump tests in the field and when instructed by the Engineer in the presence of the Engineer's representatives. The Engineer may request that dynamic testing or loading test to be executed when the results of the laboratory test are not satisfactory for completed works. The Contractor at his own cost shall carry out testing and inspection work.2.10.4.7BATCHINGWhen batches are hauled to the mixer, bulk cement shall be transported either in waterproof compartments or between the fine and course aggregates. When cement is placed in contact with moist aggregates, batches will be rejected unless mixed within one half () hours of such contact. Sacked cement may be transported on top of the aggregates.Batches shall be delivered to the mixer separate and intact. Each batch shall be dumped cleanly into the mixer without loss, and, when more than one batch is carried on the truck, without spilling of material from one batch into another.2.10.4.8MIXING AND DELIVERYMixing of concrete shall continue until there is a uniform distribution of material and the concrete is uniform in color and consistency. Concrete may be mixed at the site of construction, at a central point and truck mixing or by a combination of central point mixing and truck agitating. Mixing the delivery of concrete shall be in accordance with the appropriate requirements of AASHTO M 157 except as modified in the following paragraphs of this section, for truck mixing or a combination of central point and truck mixing or truck agitating.The mixer shall be operated at the drum speed as shown on the manufacturers name plate on the mixer. Any concrete mixed less than the specified time shall be discarded and disposed of by the Contractor at his own expenses.The timing device on the stationary mixers shall be equipped with a bell or any suitable warning device adjusted to give a clearly audible signal each time the lock is released.Mixes and weighs batches shall be maintained in first class condition throughout the time period and any mixer or plant which is faulty shall not be used. A mixer of any type shall be maintained in a clean serviceable condition and their accuracy periodically checked.If volumetric measurement is allowed, the weight proportions shall be converted to equivalent volumetric proportions. In such cases, suitable allowance shall be made for variations in the moisture condition of the aggregate.2.10.4.9 CONCRETE SURFACE FINISHES2.10.4.9.1 CURING CONCRETEAll freshly deposited concrete shall be protected from premature drying and excessively hot or cold temperatures, and mechanical injury and shall be maintained with minimal moisture loss at a relatively constant temperature for the period of time necessary for the hydration of the cement and proper hardening of the concrete. Curing of concrete in the field shall conform to the required standard of ASTM C31/C31 M, Standard Practice for Making and Curing Concrete Test Specimens in the Field.The Contractor shall protect all concrete work against injury from outside elements and defacement of any nature during construction operations. All concrete, particularly exposed surfaces shall be treated immediately after concreting or cement finishing is completed, and shall be provided with continuous moist curing for at least seven (7) days regardless of the ambient air temperature. Walls and vertical surfaces may be covered with continuously saturated burlap or by other approved means. Horizontal surfaces, slabs, and other items shall be inundated with pool of water to a depth of one and 2 tenths (1.2) centimeter and kept continuously wet with the use of sprinklers. Finished surfaces and slabs shall be protected from the direct rays of the sunlight to prevent shrinking and cracking.The curing method shall be one or more of the following:a. Water Method The concrete shall be kept continuously wet by the application of water for a minimum period of seven (7) days after the concrete has been placed.b.Curing Compound Surfaces exposed to the air may be cured by the application of an impervious membrane approved by the Engineer.c.Waterproof Membrane Method The exposed finished surfaces of concrete shall be sprayed with water, using a nozzle that so atomizes the flow that a mist and not a spray are formed until the concrete has set, after which a curing membrane of waterproof paper or plastic sheeting shall be placed.d.Forms-in-Place Method Formed surfaces of concrete may be cured by retaining the form in place. The forms shall remain in place for a minimum period of seven (7) days after the concrete has been placed, except that for members over fifty (50) centimeters in least dimension, the forms shall remain in place for a minimum period of five (5) days.e.Curing Cast-in-Site Concrete All newly placed concrete cast-in into the structures shall be cured by the water method, the forms- in-place method, or as permitted herein, by the curing compound method. f.Curing Pre-Cast Concrete Piles All newly placed concrete for pre-cast concrete piles, conventionally reinforced or pre-stressed shall be cured by the Water Method as described in subsection Curing Concrete, except that the concrete shall be kept under moisture for at least fourteen (14) days. All the option of the Contractor, steam curing maybe used in which case the steam curing provisions of DPWH SS subsection 407.3.8 (6) curing pre-cast concrete shall apply except that the concrete shall be kept wet for at least seven (7) days including the holding and steaming period. 