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Construction application of the concrete Highways and airfields Dr Kafeel Ahmed
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Dr Kafeel Ahmed
Construction application of the concrete
1. Highways and airfields2. Structural concrete3. Massive concrete• Dams• Barrages• Weirs canal linings• Penstocks Properties of each type of concrete are different
Dr Kafeel Ahmed
Construction application of the concreteHighways and airfields
Dr Kafeel Ahmed
Construction application of the concrete
Structural concrete components1. Beams2. Columns3. Slabs 4. Wall panels5. Bridge parts
Dr Kafeel Ahmed
Structural concrete components
Dr Kafeel Ahmed
Bridge parts
Dr Kafeel Ahmed
Massive concrete
1.Barrages
2.Weirs
Dr Kafeel Ahmed
Massive concrete
3.Canals
4.Dams
Dr Kafeel Ahmed
Structure of the concrete
Level of observation
1. Macro level2. Meso level3. Micro level
Dr Kafeel Ahmed
Structure of the concrete
1. Macro levelConcrete is considered as one Material
Dr Kafeel Ahmed
Structure of the concrete
1. Meso level
Dr Kafeel Ahmed
Structure of the concrete
1. Meso levelConcrete is considered as Material consisting of • Cement sand matrix• Coarse aggregates• Cracks• ITZ [interfacial transition zone]
Dr Kafeel Ahmed
Structure of the concrete
1. Micro levelConcrete is considered as Material consisting of • C-S-H• C-H• K-C-S-H• CaCO3
Dr Kafeel Ahmed
Products of Hydration Backscattered electron image (SEM) of the C3S paste hydratedfor 24 h. Magnification: 250·.
Backscattered electron image (SEM) of the alite paste hydratedfor 1 month. Magnification: 250·.[Knut O. Kjellsen a,*, Harald Justnes Norcem AS, R&D Department, N-3950 Brevik, Norway
SINTEF, Civil and Environmental Engineering, N-7465 Trondheim, Norway]
Dr Kafeel Ahmed
Functional Constituents of concrete
1. Binder: That binds the fillers together
2. Fillers: The occupy the space and chemically inert
3. Secondary Binder: They perform their function after the hydration
4. Hydration agent and lubricant: Required for hydration reaction
5. Friction reducers: The increase the distance between binder particles
6. Mineral admixtures: To optimize the packing of particles
Dr Kafeel Ahmed
Functional Constituents of concrete
1.Cement: Reacts with water to produce binding gel
C3S + H2O+C3A+Ca(SO4) C-S-H+ CH+ C3A3CaSO432H2O
C2S+ H2O+C3A+Ca(SO4) C-S-H + CH+ C3A3CaSO432H2O
Ettringinite
Dr Kafeel Ahmed
Functional Constituents of concrete
Products of Hydration•Calcium Silicate Hydrate Gel C-S-H•Calcium Hydroxide Ca(OH)2
•Ettringnite C3A3CaSO432H2O
Advanced concrete technology John Newman
Dr Kafeel Ahmed
Functional Constituents of concrete
Fillers:
Coarse AggregatesFine Aggregates
Dr Kafeel Ahmed
Functional Constituents of concrete
Coarse Aggregates: Particles retained on ASTM sieve No 4
1. Crushed rock particles
www.philstopsoil.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Coarse Aggregates: Particles retained on ASTM sieve No 4
2.River run gravels
www.philstopsoil.com www. or.water.usgs.gov
Dr Kafeel Ahmed
Functional Constituents of concrete
Mineral NatureLimestoneLimestone dolomiteShale:GabbrosBasalt
Dr Kafeel Ahmed
Functional Constituents of concrete
Limestone: Sedimentary rocksLimestone dolomite: Sedimentary rocks
www. horton.ednet.ns.ca www. sciencenetlinks.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Shale/ Marble: Metamorphic rocks
www. geophysics.ou.edu www.earth.ox.ac.uk
Dr Kafeel Ahmed
Functional Constituents of concrete
Gabbros: IgneousBasalt: Igneous
www. videojug.com www. buzzle.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Gabbros: Extrusive mafic volcanic rock
www. volcano.oregonstate.edu www. geology.about.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Basalt: Intrusive mafic volcanic rock
www. itc.gsw.edu www. meteorites.wustl.edu
Dr Kafeel Ahmed
Functional Constituents of concreteFine Aggregates: Naturally crushed rock i.e Sand
Scanning electron microscopic image of sand particles
Dr Kafeel Ahmed
Functional Constituents of concreteFine Aggregates: Naturally crushed rock i.e Sand• Coarse Sand• Fine Sand
www. scottbros.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Hydration agent and lubricant: Water1. It is expressed as a ratio of cement.
2. Water fit for drinking is fit for concrete ACI20093. It reacts with cement4. It lubricates the coarse and fine aggregates5. Hence reduce the friction6. Improve the workability of concrete7. Workability: It is the workdone required to produce full
compaction with minimum loss of homogenity.
