不同最大粒径粗骨料和钢纤维掺量对再生混凝土抗冲击性能的影响  

Effects of maximum particle size coarse aggregates and steel fiber contents on impact resistance of recycled concrete

作　　者：夏冬桃 何国章 李彪 谢少军 付敏 XIA Dongtao;HE Guozhang;LI Biao;XIE Shaojun;FU Min(College of Civil Engineering and Environment,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,湖北武汉430068

出　　处：《混凝土》2022年第12期100-105,109,共7页Concrete

基　　金：国家自然科学基金(51108164,51608397)。

摘　　要：为了研究不同最大粒径粗骨料和钢纤维掺量对再生混凝土抗冲击性能的影响,采用改进的落锤冲击试验装置,制作了72个圆饼试件进行了抗冲击试验。配制了12种混凝土混合料,分别采用不同钢纤维体积掺量(0、0.8%、1.0%、1.2%)和不同最大粒径再生粗骨料(9.5、19、31.5 mm)代替30%天然骨料进行组合而成。考虑钢纤维掺量和最大粒径粗骨料耦合作用,对钢纤维再生混凝土的抗冲击性能进行分析。同时,基于Weibull分布理论模型,对钢纤维再生混凝土的冲击次数进行了拟合分析和不同失效概率下抗冲击次数的估计。结果表明,当钢纤维体积掺量相同时,再生混凝土的抗冲击性能随着最大粒径的增大,表现出先增后减的趋势,且在最大粒径为19 mm时表现最优;当最大粒径相同时,钢纤维再生混凝土抗冲击性能随着钢纤维体积掺量的增加而提升。通过数据统计分析,钢纤维再生混凝土的抗冲击次数很好地服从两参数Weibull分布,抗破坏冲击次数估计值随失效概率的升高而增加。In order to investigate the effects of different maximum particle size coarse aggregates and steel fiber contents on impact resistance of recycled concrete,a modified drop weight impact test device was used to test the impact test of 72 cylindrical specimens.Twelve kinds of concrete mixtures were prepared,which respectively were combined with different steel fiber volume admixtures(0,0.8%,1.0%,1.2%)and recycled coarse aggregate with different maximum particle sizes(9.5,19,31.5 mm)instead of 30%natural coarse aggregate.Regarding large experimental data obtained,considering the coupling effect of steel fiber contents and the maximum particle size of coarse aggregates,the impact resistance of steel fiber recycled concrete were analyzed.At the same time,the Weibull distribution function was introduced to analyze the impact test results and predict the impact resistance numbers under different failure probabilities.The results showed that the impact resistance of steel fiber recycled concrete showed a tendency to decrease after increasing with the increase of the maximum particle size when the volume content of steel fiber was certain,and the steel fiber recycled concrete with the maximum particle size of 19mm achieved the best.Concerning the constant maximum particle size,with the increase of steel fiber content,the impact resistance of steel fiber recycled concrete showed an increasing trend.Through statistical analysis of data,the probabilistic distributions of impact resistance numbers of steel fiber recycled concrete follow the two-parameter Weibull distribution,and the estimated value of impact resistance numbers for failure increased with the increase of failure probability.

关 键 词：再生混凝土 最大粒径 冲击试验 冲击次数 WEIBULL分布 

分 类 号：TU528.041[建筑科学—建筑技术科学]