RESEARCH ON THE IMPACT OF FIBER ON THE WIDTH AND PERMEABILITY OF CONCRETE CRACKS: BASED ON RESPONSE SURFACE METHODOLOGY

In order to study the impact of polypropylene long fiber, steel fiber, and the polypropylene short fiber on the permeability of cracked concrete, a new type of infiltration device was used and a response surface model is applied to investigate the effect of different mixing dose, fiber types, and hybrid methods on impact of permeability of concrete with different crack widths. The results of the study show that: the permeability coefficient of single 60 kg/m(3) steel fiber is reduced by 95.7% than that of 30 kg/m(3). Polypropylene short fibers have little effect on bridging structural cracks, and have little effect on permeability. Steel fiber and Macro-PP can effectively limit the expansion of cracks and reduce the permeability of concrete after cracking.