混掺纤维RPC增韧特性试验研究

发布时间：2018-10-21 09:19

【摘要】：采用钢纤维与粗聚烯烃纤维或细聚乙烯醇纤维混掺技术,制备了新型超高强度活性粉末混凝土(RPC),以改善RPC的韧性及脆性;由弯曲试验测其荷载-位移曲线,分析了纤维品种、掺量变化对新型RPC韧性的影响规律,并对比了在胶凝材料中添加超细水泥或硅灰所制备的RPC的韧性.结果表明:混掺纤维RPC的荷载-位移曲线具有二次硬化特征;混掺纤维RPC的韧性指标明显高于单掺钢纤维RPC,以1%钢纤维体积分数与9kg/m3粗聚烯烃纤维混掺所制备的超细水泥RPC韧性指标T(7)比单掺钢纤维时提高70%;从经济性看,以1%钢纤维体积分数与粗聚烯烃纤维或细聚乙烯醇纤维混掺对RPC增韧效果更优;当钢纤维体积分数为2%时,细聚乙烯醇纤维掺量不宜高于9kg/m3;超细水泥RPC韧性优于硅灰RPC试件.
[Abstract]:A new type of ultra-high strength reactive powder concrete (RPC),) was prepared by mixing steel fiber with coarse polyolefin fiber or fine polyvinyl alcohol fiber to improve the toughness and brittleness of RPC. The effect of the content of RPC on the toughness of the new RPC was studied. The toughness of RPC prepared by adding ultrafine cement or silica fume to the cementing material was compared. The results show that the load-displacement curve of RPC mixed with fiber has the characteristic of quadratic hardening. The toughness index of blended fiber RPC is obviously higher than that of single doped steel fiber RPC, with 1% volume fraction of steel fiber and 9kg/m3 coarse polyolefin fiber. The toughness index T _ (7) of superfine cement prepared by blending with 9kg/m3 coarse polyolefin fiber is 70% higher than that of single doped steel fiber. Blending 1% steel fiber volume fraction with coarse polyolefin fiber or fine polyvinyl alcohol fiber has better toughening effect on RPC, when the volume fraction of steel fiber is 2, the volume fraction of fine polyvinyl alcohol fiber should not be higher than 9 kg / m3; the toughness of ultrafine cement RPC is better than that of silica fume RPC specimen.
【作者单位】：北京工业大学城市与工程安全减灾省部共建教育部重点实验室;
【基金】：国家自然科学基金资助项目(51378032) 北京市自然科学基金资助项目(8142005)
【分类号】：TU528.572

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