High-Performance Concrete Chapter 17-High-Performance Concrete-EB101 –Design and Control of Concrete Mixtures—7th Canadian Edition, 2002.

High-Performance Concrete CSA A23.1 Definition — Concrete that meets performance requirements that cannot always be achieved routinely by using only conventional materials and normal mixing, placing, and curing practices. The requirements may involve enhancements of placement and compaction without segregation, long-term mechanical properties, early-age strength, toughness, volume stability, or service life in severe environments. High-Performance Concrete

Characteristics of High-Performance Concretes High strength High early strength High modulus of elasticity High abrasion resistance High durability and long life in severe environments Low permeability and diffusion Resistance to chemical attack Fig. 17-1. High-performance concrete is often used in bridges. (70017) High-Performance Concrete

Characteristics of High-Performance Concretes High resistance to frost and deicer scaling damage Toughness and impact resistance Volume stability Ease of placement Compaction without segregation Inhibition of bacterial and mould growth Fig. 17-1. High-performance concrete is often used in tall buildings. (70023) High-Performance Concrete

Materials Used in High- Performance Concrete (1) Primary Contribution/Desired Property Portland cement Cementing mat’l / durability Blended cement Cementing material / durability / high strength Fly ash / slag / silica fume Calcined clay*/ metakaolin* Calcined shale* Superplasticizers Flowability High-range water reducers Reduce water to cement ratio Hydration control admix. Control setting Table 17-1. Materials Used in High-Performance Concrete High-Performance Concrete *No significant use in Canada at this time

Materials Used in High- Performance Concrete (2) 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 agg. Improve workability/reduce paste Table 17-1. Materials Used in High-Performance Concrete High-Performance Concrete

Selected Properties of High- Performance Concrete (1) Property Test Method Criteria that may be specified High Strength CSA A23.2-9C 40-140 MPa @ 28 to 91 days H-E Comp. Strength 20-30 MPa @ 3-12 hrs.or 1-3 days H-E Flex. Strength CSA A23.2-8C 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% Table 17-2. Selected Properties of High-Performance Concrete High-Performance Concrete

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 to deicer scaling ASTM C 672 Rating 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 Table 17-2. Selected Properties of High-Performance Concrete High-Performance Concrete

Typical HPC Mixes Used in Structures (1) Material, kg/m3 Mix 1 Mix 2 Material Water 151 145 H2O Reducer,L/m3 1.6 1.7 Cement 311 398* Retarder, L/m3 — Fly ash 31 45 Air Content, % 7±1.5 5-8 Slag 47 HRWR or plasticizer, L/m3 2.1 3 Silica Fume 16 32* w/cm 0.37 0.30 C.A. 1068 1030 ƒc′ at 28-d, MPa 59 F.A. 676 705 ƒc′ at 91-d, MPa 60 Table 17-3 Typical High-Performance Concretes Used in Structures Mix 1 Wacker Drive bi-level roadway, Chicago, 2001 Mix 2 Confederation Bridge, Northumberland Strait, PEI / N>B. 1997 Mix 1 Wacker Drive bi-level roadway Chicago, 2002 Mix 2 Confederation Bridge PEI / NB 1997 High-Performance Concrete *Originally used Blended cement. P.C and silica fume have been separated for comparison purposes.

Typical HPC Mixes Used in Structures (2) Material, kg/m3 Mix 3 Mix 4 Material Water 135 145 H2O Reducer,L/m3 — 1.0 Cement 500 335* Retarder, L/m3 1.8 Fly ash Air Content, % Slag 125 HRWR or plasticizer, L/m3 14 6.5 Silica Fume 30 40* w/cm 0.27 0.29 C.A. 1100 1130 ƒc′ at 28-d, MPa 93 99 F.A. 700 695 ƒc′ at 91-d, MPa 107 104 Table 17-3. Typical High-Performance Concretes Used in Structures Mix 3 La Laurentienne Building, Montreal, 1984 Mix 4 BCE Place Phase 2, Toronto, 1993 High-Performance Concrete *Originally used Blended cement. P.C and silica fume have been separated for comparison purposes.

HIGH-EARLY-STRENGTH CONCRETE High-early compressive strength CSA A23.2-9C 20 to 30 MPa at 3 to 12 hours or 1 to 3 days High-early flexural strength CSA A23.2-8C 2 to 4 MPa High-Performance Concrete

HIGH-EARLY-STRENGTH (1) CONCRETE May be achieved by — Type 30 or HE high-early-strength cement High cement content 400 to 600 kg/m3 Low w/cm (0.20 to 0.45 ) Higher freshly mixed concrete temperature Higher curing temperature High-early-strength can be obtained by using one or a combination of the following, depending on the age at which the specified strength must be achieved and on job conditions. High-Performance Concrete

HIGH-EARLY-STRENGTH (2) CONCRETE May be achieved by — Chemical admixtures Silica fume (or other SCMs) Steam or autoclave curing Insulation to retain heat of hydration Special rapid hardening cements High-early-strength can be obtained by using one or a combination of the above, depending on the age at which the specified strength must be achieved and on job conditions. High-Performance Concrete

