基于多尺度试验的聚丙烯纤维泡沫混凝土性能与破坏机制研究OACHSSCD

An experimental investigation was conducted on polypropylene fiber-reinforced foam concrete with var-ying fiber volume fractions(0,0.24%,0.48%,0.72%)to evaluate its fluidity,water absorption,static uniax-ial compression performance,and static splitting tensile strength.A multi-scale analysis integrating macroscopic failure patterns and pore structure characterization under optical microscopy was performed to elucidate the influ-ence of polypropylene fibers on the mechanical properties and failure mechanisms of foam concrete.The results indicate that the water absorption rate first decreases and then increases with the fiber content.An appropriate amount of fibers(0.48%)can significantly enhance the compressive strength and tensile strength of the speci-mens.And the internal fibers inhibit crack propagation through bridging,causing the failure mode to change from brittle crushing type to shear slip type,showing a significant increase in ductility.However,excessive fibers(0.72%)will reduce fluidity and cause local disorder of pore structure,with limited improvement in me-chanical properties.Optical microscopic observation further reveals that fibers with a reasonable dosage can opti-mize pore distribution and enhance overall density and toughness.