Experimental Verification of Chemical Admixture to Reduce Stiffness of Concrete

In this paper, the phenomenon in which the fluidity drops significantly once the concrete, which is a problem in the construction work, is called “stiffness”, and the hypothesis of the occurrence mechanism was hypothesized based on a microscopic image of cement paste. Then, author developed a chemical admixture (stiffness reducing agent) that suppresses the aggregation of cement particles and verified the effect through various tests. In the verification test, author tried to quantify the stiffness of concrete by a simple test called the vane shear test. Also, through various construction performance tests, author confirmed the possibility of stiffness affecting the construction work.