Strength and Durability of Flowing Concrete using DARACEM® 19 – TB-0603
A series of tests was conducted to evaluate the durability of flowing, superplasticized concrete. Three separate loads of concrete were produced with various addition rates of DARACEM® 19 to produce concrete with slumps ranging from 178 mm to 254 mm (7 in. to 10 in.). Standard tests were performed, including air content, slump and unit weight. Two beams were cast from each mix for freeze-thaw durability analysis (ASTM Method C666, Procedure B, Rapid Freezing in Air and Thawing in Water).
The test results show that DARACEM® 19 provided compressive strengths 2 to 5 MPa (250 to 700 psi) higher than the reference mix even at equal water-cement ratio. Thus, DARACEM® 19 provides a double benefit of increased workability (higher slumps), coupled with higher strengths, at the same cement content. This is due to the greatly improved dispersion of cement provided by the DARACEM® 19. The data also shows relative durability factors 95% and more of the reference mix after 300 freeze-thaw cycles.
Summary
To summarize, flowing concrete can be made which gives an increase in the degree of workability, coupled with higher compressive strengths, as well as proper freeze-thaw durability.
Flowing Concrete with DARACEM® 19, Summary of Test Data
| Test Designation | A | B | C |
|---|---|---|---|
| Cement, kg/m3 (lbs/yd3) | 335 (564) | 335 (564) | 335 (564) |
| Sand, kg/m3 (lbs/yd3) | 783 (1320) | 783 (1320) | 783 (1320) |
| Coarse agg, kg/m3 (lbs/yd3) | 1038 (1750) | 1038 (1750) | 1038 (1750) |
| Water, kg/m3 (lbs/yd3) | 177 (298) | 174 (293) | 177 (299) |
| W/C ratio | 0.53 | 0.52 | 0.53 |
| Daravair®, mL/m3 (oz/yd3) | 155 (4.0) | 164 (4.25) | 164 (4.25) |
| Before DARACEM® 19 | |||
| Air, % | 6.0 | 6.5 | 7.0 |
| Slump, mm (in.) | 121 (4.75) | 114 (4.50) | 127 (5.00) |
| Unit weight, kg/m3 (lbs/ft3) | 2307 (144.0) | 2300 (143.6) | 2281 (142.4) |
| Yield, m3 (ft3) | 1.01 (27.31) | 1.02 (27.35) | 1.02 (27.62) |
| After DARACEM® 19 | |||
| Amount of DARACEM® 19 added, mL/100 kg (oz/100 lbs) | 0.0 (0.0) | 456 (7.0) | 652 (10.0) |
| Air, % | N/T | 6.2 | 6.2 |
| Slump, mm (in.) | N/T | 178 (7.00) | 254 (10.00) |
| Temperature, °C (°F) | 24 (76) | 26 (79) | 26 (78) |
| Unit weight, kg/m3 (lbs/ft3) | N/T | 2320 (144.8) | 2320 (144.8) |
| Yield, m3 (ft3) | N/T | 1.00 (27.12) | 1.01 (27.16) |
| Compressive Strength, MPa (psi) | |||
| 3 day % of reference | 19.5 (2830) 100 | 23.2 (3370) 119 | 23.0 (3340) 118 |
| 7 day % of reference | 24.6 (3570) 100 | 27.4 (3970) 111 | 26.4 (3830) 107 |
| 28 day % of reference | 33.7 (4890) 100 | 37.2 (5390) 107 | 37.5 (5440) 109 |
| 56 day % of reference | 37.7 (5460) 100 | 40.2 (5830) 107 | 41.0 (5950) 109 |
| Freeze-Thaw Durability | |||
| Durability factor % of reference | 98.5 100 | 95.0 96.0 | 95.0 96.0 |
