Development of a smart material to mitigate thermal stress in early age concrete

Hydration heat of cement in massive concrete structures may cause significant thermal stress leading to cracking at early ages. In order to avoid such a thermal stress, a smart material for controlling the hydration heat has been developed in this study. The new material is composed of paraffin microcapsule containing a hydration-retarder agent. Once the temperature of concrete rises up to a certain value, which is specified by using different types of paraffin, the microcapsules melt and release the hydration-retarder agent. Hence, the temperature of concrete may be controlled under the specified value and thermal stress may be neglected. The applicability and performance of the proposed smart material are verified by a series of experimental studies and the experimental results are discussed.