自密实混凝土无腹筋梁抗剪性能

为研究自密实混凝土无腹筋梁的抗剪性能和裂缝开展形态，进行了集中荷载作用下12根无腹筋钢筋混凝土简支梁（8根自密实混凝土和4根普通混凝土）的剪切破坏试验，变量为混凝土强度和剪跨比。探讨了《混凝土结构设计规范》（GB 50010―2010）、Zsutty拟合公式、美国规范（ACI318-11）抗剪承载力计算公式对自密实混凝土无腹筋梁抗剪承载力计算的适用性和准确性。收集了在集中荷载作用下的130根自密实混凝土和798根普通混凝土矩形截面无腹筋梁剪切破坏试验数据，将自密实混凝土和普通混凝土无腹筋梁抗剪承载力进行了对比。结果表明：自密实混凝土梁和普通混凝土梁的裂缝发展、破坏形态大致相同，自密实混凝土梁斜裂缝断面更为光滑；Zsutty拟合式计算结果与本文试验结果最接近；GB 50010—2010计算结果与本文试验结果也比较吻合，但偏于不安全；美国规范ACI 318-11计算公式偏差较大；自密实混凝土梁受剪承载力略低于普通混凝土梁。

Shear behaviour of self-compacting concrete beams without shear reinforcement

An experimental investigation was conducted to study the shear strength and cracking behavior of beams made with self-consolidating concrete (SCC) as well as normal concrete (NC). A total of 12 flexurally reinforced concrete beams which consist of 8 beams with self-compacting concrete and 4 beams with normal concrete, with no shear reinforcement, were tested under mid-span concentrated load until shear failure occurred. The main variables in the test are concrete strength and shear span ratio. While, based on the test data in this study, several shear strength models:GB 50010-2010, Zsutty'' formula, ACI 318-11 were analyzed and compared. The shear experimental test data of 130 self-consolidating concrete and 798 normal concrete simply-supported rectangular cross-section beams without web reinforcement were collected to compare the shear capacity between SCC and NC beams. The results show that:In terms of crack morphology, crack progression, the behavior of the SCC and CC beams is virtually identical, and the inclined section of SCC beams are more smooth; The calculated results of Zsutty'' fit are closest to the experimental results; the results of GB 50010-2010 are also in good agreement, but are not safe; the deviation of ACI 318-11 is larger; and the ultimate shear strength of SCC beams is found to be slightly lower than the NC beams.