塑钢纤维增强轻骨料混凝土与钢筋粘结性能试验研究

摘要

Through pull-out test to steel bars attached strain gages inside,the single and multiple factors effect of HPP fiber dosage,concrete matrix strength and lightweight aggregate cylinder pressure strength to the bond performance between steel bar and HPP fiber reinforced lightweight aggregate concrete was analyzed.The results of pull-out test with different influences show that:reinforced function of HPP fiber for different water cement ratio specimens show different strengthening rules,for high w/c specimens,the ultimate bond strength increases with increasing of fiber content;for low w/c specimens,fiber reinforced function decreases with increasing fiber content;increase the concrete strength grade,the ultimate bond strength,and bond strength corresponding to the initial slip of free end increase,the ultimate bond strength corresponding to the free end displacement decreases;reduce lightweight aggregate strength,the HPP fiber reinforced lightweight aggregate concrete compressive strength,splitting tensile strength and ultimate bond strength decreases;lightweight aggregate cylinder pressure strength affected the ultimate bond strength most through orthogonal experiments.%通过对内贴应变片钢筋的直接拔出试验,分析塑钢纤维掺量、基体强度以及轻骨料筒压强度等单一及多重因素对纤维增强轻骨料混凝土与钢筋间粘结强度和粘结应力分布的影响,得出三种影响因素对试件粘结性能的影响规律,并通过正交试验分析三种因素对试件粘结性能的影响程度.试验结果表明:塑钢纤维掺量对不同水灰比试件表现出不同的增强规律,对于水灰比大的试件,其极限粘结强度随纤维掺量增加而增大;对于水灰比小的试件,纤维增强作用随纤维掺量增大而减小;混凝土基体强度等级越高,试件极限粘结强度、自由端初始滑移对应粘结强度越高,峰值滑移减小;轻骨料筒压强度降低,纤维增强轻骨料混凝土的抗压强度、劈拉强度及基体与钢筋的极限粘结强度均会降低;通过正交试验得出轻骨料筒压强度对试件极限粘结强度影响程度最大.