Famous Concrete Structure - Trent Global – The Leading ... · Famous Concrete Structure ... as...
Transcript of Famous Concrete Structure - Trent Global – The Leading ... · Famous Concrete Structure ... as...
16/3/2016
1
AD01CTS AD01CTS ‐‐ADVANCED CONSTRUCTION ADVANCED CONSTRUCTION TECHNOLOGY AND SERVICES TECHNOLOGY AND SERVICES
Alfrendo Satyanaga
Lecture 2 Lecture 2 –– Concrete FrameConcrete Frame
Famous Concrete StructureFamous Concrete Structure
• Pantheon, Rome
• Plain concrete
• Construction was started in 118 AD
• Completed in 128 AD
Famous Concrete StructureFamous Concrete Structure
• Coliseum, Rome
• Plain concrete
• Constructed in 70 AD
16/3/2016
2
Famous Concrete StructureFamous Concrete Structure
• Three Gorges Dam, Yangtze River, China
• World’s heaviest concrete structureconcrete structure
• 144 billion pounds of concrete
Famous Concrete StructureFamous Concrete Structure
• Trump international hotel and tower, Chicago, USA
• World’s tallestWorld s tallest concrete building
• 98th floor
• Completed in 2009
Famous Concrete StructureFamous Concrete Structure
• Thomas Heatherwick’s learning hub in NTU, Singapore
• 12 staggered towers12 staggered towers
• 1000 concrete panels
• Completed in 2014
Famous Concrete StructureFamous Concrete Structure
• Bishan central condominium, Singapore
• 500 units500 units
• 38th story building
• 12,000 m2
• Part of sky habitat project in Singapore
• Completed in 2015
16/3/2016
3
Famous Concrete StructureFamous Concrete Structure
• The Interlace, condo residences in Alexandra Road, Singaporeg p
• It will be completed in 2018
• 24th storey building
• 23 blocks, 1040 units
Concrete ApplicationsConcrete Applications
• Residential and commercial buildings
• Bridges, flyovers, culverts
• Dams, tunnels, water tanks
• Swimming poolsSwimming pools
• Roads, runways, pipes
• Foundations, piles, sewers
• Offshore platforms
• Nuclear power stations, radiation shields etc.
• Fire and corrosion protection of steel structures
Concrete FactConcrete Fact
• The most used man‐made material
• The 2nd most used material
• Total value of concrete infrastructure > 17 trillion US dollars
• Annual consumption of concrete in the world
– 18 billion ton/year (as of 2015)
– About 3 tons per person
– More than 10x that of steel
Advantages of Advantages of ConcreteConcrete
• Ease of production from local materials(cost benefit)
• Good compressive strength
• Protection of embedded steel (fireresistance)
• Mouldability to achieve any shape andsize (flexibility of application)
• A durable material in principle
16/3/2016
4
Advantages of Advantages of ConcreteConcrete
• Require less energy to produce thanother construction materials
• Aesthetic possibilities through the useAesthetic possibilities through the useof color, texture and shape
• A material with tailorable properties
Disadvantages of Disadvantages of ConcreteConcrete
• A brittle material with very low tensilestrength and tensile ductility.
• Low strength‐to‐weight ratio (even incompression)compression)
• Prone to chemical attack
• Undergoes irreversible shrinkage due tomoisture loss
• Creep significantly under an appliedload
What is Concrete?What is Concrete?
• Concrete is made by mixing:
– Cement
– Fine aggregatesgg g
– Coarse aggregates
– Water
Concrete AdmixtureConcrete Admixture
• An additional material, known as admixture, is
sometimes added to modify certain properties of
concrete
16/3/2016
5
Concrete AdmixtureConcrete Admixture AbsorptionAbsorption
Internal impervious
Pores partially filled
Free moisture
Oven dry mass, WD
Air dry-moisture condition,
Wm
Saturated surface dry-
moisture condition,
WSSD = WD +WP
Moist-moisture condition,
Wm
AbsorptionAbsorption
• Absorption (A) is the moisture content
when the aggregates are in saturated
D
DSSD
W
WWA
surface dry condition (SSD)
Free MoistureFree Moisture
• Free moisture is the moisture content
(M) in excess of the SSD condition
D
Dm
W
WWM
AMmoistureFree
16/3/2016
6
Aggregates in Concrete Aggregates in Concrete Functions of Aggregates in Concrete Functions of Aggregates in Concrete
• Reduce costs
• Modify properties of concrete
• Reduce dry shrinkage
AdmixturesAdmixtures
• Admixtures are substances that are introduced into a batch of concrete during orof concrete, during or immediately before its mixing, in order to alter or improve the properties of the fresh or hardened concrete or both
Use of AdmixturesUse of Admixtures
• To improve the workability of the fresh concrete
• To reduce water content for a given workability thereby increasing the strengthworkability thereby increasing the strength
• To increase the durability of hardened concrete
• To retard setting time or to increase it
16/3/2016
7
Use of AdmixturesUse of Admixtures
• To impart colour to concrete
• To maintain volume stability by reducing or offsetting shrinkage during concreting
T i i f i• To increase concrete resistance to freezing and thawing
Reinforced Concrete Reinforced Concrete
• Basically made of two materials: plain concrete and steel bars embedded in concrete.
