Effect of pore structure on shear resistance and chloride transport of macro-synthetic fiber reinforced concrete

This study proposes a method for the quantitative characterization of the complexity and uniformity of pore structure, and explores the effect of macro-synthetic fiber inclusion on the shear resistance and chloride transport of concrete from the perspective of pore structure. First, the shear capacity and chloride migration coefficient of normal concrete and macro-synthetic fiber reinforced concrete with fiber content of 3, 4.5, 6, and 9 kg/m3 were tested. Next, the porosity and pore size distribution were determined using the Rapidair 457 pore structure analyzer. The complexity of the pore structure was quantified using the fractal dimension calculated from the pore structure scans. The uniformity of spatial distribution of pores was quantified by the standard deviation of pore frequency. The results showed that increasing the fiber content increased the shear resistance and chloride transport of concrete while increasing the complexity and uniformity of pore structure. High-fidelity correlations between shear resistance and pore structure uniformity, chloride transport and pore structure complexity were established. This study will promote the fundamental understanding of concrete pore structure and properties for the development of high-performance fiber reinforced concrete.