High Performance Concrete & Durability of Concrete
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Transcript of High Performance Concrete & Durability of Concrete
INTER COLLEGE E-POSTER COMPETITION BY ULTRA TECH (at B.V.M. Engineering College) INSTITUTE:
A. D. PATEL INSTITUTE OF TECHNOLOGY (Civil Engg.) GROUP MEMBERS:
1. Abhal Gudhka2. Kalpesh Bhatti3. Nilesh Balasara4. Satish Patel
HPC & DURABILITY OF
CONCRETE
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
DIFFERENCE
Conventional Mix High Performance Concrete
Generally designed on the basis of compressive strength
It may not meet many functional requirements such as impermeability, resistance to frost, thermal cracking.
Concrete of required performance
Good workability, high durability and high strength are the salient features of HPC.
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
CRITERIA FOR MATERIAL SELECTION &MAJOR FACTOR AFFECTING DURABILITY1. Ease of placement2. Long-term mechanical properties3. Early-age strength4. Toughness5. Life in severe environment6. Volume stability
High permeability• High w/c ratio• Poor grading• Poor compaction• Poor curing
Ingress• Water(sorptivity)• Fluid(permeation)
• Vapour or gas ions(diffusion)
Deterioration• Corrosion• Micro-cracking
Ease in construction
DurabilityMechanical properties
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
METHODS FOR ACHIEVING HIGH PERFORMANCE
Reduced capillary
pores
No fluid movemen
t
Increased physical
resistance
Chemically active binding
sites
Prevents entry of
aggressive ions
Increased physical
resistance
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
DURABILITY OF CONCRETE Durability may be defined as the property
required for fulfilling all the service requirement of a structure during its intended life with the expected maintenance.
Low durability results in cracking, spalling and corrosion.
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
LOW DURABILIT
Y
CrackingShrinkage,
Heat of hydration
Carbonation
Reduction in pH value
Alkali-silica
reactionExpansive
gel formation
Chemical attack
Sulphate attack,
Chloride attack
Physical aggressio
nFreeze-thaw,
Abrasion
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
ADMIXTURES USED FOR BETTER DURABILITY Mineral admixtures:
Silica fume, Fly ash, Ground granulated blast furnace slag: makes denser and stronger concrete
Chemical admixtures: Plasticizers, Super plasticizers: improves
workability Retarders: prolongs initial setting time Air-entraining agents: better workability,
resistance to freeze-thaw action
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
USE OF FLY ASH
FLY ASH
Greater strengthcombines with free
lime
Low permeabilit
y:High
durability
Prevents destructive expansion :
combines with alkali
Less heat of
hydration: prevents thermal cracking
Reduced efflorescen
ceCombines with salts
ECONOMICAL
ECOFRI
ENDLY
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
HOW PLASTICIZER WORKS
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
APPLICATION OF HPC Bridges High rise buildings Marine structures Tunnels Pavements Nuclear Structures
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
CASE STUDY: THE COMPUTER SCIENCE BUILDING AT YORK UNIVERSITY
HVFA Concrete Mix Proportion (kg/m³)MATERIAL TYPICAL MIX
(30 MPa)JOB MIX(25 MPa)
JOB MIX(30 MPa)
Cement 380 150 170Fly ash 0 150 170Stone 1130 1150 1110Sand 716 850 800Water 171 135 135
W/C ratio 0.45 0.40 0.40
HVFA: High Volume Fly Ash• Relatively easy to place and finish• An early-age (plastic) cracking issue during hot
windy weather was addressed through the use of an evaporation retardant.
01/05/2023HPC & DURABILITY OF CONCRETE A.D.I.T
REFERENCE Concrete Technology (Oxford) Optimizing the Use of Fly Ash in Concrete
By: Michael Thomas, Ph.D., P.Eng., Professor of Civil Engineering, University of New Brunswick
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