聚乙烯醇改性水泥砂浆的断裂性能

Fracture Properties of Polyvinyl Alcohol Modified Cement Mortar

摘要:

通过三点弯曲法测试了聚乙烯醇(PVA)改性水泥砂浆的断裂性能，采用双K断裂模型分析了PVA掺量对改性水泥砂浆断裂参数的影响.结果表明：PVA改性水泥砂浆的裂缝口张开位移和裂缝尖端张开位移均随PVA掺量的增加而增大；当PVA掺量为10%(质量分数)时，改性水泥砂浆具有最佳失稳断裂韧度和起裂断裂韧度，较普通水泥砂浆分别提高3831%和4082%；PVA改性水泥砂浆的各项断裂参数均与PVA掺量呈二次抛物曲线变化规律.

Abstract:

Effect of polyvinyl alcohol(PVA) on the fracture properties of cement mortar was investigated. The fracture parameters such as unstable fracture toughness and initial fracture toughness were obtained through double K fracture model. Results show that the critical crack mouth opening displacement, ultimate crack mouth opening displacement and crack tip opening displacement of PVA modified cement mortar increase with the increase of PVA content. For the unstable and initiation fracture toughness, the optimum PVA content in mortar is 10%(by mass), it will be increased by 3831% and 4082% as compared with the control. Additionally, the basic fracture parameters and corresponding double K fracture parameters of cement mortar beam are showing a significant quadratic parabolic curve variation with PVA content.