Strength Data for Fast-Track Bonded Overlay Age Compressive strength, MPa Flexural strength, MPa Bond strength, MPa 4 hours 1.7 0.9 6 hours 7.0 2.0 1.1 8 hours 13.0 2.7 1.4 12 hours 17.6 3.4 1.6 24 hours 23.9 4.2 2.1 7 days 34.2 5.0 28 days 40.7 5.7 2.5 A fast-track concrete mixture used for a bonded concrete highway overlay consisted of 380 kg of Type 30 cement, 42 kg of Type C fly ash, 6 1/2% air, a water reducer, and a water-to-cementing materials ratio of 0.4. Strength data for this 40-mm slump concrete are given in Table. Table 17-4. Strength Data for Fast-Track Bonded Overlay High-Performance Concrete

Strength Development of HE Strength Concrete Cement = 390 kg/m3 w/c = 0.46 Fig. 17-2. Strength development of a high-early strength concrete mixture using 390 kg/m3 of rapid hardening cement, 676 kg/m3 of sand, 1115 kg/m3 of 28 mm nominal max. size coarse aggregate, a water to cement ratio of 0.46, a slump of 100 to 200 mm, and a plasticizer and retarder. Initial set was at one hour (Pyle 2001). High-Performance Concrete

Strength Development of HE Strength Concrete Cement = 504 to 528 kg/m3 w/c = 0.46 Fig. 17-3. Strength development of high-early strength concrete mixtures made with 504 to 528 kg/m3 of Type 30 or Type 20/30 cement, a nominal maximum size coarse aggregate of 28 mm, a water to cement ratio of 0.30, a plasticizer, a hydration control admixture, and an accelerator. Initial set was at one hour (Pyle 2001). High-Performance Concrete

Effect of Blanket Insulation Fig. 17-4. Effect of blanket insulation on fast-track concrete. The concrete had a Type 10 cement content of 421kg/m3 and a water to cement ratio of 0.30 (Grove 1989). High-Performance Concrete

High-Strength Concrete 90% of R/M concrete 20 MPa - 40 MPa @ 28-d (most 30 MPa – 35 MPa) High-strength concrete by definition — 28-day comp. strength ≥ 70 MPa Explosive nature of high-strength concrete upon failure when tested in compression. (53272) Traditionally specified strength of concrete has been based on 28-day test results. For high-rise construction however, the process of construction is such that lower floors are not fully loaded for periods up to a year or more---therefore, compressive strengths based on 56- or 91 days test results are now commonly specified. This also achieves significant economies in material costs. High-Performance Concrete

High-Strength Concrete Materials Cements — Cast-in-Place HPC—Type 10E-SF & Ternary Blended Precast—Type 30 and Type 10E-SF Base selection on mortar-cube tests + comparative conc. strs. @ 28, 56, 91-d Use cement yielding highest concrete strength at extended ages (91-days) Cement should have min. 7-day mortar cube strength of approx. 30 MPa Type 10E-SF and Ternary Blended meet CSA A362 and Type 30 meets CSA A5 Standard. High-Performance Concrete

High-Strength Concrete Materials Aggregates — 10 mm – 14 mm nominal max. size give optimum strength Combining single sizes for required grading allows for closer control and reduced variability in concrete For 70 MPa and greater, the FM of the sand should be 2.8 – 3.2. (Lower may give lower strengths and sticky mixes). High-Performance Concrete

High-Strength Concrete Materials Supplementary Cementing Materials — Fly ash, silica fume, or slag often mandatory SCM dosage rate 5% to 20% or higher by mass of cementing material. Some specs. – silica fume 10% max. High-Performance Concrete

High-Strength Concrete Materials Admixtures — Use of water reducers, retarders, HRWRs, or superplasticizers — mandatory Air-entraining admix. not necessary or desirable in protected H-S concrete. Where durability in a F/T environment is required ie. bridges, piers, parking structures— air is mandatory Recent studies lead to the belief that — mixes with a w/cm ≥ 0.30 require air, those < 0.25 do not High-Performance Concrete

High-Strength Concrete Mixing — Central Plant or Truck Mixers Truck mixing — reduce loads to 90% of rated capacity Prequalification of concrete suppliers is recommended Field trials with full loads delivered to the site or a mock-up are essential to assess the batching, mixing, transporting and placing systems to be used. High-Performance Concrete

High-Strength Concrete Placing, Consolidation, and Curing — (1) Delays in delivery and placing must be eliminated Consolidation very important in achieving strength of H-S concrete Slump generally 180 mm to 220 mm High-Performance Concrete

High-Strength Concrete Placing, Consolidation, and Curing — (2) Little if any bleeding Imperative that fog or evaporation retarders be applied immediately after strike off to minimize plastic shrinkage and crusting 7 days moist curing. High-Performance Concrete

