纤维橡胶砂浆的力学性能与砌体轴压试验

为提高橡胶砂浆的力学性能和适用性,通过单掺聚乙烯醇(PVA)纤维或钢纤维、复掺PVA-钢纤维对橡胶砂浆进行改性,探讨其对超声波传播速度、抗折强度和抗压强度的影响。将普通水泥砂浆、20%橡胶砂浆、复掺PVA-钢纤维橡胶砂浆分别与环保压缩砖结合制作砌体,通过试验研究轴心抗压强度和弹性模量。结果表明:掺入PVA纤维或复掺PVA-钢纤维降低了超声波在橡胶砂浆中的传播速度; 掺入PVA纤维或钢纤维提高了橡胶砂浆的抗折强度; 复掺一定量的PVA纤维和钢纤维能有效提高橡胶砂浆的抗压强度; 20%橡胶砂浆的抗压强度比普通水泥砂浆降低了46%,对应砌体的破坏荷载降低了12.8%; 复掺PVA-钢纤维橡胶砂浆的抗压强度比20%橡胶砂浆提高了14.9%,对应砌体的开裂荷载和破坏荷载分别提高了63.4%和4.5%; 掺入适量PVA纤维和钢纤维能改善橡胶砂浆的强度明显低于普通水泥砂浆的缺点,将复掺PVA-钢纤维橡胶砂浆应用于砌体工程能改善结构的隔音性,延缓试件的开裂,提高橡胶砂浆砌体的抗压强度。

Mechanical properties of fiber rubber mortar and axial compression test of masonry

In order to improve the mechanical properties and applicability of rubber mortar, the rubber mortar was modified by single-doped polyvinyl alcohol(PVA)fiber or steel fiber, and PVA-steel fiber, then the influences on ultrasonic propagation speed, flexural strength, and compressive strength were discussed. Ordinary cement mortar, 20% rubber mortar and PVA-steel fiber rubber mortar were combined with environmentally friendly compressed bricks to make masonry, and the axial compressive strength and elastic modulus were studied. The results show that adding PVA fiber or PVA-steel fiber reduces the propagation speed of ultrasonic waves in rubber mortar. Adding PVA fiber or steel fiber improves the flexural strength of rubber mortar. A certain amount of PVA fiber and steel fiber can effectively improve the compressive strength of rubber mortar. The compressive strength of 20% rubber mortar is 46% lower than that of ordinary cement mortar, and the failure load of masonry is reduced by 12.8%. The compressive strength of PVA-steel fiber rubber mortar is 14.9% higher than that of 20% rubber mortar, and the cracking load and failure load of the corresponding masonry are increased by 63.4% and 4.5% respectively. Adding a proper amount of PVA fiber and steel fiber can improve the strength of rubber mortar, which is obviously lower than ordinary cement mortar. Applying compounded PVA-steel fiber rubber mortar to masonry engineering can improve the sound insulation of the structure, delay the cracking of specimen, and improve the compressive strength of the rubber mortar masonry.