KONG Xiang-zhi, JI Guo-jin, LIU Yan-xia, LIU Chen-xia (Department of Structures and Materials, IWHR, Beijing 100038, China)

Abstract: The changes of concrete permeability and the mechanical properties of hydraulic concrete due to leakage dissolution, as well as the Ca 2 + concentration and pH value changes of the leakage water are studied in this paper. The results show that hydraulic concrete with good vibration and curing has a high resistance to leakage dissolution and the self-healing property. In the early leakage period, there is a linear relationship between leaching amount of Ca 2+ and the amount of seepage water, and also the Ca 2+ concentration, pH value and electric conductivity of seepage water are changing in a stable range. Linear fitting can be performed between the performance degradation of hydraulic concrete and Ca (OH) 2 leaching percentage. With the calcium hydroxide leaching amount of 5.13%, the compressive strength, splitting tensile strength and elastic modulus decrease by 2.24%, 7.94% and 4.10%, respectively, of which the splitting tensile strength is the most sensitive property.

Key words: hydraulic concrete; leakage dissolution; performance degradation; permeability; self-healing

Published in: Journal of China Institute of Water Resources and Hydropower Research (Vol. 10 No. 1 March. 2012)