26

CHAPTER IIIMETHODOLOGYThis chapter presents the method of research used, the research locale and experimental procedures in the conduct of this project.Method of ResearchExperimental method of research was employed by this study. Trials of different percentages of sugarcane ash using 0%, 10% and 20% were experimented in order to determine the compressive strength, block density and water absorption of the mixture in producing concrete hollow blocks.Research Locale The study was conducted at Civil Engineering Laboratory Room specifically at Nueva Ecija University of Science and Technology (NEUST) Gen. Tinio St., Cabanatuan City. The testing of samples was conducted at the Department of Public Works and Highways located in San Isidro, Cabanatuan City.

Actual Procedure of the StudyThe actual procedures of the study consisted of three stages namely: experimental procedure, making cylindrical samples for compression test, and making concrete hollow blocks sample.1. Experimental ProcedureTwo sets of experiments were conducted. First, two trials were made in order to test which of the two sets of percentage will be used. One having 10% of sugarcane ash and the second set had 20% sugarcane ash. Because the second set obtained a bigger value of compressive strength, the researchers used this group as the experimental group. The first group was the control group and the other group as experimental group. For the control group, the researchers provided sample in accordance with standard specifications (such as the ratio of raw materials). For the experimental group, the researchers provided another set of sample as the experimental group and the two sets of group were compared.The following procedures were conducted by the researchers in order to achieve the best product for concrete hollow blocks using sugarcane ash.Group A Control Group 0% sugarcane ash was used in this trial in concrete mix. For stronger concrete, the ratio used was 1:2:3 for cement, sand and gravel respectively. this trial was in accordance with American Standard for Testing MaterialsGroup B Experimental Group 20% of the actual volume of cement was replaced by sugarcane ash

2. Making Cylindrical Samples for Compression TestThe following procedures were conducted by the researchers in making cylindrical samples for compression test. 2.1 The outside of the mold was labelled with an appropriate identification mark, the researchers were careful not to label the lids or tops.2.2 The cylinder molds were placed on a level surface.2.3 The method of consolidation was determined. In this experiment, slump more than 1-inch (25-mm) used rodding instead of vibrating although vibrating is also permitted.2.4 The number of layers of concrete to be placed in the mold was determined. For concrete to be consolidated with the tamping rod, three equal layers for 6 diameter - 12-inch cylinders was placed inside the mold.2.5 The concrete mix was placed in the mold by distributing it around the inside of the mold with the scoop. Then, the layer was consolidated by rodding 25 times evenly distributed around the layer. 2.6 The sides of the mold were tapped 10-15 times with the mallet after each layer in order to close any insertion holes formed by the rod.2.7 The top was stroked off with a wooden float to produce a flat, even and level surface and it was covered with a plastic lid.

3. Determination of Water Absorption

3.1 Full size blocks were completely immersed in clean water in room temperature for 24hours. 3.2 The blocks were removed from the water and allowed to drain for 1 minute by placing them on a 10mm or coarser wire mesh where visible water surface was removed with damped cloth. 3.3 The saturated and surface dry blocks were immediately weighed. 3.4 After weighing all blocks they were dried in a ventilated oven at 100 0c to 1150 0c from less than 24hrs and until 2 successive weighing at intervals of 2hrs showed an increment of lose not greater than 0.2 percent of the last previously determined mass of the specimen.3.5 Three blocks were tested and stored in airtight containers at normal room temperature. No tests were repeated.3.6 The block was weighed on a balance sensitive to lb. (Weight A).3.7 The block was completely immersed in water at a temperature of 14C. to 18C for twenty-four hours. The block shall then be weighed while suspended with a metal wire and completely submerged in water (Weight B).3.8 It was removed from the water and allowed to drain for one minute by placing it in a in. or coarser wire mesh, visible surface water removed with a damp cloth, and the block immediately weighed (Weight C).3.9 The block shall then be dried in an oven at 100C. to 115C. and weighed at twenty-four hour intervals until the loss of weight does not exceed 1 per cent. in a twenty-four hour period (Weight D).3.10 The absorption of the block was calculated as follows :

4. Making Concrete Hollow Blocks Sample4.1 The concrete molds were set up in the exact shape the researchers want the blocks to be.4.2 The researchers manually mix the cement with clean sand. The ratio was 3 parts sand to 1 part cement for normal types of concrete. For stronger concrete, the researchers made the mixture of 2 parts sand to 1 part cement. Note that 0%, 10%, 20% (for trial 1, trial 2 and trial 3, respectively) of cement should be eliminated as this percentage was the percentage of sugarcane ash in the mixture. 4.3 Add gravel or crushed limestone to the mixer. The amount of gravel should roughly equal the combined sand-and-concrete mixture: 3 parts gravel to 2 parts sand, plus 1 part cement. You may need to experiment a bit: With too much gravel, you won't be able to get a smooth consistency to your concrete. 4.4 Slowly water was added into the mixture, stirring it until it reached the right consistency. The mixture was checked as the researchers stirred by scooping a sample of the mixture into a slump cone, measuring it off and seeing how much the mixture settled. To determine that the mixture contained the right combination of ingredients, the mixture should settle about 3 to 4 inches into the cone. 3.5 The mixing was continued for several more minutes until it is consistent throughout. 3.6 A water-based concrete-releasing agent was sprayed inside the mold. This will let the concrete block easily removed from the mold once it has hardened.3.7 The concrete was carefully poured into the mold, and then the top was leveled off using a trowel or a wooden board. The mixture was tapped to help it settle, and to get rid of any air pockets in the mold. 3.8 The concrete was allowed to harden for at least 24 hours before removing it from the mold. Then the concrete was pressed down on the completed block while simultaneously pulling up on the mold. The block is spring free so that the mold can be reused to make more blocks.