High-Performance Concrete
ByDr. Adel El Kordi
ProfessorStructural Engineering
Department Faculty of EngineeringAlexandria University
CIVE 570Spring 2012
Characteristics of High-Performance Concretes
1. High strength
2. High early strength
3. High modulus of elasticity
4. High abrasion resistance
5. High durability and long life in severe environments
6. Low permeability and diffusion
7. Resistance to chemical attack
Characteristics of High-Performance Concretes
8. High resistance to frost and deicer scaling damage
9. Toughness and impact resistance
10.Volume stability11.Ease of placement12.Compaction without
segregation13.Inhibition of bacterial and
mold growth
Materials Used in High- Performance Concrete (1)
Material Primary Contribution/Desired Property
Portland cement Cementing material / Durability
Blended cementCementing material /
Durability / High strength
Fly ash / Slag / Silica fume
Calcined clay/ Metakaolin
Calcined shale
Superplasticizers Flowability
High-range water reducers Reduce water-cement ratio
Hydration control admix. Control setting
Materials Used in High- Performance Concrete (2)
Material Primary contribution/Desired property
Retarders Control setting
Accelerators Accelerate setting
Corrosion inhibitors Control steel corrosion
Water reducers Reduce cement and water content
Shrinkage reducers Reduce shrinkage
ASR inhibitors Control alkali-silica activity
Polymer/latex modifiers Durability
Optimally graded aggr. Improve workability/reduce paste
Selected Properties of High- Performance Concrete (1)
Property Test Method
Criteria that may be specified
High Strength ASTM C 39 40-140 MPa @ 28 to 91 days
H-E Comp. Strength ASTM C 39 20-30 MPa @ 3-12 hrs.or 1-3 days
H-E Flex. Strength ASTM C 78 2-4 MPa @ 3-12 hrs.or 1-3 days
Abrasion Resistance
ASTM C 944 0-1 mm depth of wear
Low Permeability ASTM C 1202 500 to 2000 coulombs
Chloride Penetration
AASHTO T 259/260
Less than 0.07% Cl at 6 months
High Resistivity ASTM G 59 —Low Absorption ASTM C 642 2% to 5%
Selected Properties of High- Performance Concrete (2) Property Test Method Criteria that may be
spec.Low diffusion coeff. Wood, Wilson, Leek 1000 x 10-13 m/s
Resistance to chemical attack
sat. solution in wet/dry environment No deterioration after 1 yr.
Sulphate attack ASTM C 1012 0.1% max. exp. @ 6 mos.
High Mod.of Elast. (E) ASTM C 469 More than 40 GPa
High resistance to F/T damage
ASTM C 666 Procedure A
Durability Factor 95-100 @ 300 -1000 cycles
High resistance todeicer scaling
ASTM C 672Rating 0-1 or mass loss 0 to 0.5 kg/m3 after 50-300 cycles
Low shrinkage ASTM C 157 Less than 400 millionths
Low creep ASTM C 512 Less than normal concrete
High-Early-Strength Concrete
n High-early compressive strength
ASTM C 39 (AASHTO T 22)
20 to 28 MPa (3000 to 4000 psi)
at 3 to 12 hours or 1 to 3 days. n High-early flexural strength
ASTM C 78 (AASHTO T 97)
2 to 4 MPa (300 to 600 psi)
at 3 to 12 hours or 1 to 3 days.
High-Early-Strength Concrete
1. Type III or HE high-early-strength cement2. High cement content 400 to 600 kg/m3 .3. Low water-cementing materials ratio (0.20
to 0.45 by mass)4. Higher freshly mixed concrete temperature5. Higher curing temperature
May be achieved by —
High-Early-Strength Concrete
6. Chemical admixtures
7. Silica fume (or other supplementary cementing materials)
8. Steam or autoclave curing
9. Insulation to retain heat of hydration
10. Special rapid hardening cements
May be achieved by —
n Cement: (865 lb/yd3)
n w/c: 0.25n Silica fume: (72 lb/yd3)n Fine aggr.: (1155 lb/yd3)n HRWR: (420
oz/yd3)n 28d strength: (17,200
psi)n 91d strength: (21,000
psi)
n Cement: 513 kg/m3
n w/c: 0.25n Silica fume: 43 kg/m3
n Fine aggr.: 685 kg/m3
n HRWR: 15.7 L/m3
n 28d strength: 119 MPan 91d strength: 145 MPa
Two Union Square Seattle, 1988
High-Durability Concrete
n 1970s and 1980s focus on High-Strength HPC
n Today focus on concretes with high durability in severe environments resulting in structures with long life
High-Durability Concrete
n Abrasion Resistancen Blast Resistancen Permeabilityn Carbonationn Freeze-Thaw Resistancen Chemical Attackn Alkali-Silica Reactivity
(helps combat)n Corrosion rates of rebar
(high resistivity)
Durability Issues That HPC Can Address
n Cement: 398 kg/m3 (671 lb/yd3)
n Fly ash: 45 kg/m3 (76 lb/yd3)
n Silica fume: 32 kg/m3 (72 lb/yd3)
n w/c: 0.30n Water Red.: 1.7 L/m3 (47
oz/yd3)n HRWR: 15.7 L/m3 (83
oz/yd3)n Air: 5-8%n 91d strength: 60 MPa (8700
psi)
High-Durability ConcreteConfederation Bridge, Northumberland Strait, Prince Edward Island/New Brunswick, 1997
Self-Consolidating Concrete
n Developed in 1980s — Japann Increased amount of
u Fine material (i.e. fly ash or limestone filler)
u HRWR/Superplasticizersn Strength and durability same as
conventional concrete
Self-consolidating concrete (SCC) also known as self-compacting concrete —flows and consolidates on its own
Portland cement (Type I) 297 kg/m3 (500 lb/yd3)
Slag cement 128 kg/m3 (215 lb/yd3)
Coarse aggregate 675 kg/m3 (1,137 lb/yd3)
Fine aggregate 1,026 kg/m3 (1,729 lb/yd3)
Water 170 kg/m3 (286 lb/yd3)
Superplasticizer ASTM C 494, Type F (Polycarboxylate-based) 1.3 L/m3 (35 oz/yd3)
AE admixture as needed for 6% ± 1.5% air content
SCC for Power Plant in Pennsylvania—Mix Proportions
Reactive-Powder Concrete (RPC)
n Properties:u High strength — 200 MPa
(can be produced to 810 MPa) u Very low porosity
n Properties are achieved by:u Max. particles size 300 mu Optimized particle packingu Low water contentu Steel fibersu Heat-treatment
Mechanical Properties of RPC
Property Unit 80 MPa RPCCompressive strength MPa (psi) 80 (11,600) 200 (29,000)
Flexural strength MPa (psi) 7 (1000) 40 (5800)
Tensile strength MPa (psi) 8 (1160)
Modulus of Elasticity GPa (psi) 40 (5.8 x 106) 60 (8.7 x 106)
Fracture Toughness 103 J/m2 <1 30
Freeze-thaw RDF 90 100
Carbonation mm 2 0
Abrasion 10-12 m2/s 275 1.2