冻融条件下钢纤维混凝土与老混凝土粘结面的劈拉性能

通过对105块100mm×100mm×100mm钢纤维混凝土与老混凝土立方体粘结试块快速冻融后的劈拉试验,探讨冻融循环次数、钢纤维体积率等因素对新老混凝土粘结性能的影响。结果表明,钢纤维混凝土与老混凝土粘结劈拉强度随冻融次数增加而下降、随钢纤维体积率的增加有一定程度提高。最后,建立了考虑老混凝土劈拉强度、冻融循环次数和钢纤维体积率影响的钢纤维混凝土与普通老混凝土粘结劈拉强度的计算模式。

THE SPLITTING TENSILE BEHAVIOR OF THE BONDING INTERFACE BETWEEN FRESH STEEL FIBER CONCRETE AND OLD CONCRETE UNDER FREEZE-THAW

By the splitting tensile strength experiments on the specimens with the dimension of 100mm×100mm×100mm,it is explored that the influence of the number of freeze-thaw cycle and steel fiber volume fraction upon the splitting tensile behavior of the bonding interface between fresh steel fiber concrete and old concrete through quickly freeze-thaw testing.The result demonstrates that the splitting tensile strength of the bonding specimen declines with the escalating of the freeze-thaw cycle's number and the strength aggrandizes a certain extent with the increasing of the steel fiber volume fraction.At last,the calculating formula of the splitting tensile strength of the bonding interface is established,which considers the influence of old concrete 's splitting tensile strength,number of freeze-thaw cycle and steel fiber volume fraction.