轻骨料纤维喷射混凝土力学性能及破坏特征数值研究

STUDY ON THE MECHANICAL PROPERTIES AND FAILURE CHARACTERISTICS OF LIGHTWEIGHT AGGREGATE FIBER SHOTCRETE

以喷射混凝土配比为基准,将3种不同掺量的陶粒和玄武岩纤维进行组合,配制出9组轻骨料喷射混凝土(Lightweight Aggregate Fiber Shotcrete,简称"LAFS")来探究陶粒与玄武岩纤维对LAFS抗压、抗拉及抗剪强度的影响规律,根据试验结果建立了LAFS强度预测模型,同时借助RFPA~(2D)软件模拟得到了LAFS受力过程中陶粒及玄武岩纤维的受力特征和破坏规律。结果表明:陶粒掺量与玄武岩纤维掺量对LAFS抗压、抗拉及抗剪强度的影响是交互的。试验分析得到陶粒掺量为116.248 kg/m~3、玄武岩纤维掺量为5.26 kg/m~3时LAFS性能最优。陶粒与LAFS的充分粘结是保证LAFS强度的关键,纤维在LAFS受力过程中整体性良好,在LAFS破坏之前可与混凝土基体共同受力。本研究可为工程上发展LAFS提供试验及理论依据。

On the basis of the shotcrete ratio,the 3 different amounts of ceramsite and basalt fiber are combined.Nine groups of Lightweight Aggregate Fiber Shotcrete(LAFS)were prepared to explore the influence of ceramsite and basalt fiber on the compression,tensile and shear strength of LAFS.Based on the test results,a LAFS strength prediction model was established.At the same time,with the help of RFPA2D software simulation,the force characteristics and failure laws of ceramsite and basalt fiber in the process of LAFS are obtained.The results show that the content of ceramsite and basalt fiber has an interactive effect on the compressive,tensile and shear strength of LAFS.Test analysis shows that the LAFS performance is the best when ceramsite is mixed with 116.248 kg/m3 and basalt fiber is mixed with 5.26 kg/m3.Adequate bonding of ceramsite and LAFS is the key to ensure the strength of LAFS.The fiber has good integrity during the LAFS stress process.Before LAFS breaks,it can bear the force together with the concrete matrix.This research can provide experimental and theoretical basis for the development of LAFS in engineering.