Mix Proportions and Properties of High-Strength Concrete C + SF + FA C + SF Cement, Type 10, kg/m3 475 564 Silica fume, kg/m3 24 89 Fly ash, kg/m3 59 — HRWR Type F, L/m3 11.6 20.11 Retarder, Type D, L/m3 1.05 1.46 Water to cementing materials ratio 0.29 0.22 Slump, mm 248 254 Compressive strength, 28-d, MPa 92 117 Compressive strength, 91-d, MPa 105 124 Modulus of elasticity, 91-d, GPa 49.9 56.5 Drying shrinkage, 369-d, millionths 677 527 Table 17-5. Mixture Proportions and Properties of Commercially Available High-Strength Concrete. (Burg and Ost 1994) High-Performance Concrete

Two Union Square Seattle, 1988 Cement: 513 kg/m3 w/c: 0.25 Silica fume: 43 kg/m3 Fine aggregate: 685 kg/m3 HRWR: 15.7 L/m3 28d strength: 119 MPa 91d strength: 145 MPa Fig. 17-5. The Two Union Square building in Seattle used concrete with a designed compressive strength of 131 MPa in its steel tube and concrete composite columns. High-strength concrete was used to meet a design criteria of 41 GPa modulus of elasticity. (59577) High-Performance Concrete

High-Durability Concrete 1970s and 1980s focus on — High-Strength HPC Today focus on concretes with high durability in severe environments resulting in structures with long life — High-Durability HPC High-Performance Concrete

High-Durability Concrete Durability Issues That HPC Can Address Abrasion Resistance Blast Resistance Permeability Carbonation Freeze-Thaw Resistance Chemical Attack Alkali-Silica Reactivity (helps combat) Corrosion rates of rebar (high resistivity) High-Performance Concrete

High-Durability Concrete Confederation Bridge, Northumberland Strait, Prince Edward Island/New Brunswick, 1997 Cement: 398 kg/m3 Fly ash: 45 kg/m3 Silica fume: 32 kg/m3 w/cm: 0.30 Water Reducer: 1.7 L/m3 HRWR: 15.7 L/m3 Air: 5-8% 91-d strength: 60 MPa The Confederation Bridge across the Northumberland Strait between Prince Edward Island and New Brunswick has a 100-year design life. This bridge contains HPC designed to efficiently protect the embedded reinforcement. The concrete had a diffusion coefficient of 4.8 x 10-13 at six months (a value 10 to 30 times lower than that of conventional concrete). The electrical resistivity was measured at 470 to 530 ohm-m, compared to 50 for conventional concrete. The design required that the concrete be rated at less than 1000 coulombs. The high concrete resistivity in itself will result in a rate of corrosion that is potentially less than 10 percent of the corrosion rate for conventional concrete High-Performance Concrete

Self-Consolidating Concrete Self-consolidating concrete (SCC) also known as self-compacting concrete — flows and compacts on its own developed in 1980s — Japan Increased amount of Fine material (i.e. fly ash or limestone filler) HRWR/Superplasticizers Strength and durability same as conventional concrete Total content of particles finer than 160 μm sieve has to be high (usually 520 – 560 kg/m3 ) HRWRs based on polycarboxylate ethers typically used to plasticize the mix. Very sensitive to fluctuation in water content therefore stabilizers such as polysaccarides are used High-Performance Concrete

Self-Consolidating Concrete Fig. 17-6. Examples of materials used in regular concrete and self-consolidating concrete by absolute volume. High-Performance Concrete

SCC for Power Plant in Pennsylvania—Mix Proportions Portland cement (Type 10) 297 kg/m3 Slag cement 128 kg/m3 Coarse aggregate 675 kg/m3 Fine aggregate 1,026 kg/m3 Water 170 kg/m3 Superplasticizer ASTM C 494, Type F (Polycarboxylate-based) 1.3 L/m3 AE admixture as needed for 6% ± 1.5% air content Project: Seward Power Plant, New Florence, Pa. High-Performance Concrete

J-Ring Test for SCC High-Performance Concrete Fig. 17-7. J-ring test. Photo courtesy of VDZ. The number of rods has to be adjusted depending on the maximum size aggregate in the SCC mix. High-Performance Concrete

Reactive-Powder Concrete (RPC) High strength — 200 MPa (can be produced to 810 MPa) Very low porosity These properties achieved by optimized particle packing and low water content Fig. 17-8. Freshly-mixed reactive-powder concrete. High-Performance Concrete

Reactive Powder Concrete (RPC) Properties achieved by — No coarse agg. only fine powders (sand, crushed quartz, silica fume with grain sizes 0.02 – 300 μm) Optimized grain size distribution Post-set heat treatment Steel and synthetic fibres (about 2% by volume) Superplasticizers — w/c < 0.2 High-Performance Concrete

Mechanical Properties of RPC Property Unit 80 MPa RPC Compressive strength MPa 80 200 Flexural strength 7 40 Tensile strength 8 Modulus of Elasticity GPa 60 Fracture Toughness 103 J/m2 <1 30 Freeze-thaw RDF 90 100 Carbonation mm 2 Abrasion 10-12 m2/s 275 1.2 Table 17-6. Typical Mechanical Properties of Reactive Powder Concrete (RPC) compared to an 80-MPa Concrete (Perry 1998). High-Performance Concrete

Reactive Powder Concrete Fig. 17-9. The Sherbrooke footbridge in Quebec, built in 1997, is North America’s first reactive-powder concrete structure. (68300) High-Performance Concrete