• The tensile strength of concrete is only about• The tensile strength of concrete is only about 10 % of the compressive strength assumed does not resist any tensile forces.
• Reinforcement is designed to carry the tensile strength.
Reinforce Concrete Reinforce Concrete
• Proper bonding is required to prevent slip of the bars
• Proper concrete mixtures are needed to provide adequate impermeability of theprovide adequate impermeability of the concrete against water intrusion and bar corrosion
StressStress‐‐Strain RelationshipStrain Relationship
• As the load is applied, at first strain increases linearly with stress and the concrete behaves as an elastic material.
• After that the curve is no longer linear and• After that the curve is no longer linear and the concrete behaves more like plastic material.
• In the plastic range, if the load is removed, the deformation would not recover.
16/3/2016
8
StressStress‐‐Strain Curve for ConcreteStrain Curve for Concrete Concrete StrengthConcrete Strength
• Concrete generally increases its strength with age.
• A typical variation in strength of an adequately cured Portland Cement Conreteadequately cured Portland Cement Conrete as suggested by BS8110 is:
• BS 8110 does not permit the use of strengths greater than the 28‐day value in calculations
Duration 7 days 1 month 2 months 3 months 6 month 1 year
Strength (N/mm2)
20 30 33 35 36 37
Durability of ConcreteDurability of Concrete
The durability of concrete is influenced by:
• The exposure conditions
• The concrete quality
• The cover to the reinforcement
• The width of any cracks
Specification of ConcreteSpecification of Concrete
• Concrete of a given strength is identified by
its “grade”
• For example Grade 25 concrete has aFor example Grade 25 concrete has a
characteristic cube crushing strength of 25
N/mm2 after 25 days of curing.
• For normal dense aggregate reinforced
concrete use grades of 30, 35, 40
16/3/2016
9
Typical Properties of Structural ConcreteTypical Properties of Structural Concrete
Properties
Compressive strength (MPa) 35
Flexural strength (MPa) 6
Tensile strength (MPa) 3
M d l l ti it (GP ) 28Modulus elasticity (GPa) 28
Tensile strain at failure 0.001
Cofficient of thermal expansion (/oC) 10 x 10‐6
Ultimate shrinkage strain (%) 0.05 – 0.1
Density
Normal weight (kg/m3) 2300
Light weight (kg/m3) 1800
Environmental Impact of ConcreteEnvironmental Impact of Concrete
Enormous raw material and energy consumption
• Global concrete demand > 18 billion tons annually as of 2006
• 1 ton of cement clinker requires 1.7 tons of qnon‐fuel raw materials
• Cement production is 10x more energy intensive than general economy and is account for 2% of global primary energy use (4000‐7500 MJ per tonne of cement)
• Land scarring
Environmental Impact of ConcreteEnvironmental Impact of Concrete
CO2 emission and climate change
• Production of 1 ton of cement clinker generates equal amount of greenhouse gas
C d i f 5 10% f• Cement production accounts for 5‐10% of global CO2 emissions
Surface runoff
Urban heat island
ShrinkageShrinkage
• As concrete hardens there is a reduction in volume.
• This shrinkage is liable to cause cracking of the concreteconcrete.
• It also has the beneficial effect of strengthening the bond between the concrete and the steel reinforcement.
16/3/2016
10
Thermal ExpansionThermal Expansion
• Day‐to day thermal expansion of concrete can be greater than the movements caused by shrinkage.
• When the tensile stresses caused by shrinkage• When the tensile stresses caused by shrinkage or thermal movement exceed the strength of concrete, cracking will occur.
