Abstract
Four types of concrete were placed on a reinforced concrete structure, and behaviours of cracks which had occured in the structure were examined for a long time. Normal concrete with plasticizer, concrete containing shrinkage reducing agent, concrete containing both shrinkage reducing agent and expansive admixture, and superplasticized concrete were selected for this experiment. Relations between the effects of reducing drying shrinkage by using these admixtures and cracks which occured in external walls of the structure were investigated for 3 years after placing. As the results, it was found that cracks could be reduced greatly by using shrinkage reducing agent. These results are discussed on this paper.
