PE纤维与细橡胶颗粒对泡沫混凝土弯曲韧性的影响

Effects of PE Fiber and Fine Rubber Particles on Flexural Toughness of Foam Concrete

研究了聚乙烯(PE)纤维及其与细橡胶颗粒复掺对泡沫混凝土弯曲破坏模式、峰值强度、能量吸收特性和弯曲韧性的影响,并结合孔结构分析和微观形貌观察探究了其作用机理.结果表明:PE纤维使泡沫混凝土出现多缝开裂模式,显著提升了其峰值强度、能量吸收能力和弯曲韧性;复掺细橡胶颗粒可以进一步提升泡沫混凝土试件的比能量吸收和弯曲韧性;掺入PE纤维可以降低泡沫混凝土的平均孔径;复掺细橡胶颗粒导致泡沫混凝土试件的平均孔径增大,联通孔增多,对其峰值强度有不利影响;PE纤维及细橡胶颗粒提升泡沫混凝土弯曲韧性的主要原因在于其削弱了裂纹尖端的应力集中,同时增强了能量耗散作用.

The effects of polyethylene(PE)fiber and its combinayion with fine rubber particles on the flexural damage mode,peak strength,energy absorption characteristics,and flexural toughness of foam concrete were investigated,and the mechanism of action was explored by combining pore structure analysis with microscopic morphological observation.The results show that PE fibers cause the multiple cracking modes of the foam concrete and significantly improve the peak strength,energy absorption capacity,and flexural toughness of the foam concrete specimens.Combining with fine rubber particles can further enhance the specific energy absorption and flexural toughness of the foam concrete specimens.The incorporation of PE fibers could reduce the average pore size of the foam concrete.Combining with fine rubber particles leads to an increase in the average pore size and the number of coupled pores,which has a negative impact on the peak strength of the foam concrete specimens.The main reasons for PE fiber and combination with fine rubber particles to enhance the flexural toughness of foam concrete are their weakening of stress concentration at the crack tip and enhancement of energy dissipation.