CAJ | 학술논문

为研究不同粗合成纤维用量下活性粉末混凝土的抗弯韧性，采用四点弯曲试验对粗合成纤维用量分别为4．75，9．5，14．25，19 kg ? m -3的纤维活性粉末混凝土试件进行了研究，同时与不掺入纤维的素活性粉末混凝土进行了对比分析。结果表明：不掺入纤维的素活性粉末混凝土弯拉试件发生脆性破坏，试件一裂即断，未得到荷载-挠度曲线的下降段；而粗合成纤维掺入后能够提高活性粉末混凝土的韧性，使弯拉试件转变为明显的延性破坏，荷载-挠度曲线都可得到稳定的下降段，同时曲线还出现了二次强化现象，有2个峰值；随着粗合成纤维掺量的增加，弯拉试件荷载-挠度曲线的下降段愈加平缓，韧性指数增大；粗合成纤维掺量（体积分数）为1．0％～2．0％时，剩余强度在抗折强度的85％以上，此时粗合成纤维对裂后基体具有较强的阻裂能力，能够大大提高弯拉试件开裂后的韧性。
위연구불동조합성섬유용량하활성분말혼응토적항만인성，채용사점만곡시험대조합성섬유용량분별위4．75，9．5，14．25，19 kg ? m -3적섬유활성분말혼응토시건진행료연구，동시여불참입섬유적소활성분말혼응토진행료대비분석。결과표명：불참입섬유적소활성분말혼응토만랍시건발생취성파배，시건일렬즉단，미득도하재-뇨도곡선적하강단；이조합성섬유참입후능구제고활성분말혼응토적인성，사만랍시건전변위명현적연성파배，하재-뇨도곡선도가득도은정적하강단，동시곡선환출현료이차강화현상，유2개봉치；수착조합성섬유참량적증가，만랍시건하재-뇨도곡선적하강단유가평완，인성지수증대；조합성섬유참량（체적분수）위1．0％～2．0％시，잉여강도재항절강도적85％이상，차시조합성섬유대렬후기체구유교강적조렬능력，능구대대제고만랍시건개렬후적인성。
In order to evaluate the flexural toughness of synthetic macro-fiber reinforced reactive powder concrete ,beam specimens were tested under four points flexural method .The contents of synthetic macro-fiber were 4 .75 ,9 .5 ,14 .25 ,19 kg ? m - 3 ,respectively ,and plain reactive powder concrete specimens without fiber were analyzed in contrast .The results show that plain reactive powder concrete specimens without fiber are brittleness ,specimens breakdown when the crack is appeared ,and the descending branch of load-deflection curves cannot be collected . While the failure mode of specimens with synthetic macro-fiber is ductility and a steady descending branch of load-deflection curves is collected .At the same time ,the curves all have two peaks ,presenting the phenomenon of secondary reinforcement .This means that synthetic macro-fiber can improve the flexural toughness of reactive powder concrete .Descending branch of load-deflection curves is flatter and toughness index with the increasing of fiber content .The residual intensity is above 85% of flexural strength when the fiber content (volume fraction ) is 1 .0% -2 .0% , which indicates that synthetic macro-fiber has excellent crack resistance ,and can improve the ductility of bending-tension specimens after cracking .