Effect of pre-wetted light-weight aggregate on internal relative humidity and autogenous shrinkage of concrete

Abstract

This research indicates that the gradient of internal relative humidity (IRH) decreases rapidly within 1-day curing age in HPC. The amount of water imported by pre-wetted light-weight aggregate can regulate IRH of concrete. By importing a proper amount of water, the process of the decline of IRH can be delayed and the autogenous shrinkage can be reduced. The relationship among the amount of water imported by pre-wetted lightweight aggregate, IRH and AS was established. The result provides a new method of reducing early AS and enhancing early cracking resistance of HPC.

Keywords

autogenous shrinkage / pre-wetted lightweight aggregate / internal relative humidity / high performance concrete

References

[1] Lura P. Autogenous Deformation and Internal Curing of Concrete, 2003 Delft: Delft University Press.

[2] Shenghua Xu, Zhengwu Jiang. Research on Relative Humidity and Autogenous Shrinkage of High Performance Concrete. Journal of Chongqing Jianzhu University, 2004, 26(2): 21-24.

[3] Bentur A, Igarashi Shin-ichi, Kovler K. Prevention of Autogenous Shrinkage in High-strength Concrete by Internal Curing Using Wet Lightweight Aggregates. Cement and Concrete Research, 2001, 31: 1587-1591.

[4] Jiang Yaqian, Xu Zhongzi, Jianlin Wu. Internal Curing Effect of Soaked Lightweight Aggregate on High Performance Concrete. Concrete and Cement Products, 2003, 5: 13-15.

[5] Hu Shuguang, Wang Fazhou, Ding Qingjun. The Influence of Water Absorption and Pre-wetted Method of Lightweight Aggregate on the Workability of Concrete.Journal of Huazhong University of Science and Technology (Urban Science), 2002 (2): l-4(in Chinese)