• To control the crack widths, steel reinforcement must be provided close to the concrete surface.
Workability & ConsistencyWorkability & Consistency
• It is desirable that freshly mixed concrete be relatively easy to transport, place, compact and finish without harmful segregation. A concrete mix satisfying these conditions is said to bemix satisfying these conditions is said to be workable.
• It is determined to a large extent by measuring the “consistency” of the mix. Consistency is the fluidity or degree of wetness of concrete.
Factors Affecting WorkabilityFactors Affecting Workability
• Method and duration of transportation.
• Quantity and characteristics of cementingmaterials.
A di h d f• Aggregate grading, shape and surface texture.
• Quantity and characteristics of chemicaladmixtures.
• Amount of water.
• Amount of entrained air.
• Concrete & ambient air temperature.
BleedingBleeding
• Bleeding is the tendency of water to rise to the surface of freshly placed concrete.
• It is caused by the inability of solid constituents of the mix to hold all of theconstituents of the mix to hold all of the mixing water as they settle down.
16/3/2016
11
Working Life of Concrete StructureWorking Life of Concrete Structure Concrete Structural FormConcrete Structural Form
• Flat slab
• Ribbed slab
• Waffle slab
• Band beam and slab
• Deep beam and slab
• Hybrid concrete construction
• Precast
• Tunnel form
Flat SlabFlat Slab
• A reinforced concrete slab supported directly by concrete column without the use of beams
Flat SlabFlat Slab
• Common used in construction
16/3/2016
12
Flat Slab with Drop Panels & Column HeadsFlat Slab with Drop Panels & Column Heads
Use of drop panels:
• Increase shear strength of slab
• Increase negative moment capacity of slab
Stiff th l b d h d d fl ti• Stiffen the slab and hence reduce deflection
Use of column heads:
• Increase shear strength of slab
• Reduce the moment in the slab by reducing the clear or effective span
Benefit of Flat SlabBenefit of Flat Slab
• Flexibility in room layout
• Saving in building height; most economic forms of construction
• Shorter construction time• Shorter construction time
• Ease of installation of M & E services
• Prefabricated welded mesh
• Buildable score
• Can incorporate all edge protection and provide robust working platform (health & safety)
Waffle SlabWaffle Slab
• A type of slab that has two‐directional reinforcement on the outside of the material, giving it the shape of the pockets on a waffle.
Ribbed SlabRibbed Slab
• A pre‐stressed concrete flat half slab with concrete up strands (rib) that are purposely designed to provide the necessary stiffness to the slab for handling
16/3/2016
13
Construction with Waffle SlabConstruction with Waffle Slab
LodytelLodytelCommunication Communication
Development Centre, Development Centre, SpainSpain
It was the first building to use the Holedeck pods for waffle sytem.
ChattrapatiChattrapati ShivajiShivajiTerminal,IndiaTerminal,India
It is recognized for its innovative column design which also
consists waffle design.
Metropol Metropol Parasol,ItalyParasol,Italy
It is the world’s largest structure which is made up of waffle
system.
Advantages of Ribbed and Waffle SlabAdvantages of Ribbed and Waffle Slab
• Flexible
• Relatively light, therefore less foundation costs and longer spans are economic
• Speed of construction
• Fairly slim floor depths
• Robustness
• Excellent vibration control
• Thermal mass
• Good for services integration
• Durable finishes
• Fire resistance
Disadvantages of Ribbed and Waffle SlabDisadvantages of Ribbed and Waffle Slab
• Construction requires strict supervision and skilled labour.
• The casting forms or moulds required for pre‐cast units are very costly and hence only economical when large scale production of similar units are desired.
• Headroom is reduced , hence increased storey height.
• Due to waffle ceiling , it creates problem in lighting facilities and hanging pipes or ducts.
Ribbed and Waffle SlabRibbed and Waffle Slab
• Commonly used as both ceiling and floor slab. They are used in the areas which has huge spans.
• It is often used for industrial, commercial buildings, airports, parking garages, bridges, residences and th t t i i t t bilitother structures requiring extra stability.
• The main purpose of employing this technology is for its strong foundation characteristics of crack and sagging resistance. Waffle slab also holds a greater amount of load compared with conventional concrete slabs.
16/3/2016
14
Construction TechniqueConstruction Technique
1. 2. 3.
