论文部分内容阅读
本文根据混凝土Ⅰ型裂缝断裂能GF的测试原理和方法,采用偏直裂纹三点弯曲梁对陶粒混凝土Ⅰ-Ⅱ复合型断裂能G_F~(Ⅰ-Ⅱ)进行了实验测定,并与普通混凝土Ⅰ-Ⅱ复合型断裂能进行了对比。通过实验还研究了混凝土强度及K_Ⅰ/k_Ⅱ比值对陶粒混凝土Ⅰ-Ⅱ复合型断裂能G_F~(Ⅰ-Ⅱ)的影响。断裂能的概念是基于虚拟裂纹模型(Fictious Crack Model)建立起来的。以往的测试研究均是对Ⅰ型裂纹进行的,人们对Ⅰ型裂纹的断裂能的规律有了较多的认识。普遍认为断裂能的概念适合Ⅰ型裂纹,它反映了Ⅰ型裂纹的断裂特性。在实际的工程结构中,Ⅰ-Ⅱ复合型裂纹是更常见的情况。对于Ⅰ-Ⅱ复合型裂纹,G_F的概念能否适用以及以G_F为参数的一些数值计算模型能否适用于Ⅰ-Ⅱ复合型断裂等,这些都是人们想知道的。本文拟用偏裂纹三点弯曲梁探讨陶粒混凝土Ⅰ-Ⅱ复合型断裂。
According to the testing principle and method of fracture energy GF of concrete type I, the three-point bending beam of decentralized crack was used to measure the I-II composite fracture energy of ceramsite concrete G_F~(I-II), and it was compared with ordinary concrete. The I-II complex fracture energy was compared. The effect of the concrete strength and K_I/k_II ratio on the I_II complex fracture energy G_F~(I-II) of the ceramsite concrete has also been studied through experiments. The concept of fracture energy is based on the virtual crack model (Fictious Crack Model). The previous tests and researches were conducted on Type I cracks. People have more understanding of the law of the fracture energy of Type I cracks. It is generally believed that the concept of fracture energy is suitable for Type I cracks, which reflects the fracture characteristics of Type I cracks. In the actual engineering structure, I-II complex cracks are more common. For I-II composite cracks, whether the concept of G_F can be applied and whether some numerical calculation models with G_F as parameters can be applied to I-II composite fractures are all wanted by people. This paper intends to discuss the I-II composite type fractures of ceramsite concrete with deflection crack three-point bending beam.