中文摘要：

水泥基材料的抗开裂性能对于工程结构的安全性和耐久性至关重要。采用单一圆环法和组合圆环法研究了橡胶集料对水泥净浆抗开裂性能的影响。结果表明，随着橡胶积极掺量的增加，两种试验中圆环试件的开裂时间显著延长。而且，还发现在组合圆环试验中试件的开裂位置均发生在不掺加橡胶集料的区间范围内。分析表明，橡胶集料的加入不仅降低了材料的弹性模量，还增加了截面断裂时的耗能能力，这使得含有橡胶集料截面的抗开裂性能得以提高。

英文摘要：

Cracking resistance of cement based materials is critical for safety and durability of engineering structures.The influence of waste crumb rubber on the cracking resistance of cement paste specimens was investigated using single ring test and composite ring test. The results show that when crumb rubber is added,the cracking time of the specimens is delayed significantly in both two types of tests.In composite ring test,cracking always occurs in the segment of the specimen where crumb rubber is not added.The main reasons for the im-proved cracking resistance of the specimen can be attributed to the facts that the addition of crumb rubber decreases the elastic modulus of the specimen and improves the energy absorption of the sections.