Dr Kafeel Ahmed
Functional Constituents of concrete
Secondary Binders: 1. They don't react with water2. These materials react with CH3. They form secondary silicate hydrates K-C-S-H4. These hydrates are strong and tough
Dr Kafeel Ahmed
Functional Constituents of concrete
Scanning electron microscopy of condensed silica fume SFI
Secondary Binders: 1.Micro Silica
Chai Jaturapitakkul*, Kraiwood Kiattikomol, Vanchai Sata, Theerarach LeekeeratikulDepartment of Civil Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
Dr Kafeel Ahmed
Functional Constituents of concrete
Properties:
1. Surface area: Silica fumes due to very large surface area (15000 m2/kg)and high concentration of SiO2(about 92%) are highly reactive.[1]
2. Size: There can be 50,000 to 100,000 particles of silica fumes per cement particle.
Dr Kafeel Ahmed
Functional Constituents of concrete
Properties:
3. Thixotropy: Silica fumes concrete is thixotropic due to ball bearing effect of spherical shaped particles.
4. Reactivity: Increases the rate of hydration of C3S fraction of cement (Andrija 1986)
Dr Kafeel Ahmed
Functional Constituents of concrete
Scanning electron microscopy of original fly ash.Chai Jaturapitakkul*, Kraiwood Kiattikomol, Vanchai Sata, Theerarach LeekeeratikulDepartment of Civil Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
Secondary Binders: 2. Flyash
Dr Kafeel Ahmed
Types of Fly AshType Specific Area Activity Particle ShapeType Specific Area Activity Particle Shape mm22/kg/kgCoarse 1800 Highly Crystalline IrregularFly ash
Medium 5000 Medium Glassy CombinationFly ash
Fine 9000 Highly Glassy Spherical Fly ash
[Chai Jaturapitakkul*, Kraiwood Kiattikomol, Vanchai Sata, Theerarach LeekeeratikulDepartment of Civil Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand]
Dr Kafeel Ahmed
Functional Constituents of concrete
Secondary Binders:
3-Ground granulated blast furnace slag [GGBS]• Produced during the extraction of pig iron• Through the blast furnace
Dr Kafeel Ahmed
Ground granulated blast furnace slag GGBS
Ball mill produced
sample
Vibro mill produed sample
Air flow mill produced sample
Ball mill sample with grinding Assistant
Huiwen Wan*, Zhonghe Shui, Zongshou LinSchool of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei, 430070, PR ChinaReceived 7 November 2002; accepted 17 July 2003
Dr Kafeel Ahmed
Properties of GGBS Concrete
1. Water demand: Reduced water demand (smooth surface
textured GGBS particles attach to the cement grain retarding early hydration hence enhance flluidity)
2. Stiffening time: Increased stiffening time
3. Bleeding:Increased probability of bleeding
Dr Kafeel Ahmed
Properties of GGBS Concrete
4. Form work pressure:Increased form work pressure
5. Curing periods:Longer curing periods
6. Thermal cracking:Reduced thermal cracking
Dr Kafeel Ahmed
Constituents of GGBS in comparason with OPC
• Oxides OPC % GGBS %• CaO 64.0 40.0• SiO2 21.0 36.0• Al2O3 6.0 10.0• Fe2O3 3.0 0.5• MgO 1.5 8.0• SO3 2.0 0.2• K2O 0.8 0.7• Na2O 0.5 0.4
Advanced concrete technology John Newman
Dr Kafeel Ahmed
Hydration mechanism
• OPC+water C-S-H+Ca(OH)2
NaOH KOH
GGBS+Ca(OH)2 C-(N,K)-S-H
NaOH KOHAdvanced concrete technology John Newman
Dr Kafeel Ahmed
Functional Constituents of concrete
4.Metakaolin
www. hpcbridgeviews.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Micro filler:Quartz Sand: Size 200-500 m-6
www.rajasthanminerals.com
Dr Kafeel Ahmed
Functional Constituents of concrete
Micro filler:Quartz powder: Size 1-10 m-6
www. tradekorea.com http://www.37micronsindia.com/snow-white-quartz-powder.htm
Dr Kafeel Ahmed
Functional Constituents of concrete
High range water reducers/ Admixtures
Dr Kafeel Ahmed
Functional Constituents of concreteAdmixturesTypes depending upon function Plasticizer Superplasticizer
Types depending upon origin Lignin based Coal tar or petroleum based
Dr Kafeel Ahmed
Functional Constituents of concrete
Processing• Sulphonation[With concentrated sulphuric acid]
• Polymerization[to improve properties]
• Neutralization[with salts to have ionic effect]
Dr Kafeel Ahmed
Functional Constituents of concrete
Basic Types
1.Sulphonated melamine fomaldehyde(SMF).
2.Sulphonated naphthalene fomaldehyde(SNF).
3.Poly carboxilate ether chains(PCE)Third generation
Dr Kafeel Ahmed
General Proportioning
constituentsconstituents mixture of aggregate and paste paste 30 to 40%
portland cement 7% to 15% by Vol. water 14% to 21% by Vol.
Aggregates 60% to 70% coarse aggregates Fine aggregates
Admixtures
