钢纤维混凝土裂缝宽度影响系数试验探究

Experimental Research on the Influence Factor of Crack Width of Steel Fiber Reinforced Concrete

研究目的:现行规范中钢纤维混凝土裂缝宽度影响系数取值过于保守,由其制成的构件或结构应用于交通隧道工程中不具有较好的经济性,而规范规定其值宜通过试验确定。基于此,本文通过构件试验及数值试验,得到钢纤维混凝土裂缝宽度影响系数随裂缝宽度的变化曲线,结合可靠度及概率论,通过数据统计分析得到钢纤维混凝土裂缝宽度影响系数值。研究结论:(1)钢纤维能够有效降低混凝土构件裂缝宽度,相对于同一配筋形式下的钢筋混凝土构件,裂缝宽度降低50%以上;(2)通过纯弯梁和偏压柱的构件试验及数值试验,计算得到钢纤维混凝土裂缝宽度影响系数为0. 42;(3)裂缝宽度影响系数随构件横截面尺寸的增大而增大、随裂缝宽度的增大而减小;(4)本研究成果可为钢纤维混凝土裂缝宽度影响系数的进一步研究提供借鉴。

Research purposes: The influence coefficient of the crack width of steel fiber reinforced concrete is too conservative in the current code. The component or structure made of it has no good economy in the traffic tunnel engineering, and the standard should be determined through the test. By means of the component test and numerical test, the curves of the influence factor of crack width of steel fiber reinforced concrete varying with crack width were got, combining the theory of reliability and probability, the value of influence factor of crack width of steel fiber reinforced concrete was obtained through data analysis. Research conclusions:(1) Steel fiber can effectively reduce the crack width of concrete members. Compared with the reinforced concrete members with the same reinforcement, the crack width is reduced by more than 50%.(2) The influence coefficient of steel fiber reinforced concrete crack width is 0.42, by the means of component test and numerical test of pure bending beam and eccentrically loaded column.(3) The influence coefficient of crack width increases with the increase of cross section size and decreases with the increase of crack width.(4) The research results can provide reference for further study on the influence coefficient of crack width of steel fiber reinforced concrete.