Arranging the Framework
Fixing the Connectors
Fixing the Framework
4.Providing a horizontal
connector
5.Placing the
Pods
Construction TechniqueConstruction Technique
6. 7. 8.6.Fixing pods to the connectors
7.Removing framework
8.Removing connectors
9.Removing pods
10.Providing stacking
Band Beam and SlabBand Beam and Slab
• Beam and slab construction involves the use of one or two way spanning slabs onto bems spanning in one or two directions
• Band beams are shallow, wide beams thatBand beams are shallow, wide beams that minimise the overall structural depth.
Deep Beam and SlabDeep Beam and Slab
• Deep beam provide a stiff floor capable of long spans, and able to resist lateral loads.
• To limit the formation of flexural cracks along the sidesthe sides
• Beam can be designed as T or L beams using the slab as a flange
16/3/2016
15
Advantages & Disadvantages of Beam and Advantages & Disadvantages of Beam and Slab ConstructionSlab Construction
Advantages:
• Traditional effective solution.
• Long spans.
• Fast lead time as formwork can be made on siteFast lead time as formwork can be made on site.
Disadvantages:
• Penetrations through beams for large ducts difficult to handle.
• Slow construction.
• Greater floor‐to‐floor height.
PosPos‐‐Tensioned SlabTensioned Slab
Wedge action producing a frictional grip on the wires. Direct bearing from rivet or bolt heads formed at the end of the wiresat the end of the wires. Looping the wires around the concrete.
PosPos‐‐Tensioned SlabTensioned Slab UnbondedUnbonded TendonTendon
• Unbonded tendons are protected by a layer of grease inside a plastic sheath.
16/3/2016
16
UnbondedUnbonded TendonTendon
• Single strand coated with corrosion inhibiting grease and encased in polyethylene sheathing
• PT force is transferred to the concrete by the anchors provided at the ends
StrandStrand
• Strand is made from seven cold drawn high carbon steel wires.
• Seven individuals wires, with six wires helically wound to a long y gpitch around a centre wire.
• All strands should be grade 1860 Mpa
• Strand is mostly available in two nominal size 12.7mm&15.7mm diameter
Unbonded Tendon Unbonded Tendon
16/3/2016
17
Bonded TendonBonded Tendon
• Bond is achieved throughout the length of the tendon by a cementitious matrix called grout
• Post‐tension force along the tendon is a function of the deformation of the concrete
Advantages of Bonded TendonAdvantages of Bonded Tendon
• Higher flexural capacity.• Good flexural crack distribution.• Good corrosion protection.• Flexibility for later cutting of penetrationsFlexibility for later cutting of penetrations.• Easier demolition.
Bonded Tendon Advantages of PostAdvantages of Post‐‐Tension SlabTension Slab
Longer span Overall structural cost Reduced floor to floor height. Deflection &cracks controlDeflection &cracks control Waterproof slabs Early formwork stripping Materials handling Fast construction
16/3/2016
18
Cost Saving of PostCost Saving of Post‐‐Tension SlabTension Slab Disadvantages of PostDisadvantages of Post‐‐Tension SlabTension Slab
Since there are a number of tendons and wires spread inside the post tension slab, it can result in corrosion.
Complexity of work.
Poor workmanship can lead to accidents.
Application of PostApplication of Post‐‐Tension SlabTension Slab
It used to fabricate large members, such as long –span bridge decks of the box – girder type by prestressing together a number of smaller precast unitsprecast units The chief merit of post –tensioning is that it allows the use of curved and stopped‐off cables Post‐tensioning is variably used for strengthening concrete dams, circular prestressing of large concrete tanks & biological shields of nuclear reactors.
Application of PostApplication of Post‐‐Tension SlabTension Slab
16/3/2016
19
Application of PostApplication of Post‐‐Tension SlabTension Slab Hybrid Concrete ConstructionHybrid Concrete Construction
A method of construction which integrates precast concrete and cast in‐situ concrete to make best advantage of their different i h t liti Th d dinherent qualities. The accuracy, speed and high‐quality finish of precast components can be combined with the economy and flexibility of cast in‐situ concrete
Hybrid Concrete ConstructionHybrid Concrete Construction
Hybrid concrete construction can incorporate all the benefits of precasting, (e.g. form, finish, colour, speed, accuracy,
t i hi h lit dprestressing, high‐quality, assured covers and dense and properly cured covercrete) with all the benefits of in‐situ construction (e.g. economy, flexibility, moulability, continuity and robustness).
