混凝土与纤维混凝土的劈裂试验及损伤描述

Damage Description for Concrete and Fiber Concrete under Tensile Loads

描述工程材料在服役期间所受到的损伤,是评估其可靠度、耐久性等指标的重要依据.本文根据混凝土与纤维混凝土劈裂试验的结果,对一些损伤模型存在的问题进行的探讨认为:对于混凝土复合材料,卸载曲线的斜率受到粗骨料和纤维等因素的干扰,卸载刚度的衰减不能精确描述损伤的演化.并且,针对不同的极限状态,损伤描述应该有不同的形式.针对损伤对混凝土抗渗性能的影响问题,本文提出了损伤描述表达式.

In order to evaluate the durability and serviceability of concrete structure, it is necessary to analyze the damage evolution in the structure during service. Based on the results of spliting tests, some damage models are discussed in this paper. It is pointed out that, for composites such as concrete or fiber concrete, because the slope of its unloading curve is affected by the recovery force provided by fiber or coarse aggregate, the evolution of damage can′t be described with the degeneration of unloading rigidity precisely, and, for different ultimate conditions, the description of damage should be different. A damage expression is proposed to describe the damage evolution based on the concrete permeability.