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A-1 APPENDIX EXAMPLES OF MIXTURE DESIGNS There are many ways to achieve high early strength while maintaining durability of EOT concrete. The goal is to select the most cost-effective combination of materials that will produce a mixture meeting strength criterion while achieving the desired level of durability. To some degree, this will depend on the environment in which the repair is to be made. For example, in some states, issues of freeze-thaw durability and scaling resistance are not big concerns, and the need for air entrainment is reduced. For the vast majority of states, however, air entrainment must be considered because of the freeze-thaw environment and use of chemical deicers. In this study, several mixture designs were found to provide appro- priate fresh and hardened concrete properties. Mixtures 1, 2, and 3, all of which were made using a vin- sol resin air-entraining agent, provided good performance for 6- to 8-hour EOT concrete: ⢠Mixture 1 â Cement Type: Type I â Cement Content: 525 kg/m3 (885 lb/yd3) â w/c ratio: 0.40 â Accelerator Type: non-chloride â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 427 kg/m3 (720 lb/yd3) natural sand â Average Slump: 140 mm (5.5 in.) â Average Air Content: 5.0 percent â 8-hour Compressive Strength: 16.4 MPa (2,375 psi) â 28-day Compressive Strength: 44.0 MPa (6,400 psi) â 8-hour Flexural Strength: 2.4 MPa (350 psi) ⢠Mixture 2 â Cement Type: Type I â Cement Content: 525 kg/m3 (885 lb/yd3) â w/c ratio: 0.36 â Accelerator Type: non-chloride â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 482 kg/m3 (812 lb/yd3) natural sand â Average Slump: 70 mm (2.75 in.) â Average Air Content: 5.0 percent â 8-hour Compressive Strength: 20.4 MPa (3,000 psi) â 28-day Compressive Strength: 56.3 MPa (8,150 psi) â 8-hour Flexural Strength: 3.0 MPa (435 psi) ⢠Mixture 3 â Cement Type: Type I â Cement Content: 425 kg/m3 â w/c ratio: 0.40 â Accelerator Type: calcium chloride â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 425 kg/m3 (716 lb/yd3) natural sand â Average Slump: 65 mm (2.5 in.) â Average Air Content: 5.6 percent â 8-hour Compressive Strength: 17.0 MPa (2,465 psi) â 28-day Compressive Strength: 53.8 MPa (7,800 psi) â 8-hour Flexural Strength: 2.4 MPa (350 psi) Mixtures 4, 5, and 6, all of which were made using a vin- sol resin air-entraining agent, provided good performance for 20- to 24-hour EOT concrete: ⢠Mixture 4 â Cement Type: Type I â Cement Content: 400 kg/m3 â w/c ratio: 0.43 â Accelerator Type: calcium chloride â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 628 kg/m3 (1,060 lb/yd3) natural sand â Average Slump: 85 mm (3.35 in.) â Average Air Content: 6.6 percent â 20-hour Compressive Strength: 24.5 MPa (3,550 psi) â 28-day Compressive Strength: 46.0 MPa (6,670 psi) â 20-hour Flexural Strength: 3.4 MPa (490 psi) ⢠Mixture 5 â Cement Type: Type I â Cement Content: 400 kg/m3 â w/c ratio: 0.40 â Accelerator Type: non-chloride â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 659 kg/m3 (1,110 lb/yd3) natural sand â Average Slump: 50 mm (2 in.) â Average Air Content: 5.7 percent â 20-hour Compressive Strength: 19.9 MPa (2,890 psi) â 28-day Compressive Strength: 40.6 MPa (5,890 psi) â 20-hour Flexural Strength: 3.8 MPa (550 psi) ⢠Mixture 6 â Cement Type: Type I â Cement Content: 475 kg/m3 â w/c ratio: 0.43 â Accelerator Type: none
â Water Reducer: none â Coarse Aggregate: 1,030 kg/m3 (1,736 lb/yd3) crushed limestone â Fine Aggregate: 659 kg/m3 (1,110 lb/yd3) natural sand â Average Slump: 150 mm (6 in.) â Average Air Content: 5.9 percent â 20-hour Compressive Strength: 17.8 MPa (2,580 psi) A-2 â 28-day Compressive Strength: 39.3 MPa (5,700 psi) â 20-hour Flexural Strength: 3.6 MPa (520 psi) These examples of cement mixtures were identified from the investigations conducted in NCHRP 18-04B. Other suit- able mixtures could be proportioned with the same or differ- ent cements, aggregates, and admixtures.