Hybrid Concrete ConstructionHybrid Concrete Construction
16/3/2016
20
Tunnel FormTunnel Form
A formwork system that allows the contractor to cast walls and slabs in a ll l t t fcellular structure form
The end walls and facades are easily completed with thermally insulated units that can be clad as required.
Tunnel FormTunnel Form
Tunnels can be between 8 – 11 m long and 2.4 – 6.8 m width.
Advantages of Tunnel FormAdvantages of Tunnel Form
Fast and economic construction. Example: earthquake recovery housing
project in Turkey 40,000 units completed in 5 months.
Advantages of Tunnel FormAdvantages of Tunnel Form
Easy to use Smooth concrete surface Doors, windows, electrical pipes ready in
place Wide range of building types No height limitations
16/3/2016
21
Innovations in ConcreteInnovations in Concrete
Ultra‐high performance concrete
Flowing concrete
Self compacting concreteSelf compacting concrete
Fibre reinforced concrete
Nano concrete
UltraUltra‐‐high Performance Concretehigh Performance Concrete
High strength, ductile material formulated
by combining portland cement, silica fume,
quartz flour fine silica sand high‐rangequartz flour, fine silica sand, high range
water reducer, water and steel or organic
fibers.
UltraUltra‐‐high performance concretehigh performance concrete Flowing ConcreteFlowing Concrete
Economical ready mix concrete that allow
maximum flowability without sacrificing
strength by adding water at the jobsitestrength by adding water at the jobsite.
16/3/2016
22
Self Compacting ConcreteSelf Compacting Concrete
Flowing concrete mixture that is able to
consolidate under its own weight.
It is suitable for difficult conditions and inIt is suitable for difficult conditions and in
sections with congested reinforcement.
It can minimize hearing‐related damages on
the worksite that are induced by vibration of
concrete.
Self Compacting ConcreteSelf Compacting Concrete
FibreFibre‐‐Reinforced ConcreteReinforced Concrete
Concrete containing fibrous material which
increases its structural integrity. It contains
short discrete fibres that are uniformlyshort discrete fibres that are uniformly
distributed and randomly oriented. Fibers
include steel fibers, glass fibers, synthetic
fiber and natural fibers – each of which lend
varying properties to the concrete.
FibreFibre‐‐Reinforced ConcreteReinforced Concrete
Welded wire mesh fiber reinforced
concrete
Glass fiberreinforced concrete
Steel fiberreinforced concrete
16/3/2016
23
NanoNano ConcreteConcrete
A concrete made with portland cement particles that are less than 500nm as a cementing agent.
Currently cement particle sizes range from a f i ffew nano‐meters to a maximum of about100 micro meters.
Benefits of Benefits of NanoNano ConcreteConcrete
Lower cost per building site.
Concrete with high initial and final
compressive and tensile strengthscompressive and tensile strengths.
Concrete with good workability.
Tutorial QuestionsTutorial Questions
1. Concrete has been used as construction materials
from small to major projects in the world. Define the
composition of concrete. What is its different from
concrete admixture? State the advantages and
disadvantages of concrete as construction materials.
Tutorial QuestionsTutorial Questions
2. A sample of sand has the following properties:
SSD mass = 1533.74 g
Moist mass = 625.2 gg
Dry mass = 589.9 g
Determine: (a) total moisture content, (b) absorption
rate, (c) free moisture content
16/3/2016
24
Tutorial QuestionsTutorial Questions
3. Reinforced concrete is used as beam, column and slab
in construction.What is reinforced concrete and
what is the purpose to use this material? Describe
three stress‐strain curve of concrete material. What
are factors affecting the durability of concrete?
Tutorial QuestionsTutorial Questions
4. Concrete is commonly used in slab construction.
Describe 3 different types of concrete slabs including
the advantages, disadvantages and the usage of each
slab type. Define the bleeding in concrete
construction.
Tutorial QuestionsTutorial Questions
5. The floor of the boat on top of the Marina Bay Sand
Hotel is constructed using post‐tension slab. Describe
the advantages and disadvantages of this system.
Explain 2 different types of tendons that are used in
post‐tension slabs
Tutorial QuestionsTutorial Questions
6. The latest trend of construction technology using
concrete are hybrid concrete construction and tunnel
form. Describe briefly how both systems are being
constructed. Explain 3 innovations in concrete
technologies.
16/3/2016
25
THANK YOU