橡胶细集料水泥砂浆基本性能研究

本文研究了橡胶细集料水泥砂浆的基本性能。试验表明橡胶细集料水泥砂浆的抗压强度及抗折强度明显受橡胶细集料掺量的影响。在橡胶细集料的掺量水平大于150kg/m3时,其28天立方抗压强度较普通砂浆降低30%或更多,抗折强度降低则超过20%。但同时发现该掺量水平下砂浆的应力应变特性与普通水泥砂浆相比存在显著不同,其抗折状态下极限拉应变可高达4600×10-6,极限轴压应变超过6000×10-6,凸现了其优越的变形能力,也预示着橡胶细集料水泥砂浆在能量吸收方面的潜力。试验中还发现橡胶细集料水泥砂浆的破坏模式与普通砂浆的脆性破坏模式相比较截然不同,表现出一定的延性破坏特征,由于橡胶细集料的掺入可以明显阻碍裂缝的开展,因此,橡胶细集料水泥砂浆试件能够经历反复加荷破坏过程而仍具有一定承载能力,表现出很高的延性。

Research in the fundamental characteristics of crumb rubber mortar

The article presents an experimental study on crumb rubber mortar (CRM).The crumb rubber takes about 15% in volume in CRM.The test results show a noticeable reduction,in comparison to controlled cement motar,in both compressive strength and flexural strength by as much as 20% or even higher.However,it is observed that the ultimate tensile (flexural) failure strain for CRM can reach 0.46%,far exceeding that of controlled cement motor.The similar observation is also made for energy absorption of CRM.The failure mode for CRM exhibits a gradual yielding pattern,which is often seen in plasticity,and deviates from the typical brittle fracture phenomenon as observed for controlled cement mortar.What interesting to quite a degree is that most specimens remain almost intact after they are firstly yielded under compressive strength,and continue to be able to bear a second loading circle,or so forth.It appears that CRM presents some new characteristics that may provide preferable engineering applications,yet with more studies are needed for further exploration.