C30钢纤维混凝土劈拉强度尺寸效应研究

Size Effect Study of Splitting Tensile Strength of C30 Steel Fiber Reinforced Concrete

为了研究C30钢纤维混凝土劈拉强度尺寸效应规律,制作边长为100、150、200mm,钢纤维体积率为0%、0.75%、1.5%的钢纤维混凝土立方体试件,试件在标准条件下养护7、28d,进行劈拉强度试验。在Bazant混凝土强度尺寸效应律的基础上,提出C30钢纤维混凝土劈拉强度尺寸效应计算公式,并得出不同尺寸试件之间的劈拉强度尺寸效应换算系数值。结果表明,钢纤维混凝土立方体尺寸越大,劈拉强度越低,存在尺寸效应。本文建立的钢纤维混凝土尺寸效应计算公式与试验数据吻合良好,能够较好地预测在不同钢纤维体积率及不同试件尺寸下的钢纤维混凝土试件的劈拉强度。

In order to study the size effect of splitting tensile strength of C30steel fiber reinforced concrete,a steel fiber reinforced concrete cube specimen with side length of100,150,200mm and steel fiber volume fraction of0%,0.75%and1.5%was fabricated.This specimen were cured under standard conditions for7days and28days,and the splitting tensile strength test was carried out.Based on the size effect law of Bazant concrete strength,the size effect formula of splitting tensile strength of C30steel fiber reinforced concrete was put forward,and the size conversion factor value of splitting tensile strength between different sizes of specimen was obtained.The results showed that the size of the steel fiber reinforced concrete cubes increased with the increase of the splitting tensile strength.The calculation formula of size effect of steel fiber reinforced concrete in this paper is in good agreement with the experimental data,and can predict the splitting tensile strength of steel fiber reinforced concrete specimens with different volume fraction of steel fiber and different specimen sizes.