2.10.4.9 ACCEPTANCE OF CONCRETE2.10.4.9.1 STRENGTH OF CONCRETEConcrete not meeting the requirements of this specification shall be considered potentially deficient and may be rejected. The strength of concrete shall be deemed acceptable if the average of three (3) consecutive strength test results is equal to or exceeds the specified strength and no individual test result falls below the specified strength by more than fifteen (15) percent. Three (3) cores shall be obtained from the affected area and cured and tested in accordance with AAASHTO T 24. Concrete in the area represented by the cores will be deemed acceptable if the average of cores is equal to or at least 85 percent and no sample core is less than seventy five (75) percent of the specified strength otherwise it shall be rejected.2.10.4.9.2SLUMPConcrete not within the slump limits as designated in this item at the point of placement may be rejected. When the concrete is tested and found to be out of specifications, the Contractor shall immediately adjust the mix to bring the mixture within the slump limits.2.10.5 MEASUREMENT/BASIS OF PAYMENTThe quality of concrete to be paid shall be the quality shown in the Bill of Quantity unless charges in design are made in which case the quality shown in the Bill of Quantity will be adjusted by the amount of the change for the purpose of payment. No deduction will be made for the volume occupied by pipes less than one hundred one (101) millimeters or four (4) inches in diameter or for reinforcing steel, anchors, weep holes or expansion materials.The accepted qualities of structural concrete completed in place will be paid for at the contract unit price for cubic meter as indicated in the Bill of Quantities.Pay Item and DescriptionUnit of MeasurementStructural ConcreteCubic MeterSuch prices and payment shall be full compensation for furnishing all materials, including metal water stops, joints, joint filers, weep holes, and rock backing and timber bumpers; for all form and false work; for mixing, placing, furnishing, and curing and concrete; and for all labor, materials, equipment, tools, and incidentals necessary to complete the item, except that reinforcing steel shall be paid for at the contract unit price per kilograms for reinforcing steel metal pipes and drains, metal conduits and ducts, and metal expansion angles shall be paid for as structural steel that when the proposal does not include an item for structural steel these miscellaneous metal parts shall be paid for as reinforcing steel.

ITEM 2.11 GATE LIFTING MECHANISM FABRICATION AND INSTALLATION2.11.1 GENERAL2.11.1.1 DESCRIPTIONThis item includes the supply, furnishing and installation of stainless steel intake and flushing gates.2.11.2 CONTRACTORS SCOPEThe Contractors scope for this work item shall be the following:a. The Contractor shall supply, install, test and commission a fully operational weir intake, desander intake, desander flushing, head ponds drain gates as reflected in the Plans are in accordance with the provisions of these Specifications or as instructed by the Engineer.b. The Contractor shall construct the framing of the Inlet Portal gate slots and other related steel works and concrete embedded works.2.11.3RELATED STANDARDIt is recommended that American Water Works Association (AWWA) C501 Specification be used as guidance for selection and fabrication of the weir intake, desander intake and desander flushing drain gates.2.11.4MATERIAL REQUIREMENTSThe gates shall be made of A36 steel. All materials shall be new and shall be meet the required ultimate strength, limit of elasticity, ductility, hardness, durability, suitability for the intended service and best engineering practice. All materials shall comply with the latest applicable standard of ASTM unless otherwise specified or approved by the Engineer.The lifting mechanism of the intake and flushing gates shall be supplied and installed by approved supplier.Gate lifting mechanism shall consist of a steelbodied and steelmounted gate with steel faced wedges and wedge blocks. Side wedges shall be adjustable. Top and bottom wedges shall withstand seating and unseating heads.Frames shall be circular or rectangular flanged frames to connect with wall thimbles and provide for openings of the shape and dimensions specified.Each extension stem shall be the same material and the same size as the stem of the gate it operates. Brackets and stem guides shall be made of steel and fully adjustable. The guide block shall be bushed where it contacts the extension stem.The gate should be capable of withstanding the seating, unseating, and operating heads. A seating head and an unseating head equal to the difference between the top of levee elevation and the closed gate elevation should be used in design. All components should be adequate to withstand all stresses encountered during installation or operation without breakage or deleterious deformation.Each gate should meet leakage requirements of the AWWA. AWWA specifications maintain that leakage under seating head should not exceed one tenths (0.1) gallons per minute per foot of perimeter. Under the design unseating heads, leakage should not exceed two tenths (0.2) gallons per minute per foot of perimeter. It is recommended that each gate be equipped with adjustable wedges. Wedges allow for gate adjustment and control of leakage. Wedges are typically used on both upstream and downstream sides of the gate and are also available for the top and bottom of the gate.All materials that develop defects during or after fabrication shall be rejected notwithstanding that they have previously passed specified tests and inspections, and met the applicable requirements stated herein.Gate seal shall be provided with rubber seals and are bolted on to the skin plate by means of a steel clamp plates, stainless steel bolts, nut and washers. The initial deflection of side and top rubber seals (J type) and the bottom seals (I type) is five (5) millimeters.The gate and all cast iron parts (not bearing or sliding contact) and stem guides shall be provided with a shop applied protective coating to consider a medium corrosive environment service. The paint system shall be in accordance with item regarding painting somewhere in this specification. The rising stem operator shall be composed of an actuator (drive motor and controls), a bevel gearbox, operator base and/or stanchion as may be required or as determined necessary by the operator manufacturer.The completely assembled gate and hoist shall be separately shop operated to insure proper assembly and operation. The gate shall be adjusted so that four thousandths (0.004) inch thick gauge will not be admitted at any point between frame