煤矸石混凝土梁受剪性能试验研究

Experimental study on shear behavior of coal gangue concrete beams

为研究煤矸石混凝土梁受剪性能,对9个煤矸石混凝土梁和1个普通混凝土对照梁进行了受剪试验,分析了煤矸石混凝土梁斜截面破坏形态、开裂荷载和受剪承载力。结果表明:煤矸石混凝土梁和普通混凝土梁受剪破坏形态相似;在同一荷载等级下,煤矸石混凝土梁试件跨中挠度随煤矸石取代率的增加而增大,而达到各试件极限荷载时其挠度值相差不大;斜向开裂荷载随煤矸石取代率的增加而减小,煤矸石混凝土梁较普通混凝土梁降低了19.6%~31.5%;受剪承载力随煤矸石取代率的增加也有降低趋势,煤矸石混凝土梁较普通混凝土梁降低了8.9%~24.0%;此外,剪跨比和配箍率对煤矸石混凝土梁受剪性能的影响与普通混凝土梁相似,受剪承载力随剪跨比的增加而减小,随配箍率的增加而增加;煤矸石混凝土梁受剪承载力计算可采用GB 50010—2010《混凝土结构设计规范》中公式,且计算结果有一定的安全储备。

In order to study the shear performance of coal gangue concrete beams, nine coal gangue concrete beams and one ordinary concrete beam were tested for shear performance. The morphology of the inclined section of the gangue concrete beams, the cracking load of the inclined section and the shear bearing capacity were studied. The results show that the gangue concrete beam and the ordinary concrete beam have similar shear failure modes. Under the same load level, the mid-span deflections of the test specimens increase with the increase of replacement ratio of gangue, but they are close at the ultimate loads. The diagonal cracking load of specimens decreases with the increase of the coal gangue replacement ratio and it is reduced by 19.6%-31.5% compared with that of the ordinary concrete beam. The shear capacity of the test specimens tends to decrease with the increase of the replacement ratio of coal gangue, and it is reduced by 8.9%-24.0% compared with that of the ordinary concrete beam. The influences of shear span ratio and the stirrup ratio of coal gangue concrete beams are similar to those of ordinary concrete beams. The shear capacity decreases with the increase of shear span ratio and increases with the increase of stirrup ratio. The shear bearing capacity of gangue concrete beams can be calculated according to the formula stipulated in GB 50010—2010‘Code for design of concrete structure’.