Segregation Resistance and Compaction Ability of Concrete with Different Viscosities when Passing through Rebar Gaps
By R. Tani, S. Saito, K. Ohno and K. Uji
Concrete Journal, Vol.58, No.11, Nov. 2020
- Synopsis
- Using four types of water-cement ratio of 40%, 50%, 60%, and 60% with viscosity agent added, we examined the effect of different viscosity and compaction conditions on the filling ability and quality of the cover while focusing on the plastic viscosity of the mortar phase of concrete. A comprehensive evaluation was carried out from mix proportions to the construction results, based on the evaluation of the filling ability of concretes with the same slump, the ultrasonic wave propagation velocity inside and outside the rebar after hardening, and the compressive strength of the sampled cores. For the water-cement ratio of 60%, the addition of viscosity agent was found to improve segregation resistance and compaction ability. On the other hand, the water-cement ratio of 40%, which had the highest viscosity, yielded excellent segregation resistance but reduced compaction ability, indicating the importance of selecting appropriate mix proportions in consideration of the construction conditions.
- Keywords:
- Segregation resistance, Compaction ability, Tamping test, Ultrasonic wave propagation velocity, Viscosity, Passing ability
