层布式混杂纤维混凝土冻融损伤研究

为研究层布式混杂纤维混凝土在冻融疲劳作用下的损伤演变规律,建立一混凝土抗冻劣化的损伤演变数学模型,在试验的基础上回归出普通混凝土和层布式混杂纤维混凝土的冻融损伤演化方程.结果表明,LHFRC和OC的初劣点值相同,且在劣化初始阶段具有相同的损伤演变方程;在劣化扩展阶段,LHFRC和OC均具有幂函数形式的损伤演变方程,但LHFRF损伤变量小于同期的OC,钢纤维和聚丙烯纤维有效地抑制了其内部损伤发展.

Freeze-Thaw Cycling Damage of Layered Hybrid Fiber Reinforced Concrete

A damage model has been formulated for the freeze-thaw degradation of layered hybrid fiber reinforced concrete (LHFRC). This model is based on the least squares theory and a damage variable D. The D is the loss rate of dynamic modulus of elasticity of concrete, which was used to describe the damage process of concrete subject to freeze-thaw cycles. Degradation equations for the LHFRC and plain concrete (PC) have been accurately regressed with the experimental data, which are identical in the initial phase and different in the damage propagation phase. The D of LHFRC is smaller than that of PC at the same time. Furthermore, the frost resistance of LHFRC is better than that of PC due to steel fibers and polypropylene fibers have effectively retarded the degradation of concrete. Steel fibers and polypropylene fibers are important factors that strongly influence the frost resistance of concrete.