and cover seating surfaces. All gates and equipment shall be inspected and approved by the Engineer prior to shipment.Gates and equipment shall be stored and installed in accordance with the installation manual furnished by the gate manufacturer. After installation, the completely assembled gate, stem, guides and lift shall be operated through one full cycle to demonstrate satisfactory operation. Such adjustments as necessary will be made until the Engineer approves operation. When required by the Engineer, the gate shall be subjected to leakage tests and pass the standard requirements for maximum leakage as specified in AWWA standards AWWA C 501.Joints shall be fabricated accurately for close fit. Weld exposed joints continuously unless otherwise indicated or approved. Dress exposed welds flush and smooth. All welds shall be according to the applicable provisions as stated herein.Form exposed connections with flush, smooth and hairline joints, shall use concealed fasteners wherever possible. Use Phillips flathead (countersunk) bolts or screws for exposed fasteners, unless otherwise shown or specified. Furnish flat washer under connections requiring raised bolt heads. Provide lock washer under nuts when through bolting occurs. Punch, reinforce, drill, and tap metal work as required to receive hardware and other appurtenant items.Unless otherwise specified or noted, items indicated to be galvanized shall receive a zinc coating by the hot dip process, after fabrication, complying with the following:a.ASTM A 123 for plain and fabricated material, and assembled products.b.ASTM A 153 for iron and steel hardware.2.11.4EXECUTION2.11.4.1 INSTALLATION OF EMBEDDED ITEMSPrior to installation of replacement gate systems, the design and the proposed gate systems along with the installation procedure should be submitted for review.Installation of the gate and operator should be in accordance with manufacturers recommendations. The best method of mounting a gate - lifting mechanism is to an embedded wall thimble. The second choice is to a flanged pipe. The flange must be true in order to provide a proper sealing surface. If a flange is to be welded to an existing pipe in the field, in-place machining of the flange will more than likely be required after completion of the welding process. Warping of the flange is almost certain due to the heat associated with the welding process. If there is no existing thimble or flanged pipe, gates are available that mount to a concrete wall.2.11.4.2TESTINGAfter installation the Contractor shall test each gate for satisfactory operation and water tightness against maximum operating pressure insofar as practicable. If an electric or hydraulic operator is used, limit switches shall be adjusted following the manufacturers instructions.A field leakage test shall be perform by the Contractor after installation of the gates. The manufacturer shall be notified of the test so as to allow sufficient time to enable a representative of the manufacturer to be present at the test site. After all adjustments have been made and the mechanism properly lubricated, each gate slide shall be operated through one complete cycle as a final check on proper operation before starting the leakage test.2.11.5 MEASUREMENT/BASIS OF PAYMENTFabrication, supply and installation of gates in the Bill of Quantities are a lump sum item. No measurement of area will be made for such item.The quantity determined as provided above, shall be paid for at the contract unit price per kilogram, which price and payment shall constitute full compensation for furnishing, galvanizing, fabricating, radio graphing, magnetic particle inspection, delivering, erecting ready for use, and painting all steel and other metal including all labor, equipment, tools and incidentals necessary to complete the work.

ITEM 2.12INTAKE GATE FABRICATION AND INSTALLATION(Same as Item 2.11)

ITEM 2.13RAILINGS, AND OTHER STEELWORKS2.13.1GENERAL2.13.1.1DESCRIPTIONThis item shall cover supply, fabrication and installation of metal railings and other steel works as shown on the Plans including labor, materials, equipment and tools necessary to complete the works.2.13.2MATERIAL REQUIREMENTSThe structural adequacy of the metal stair design is the responsibility of the designer or professional of record.a.Railing assembly shall withstand a minimum concentrated load of two hundred (200) pounds or ninety and seven tenths (90.7) kilogram applied vertically downward or horizontally in any direction, but not simultaneously, at any point on the top rail.Codes may vary in method of application and magnitude of load. Governing code should be checked for specific requirements. Most codes require a two hundred (200) pound minimum concentrated load applied in any direction at any point on the top rail.b. Railing assembly shall withstand a minimum uniform load of fifty (50) pounds per foot or two hundred ninety eight (298) kilograms per meter applied horizontally or vertically downward, but not simultaneously, on the top rail.Some codes have requirements for uniform loading on the top rails. Most codes require a fifty (50) pounds per foot minimum uniform load. Uniform loads are not to be applied concurrently with concentrated loads.c.Guard intermediate rails, balusters, panel fillers, posts or cables shall be designed for a uniform load of not less than fifty (50) pounds per square foot applied horizontally over the gross area of the guard of which they are part. Reactions due to this loading need not be added to the loading specified for the main supporting members of the guard.d.Railing frame components and cable hardware shall be designed to withstand loads encountered without excessive deflection or distortion when cables are tensioned to conform to building code requirements.2.13.2.1DELIVERY, STORAGE AND HANDLINGMaterials shall be delivered on the job site in good condition and properly protected against damage to finished surfaces.Materials shall be stored in a location and in a manner to avoid damage and in a clean, dry location away from uncured concrete and masonry. Stacking shall be don