| "The repair of deteriorated concrete structures is indispensable for their prolonged utilization. In Japan, many types of repair materials have been developed, some of which have already been used for the rehabilitation of concrete structures. However, the repair materials differ in their properties, especially with regard to theresistance to crack formation due to their shrinkage. This makes it difficult to select repair materials that can perform adequately for preventing shrinkage cracks. After the introduction of many types of repair materials, several experiments were proposed to investigate their characteristics in terms of shrinkage. While the shrinkage properties were considered in these experiments, the restraint conditions caused by the parent concrete were not dealt with. The importance of restraint conditions in the tests for repair materials should be reemphasized for their practical application to existing structures. This paper presents the evaluation method for the shrinkage properties of repair materials with regard to the restraint conditions caused by the parent concrete. In addition, this evaluation method is applied to three different types of repair material specimens, such as polymer cement mortar, cement mortar, and lightweight polymer cement mortar. Moreover, the properties of repair materials required for preventing the cracks induced by shrinkage are discussed." |
