混凝土孔结构与强度关系模型研究

Relationship modeling of pore structure and strength of concrete

研究了混凝土孔隙对强度的影响规律.结合混凝土材料科学、断裂力学的相关研究理论,分析了混凝土孔隙对弹性模量和断裂表面能的影响,对Griffith断裂理论进行了修正,进而提出了混凝土孔结构复合体模型.该模型不仅考虑了孔隙率对混凝土强度的影响,还考虑了孔径分布的影响,并对模型的断裂过程进行了分析.程序计算结果表明,计算强度与试验强度有较高的相关性,通过在模型中引入水泥质量分数对基体强度的影响能够使强度模型应用于不同水灰质量比混凝土孔结构的研究.

This work applied material science and fracture mechanics of concrete to study the influence of concrete pore structure on concrete strength. Analysis results of the influence of porosity on surface energy and elasticity modulus, and the fixed Griffith fracture theory were applied to set up the compound-body model of pore structure. This model considers the influences of both porosity and pore size distribution.Through analyzing the fracture process and compiling the procedure, it was found that the theoretical strength approximated the calculated strength. Introducing the influence of cement content on the strength of matrices into the model enables the strength model to be applicable to different water to concrete mass ratio. The results show that the consideration of water to concrete mass ratio expands the application range of the model.