纤维增强轻质自密实混凝土梁力学性能试验研究  

Experimental Study on Mechanical Property of Fiber⁃reinforced Lightweight Self⁃compacting Concrete Beam

作　　者：曾伟波 ZENG Weibo(Public Works Department in Bao’an District of Shenzhen,Shenzhen,Guangdong 518100,China)

机构地区：[1]深圳市宝安区建筑工务署,广东深圳518100

出　　处：《施工技术(中英文)》2025年第3期137-142,共6页Construction Technology

摘　　要：仅使用自密实混凝土制作对照梁,在此基础上采用轻质膨胀黏土作为粗骨料替代材料制作轻质自密实混凝土梁,进一步添加钢纤维和混合纤维(钢纤维+聚丙烯纤维)制作纤维增强轻质自密实混凝土梁,开展纤维增强轻质自密实混凝土梁力学性能试验研究。轻质膨胀黏土替代率分别为50%,100%,纤维体积比为1%,通过试验研究得到不同混凝土梁荷载-跨中挠度关系,比较开裂荷载、极限荷载、裂缝宽度等。研究结果表明,与对照梁相比,轻质膨胀黏土骨料部分和完全替代传统骨料的无纤维梁极限荷载分别降低41.25%,37.75%;钢纤维可在混凝土中有效承担拉应力,从而减少混凝土裂缝的发展和扩展,提升了混凝土梁极限荷载,改善了混凝土梁裂后行为;钢纤维可与聚丙烯纤维协同作用,使混合纤维增强轻质自密实混凝土梁能够更好地分散应力,从而提高整体性能和耐久性。Only self⁃compacting concrete was used to make the control beam.On this basis,lightweight expanded clay was adopted as the coarse aggregate replacement material to make lightweight self⁃compacting concrete beams.Further,steel fibers and hybrid fibers(steel fibers+polypropylene fibers)were added to make fiber⁃reinforced lightweight self⁃compacting concrete beams.Mechanical performance tests of the fiber⁃reinforced lightweight self⁃compacting concrete beams were carried out.The replacement rates of lightweight expanded clay were 50%and 100%,and the fiber volume ratio was 1%.Through the tests,the load and mid⁃span deflection relationships of different concrete beams were obtained,and the cracking load,ultimate load,and crack width were compared.The research results show that compared with the control beams,the ultimate loads of the beams with lightweight expanded clay aggregate partially and completely replacing traditional aggregates without fibers decreased by 41.25%and 37.75%respectively.Steel fibers can effectively bear tensile stress in concrete,thereby reducing the development and expansion of concrete cracks,increasing the ultimate load of concrete beams,and improving the post⁃cracking behavior of concrete beams.Steel fibers can work in synergy with polypropylene fibers,enabling the hybrid fiber⁃reinforced lightweight self⁃compacting concrete beams to better disperse stress and thereby enhance overall performance and durability.

关 键 词：混凝土 钢纤维 力学性能 试验 

分 类 号：TU528[建筑科学—建筑技术科学]