平面应力状态下混凝土强度的软化

变换施加于钢筋砼平板试件水平及垂直方向拉力与压力的比值以及钢筋的配置方向,使平板内产生不同的应力状态、用于研究砼强度的软化性能。研究表明:在二向拉压力作用下,钢筋砼平板中的砼不仅主应力方向的抗压强度降低,而且抗拉强度也降低,即存在砼强度软化现象。同一砼和配筋率情况下,砼强度的降低程度与配筋角度及施加于试件两向的拉压应力比有关,而与加載路径无关。通过分析,提出了砼抗压和抗拉的强度软化计算公式。

SOFTENING OF CONCRETE STRENGTH UNDER PLANE STRESS

In this paper, the softening behavior of concrete strength is investigated by variating the ratio of tensile and compressive forces imposed on nine R. C. plate specimens in the horizontal and vertical directions, as well as the directions of reinforcing bars, in order to develop different stress states in plate specimens. The experiments show that the compressive strength of R. C. plates in the direction of principal stress decreases under tension and compression in two perpendicular directions, and concrete tensile strength decreases as well. These can be explained as the softening of concrete strength. Under the conditions of the same concrete and reinforcement ratio of specimens, the degree of concrete strength decrease is related to reinforcement angle and ratio of tensile-compressive stress imposed on the plate specimens, and it has nothing to do with the loading path. Based on the experiment and analysis, calcalating formulae of the softening of concrete compressive strength and tensile strength are presented.