采用浓度为0. 5 mol/ L 的硝酸溶液对含浇筑层面的混凝土试件进行加速溶蚀试验,研究了层面劈裂抗拉强度、溶蚀深度和钙离子累计相对溶蚀量等3 种评价指标的时变规律,以及层间间歇时间和凿毛处理对抗溶蚀性的影响,据此建立了层面劈裂抗拉强度的两种预测模型。结果表明:层面劈裂抗拉强度随溶蚀时间平方根和钙离子累计相对溶蚀量的增大而线性减小,间歇时间和凿毛处理对所拟合曲线的斜率影响较小;层面溶蚀程度随间歇时间的延长而增大,间歇24 h 时层面溶蚀深度增加15%;间歇时间越长,凿毛处理对抗溶蚀性的提升效果越弱,以6 h 之内为最优;间歇时间12 h 以内,层面劈裂抗拉强度下降速度较快,12 h 时降幅为14. 6%,由此将导致浇筑层面的耐溶蚀年限缩减61%。
Accelerated dissolution tests were conducted for concrete specimens with pouring layer interface using nitric acid solution with the concentration of 0.5 mol/L. The evolution laws of three leaching evaluation indexes, which were the splitting tensile strength, leaching depth and cumulative relative leached calcium, and the effects of interval time and layer roughening on the leaching process were studied. Two prediction models were then established for the splitting tensile strength of the layer interface. The research results show that the splitting tensile strength has linear relationships with the square root of leaching duration and the cumulative relative leached calcium. The interval time and layer roughening mainly affect the initial value of strength and have little effect on the linear slopes. The leaching degree of layer interface increases with the interval time, in which the leaching depth of layer interface increases by 15% when the interval time comes up to 24 h. The reinforcement effect of layer roughening on leaching resistance decreases with the interval time, and 6 h is the optimum interval time. When the interval time is less than 12 h, the splitting tensile strength of layer interface decreases fast, and the decrease rate is 14.6% within 12 h, which can reduce the leaching resistance service life of the concrete layer interface by 61%.
王少伟,徐应莉,朱平华,等.溶蚀作用下混凝土层面劈裂抗拉强度试验研究[J].水利水电科技进展,2022,42(1):27-32.(WANG Shaowei, XU Yingli, ZHU Pinghu, et al. Experimental study on splitting tensile strength of concrete layer interface under dissolution effects[J]. Advances in Science and Technology of Water Resources,2022,42(1):27-32.(in Chinese))复制