钢纤维增强磷酸镁水泥混凝土力学性能研究  

Investigation on the mechanical properties of steel fiber reinforced magnesium phosphate cement concrete

作　　者：李茂 岳燕飞[2] 钱觉时[2] 贾兴文[2] 代小兵 林璐丹 LI Mao;YUE Yanfei;QIAN Jueshi;JIA Xingwen;DAI Xiaobing;LIN Ludan(Research and Development Center of Transport Industry of Technologies,Materials and Equipments of Highway Construction and Maintenance,Gansu Road&Bridge Construction Group,Lanzhou 730030,China;School of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]甘肃路桥建设集团有限公司公路建设与养护技术、材料及装备交通运输行业研发中心,甘肃兰州730030 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《武汉大学学报（工学版）》2022年第7期691-698,共8页Engineering Journal of Wuhan University

基　　金：甘肃路桥建设集团有限公司开放基金项目(编号:GLKF201805)。

摘　　要：通过掺入不同长度(12、6 mm)及掺量的短切钢纤维,研究了钢纤维对磷酸镁水泥(magnesium phosphate cement,MPC)混凝土的流动性、力学性能及韧性的作用。结果表明,钢纤维的掺入会降低新拌MPC混凝土的坍落度,一定程度上抑制其流动性;尽管加入钢纤维对MPC混凝土的抗压强度无明显改变,但其对混凝土的抗折强度却有显著提升作用,以掺量2%的12 mm长钢纤维效果最为显著,掺入钢纤维后3 h的抗折强度可提高89.8%,随龄期增长钢纤维增强作用有所降低,但仍能保持在30%以上;同时,6、12 mm的钢纤维分别使试件断裂位移提高2、7倍,明显改善了混凝土的韧性。此外,通过计算单位截面积的钢纤维数研究了骨料对纤维分散性的影响,结果表明粗骨料含量越多,对钢纤维的分割阻碍作用就越明显,使钢纤维更易团聚。The effects of steel fibers on the fluidity,mechanical properties and toughness of magnesium phosphate cement(MPC)concrete were studied by incorporating short-cut steel fibers of different lengths(12 mm and 6 mm)and amounts.The results show that the incorporation of steel fiber of different lengths reduces the slump of fresh MPC concrete,inhibits its fluidity to a certain extent,and the newly mixed MPC concrete has good fluidity.Although the use of steel fiber does not change the compressive strength of MPC concrete,the flexural strength of concrete is significantly increased.The effect of incorporation of 12 mm long steel fiber with dosage of 2%is the most significant,and the 3 h flexural strength can be increased by 89.8%.The effect of steel fiber on the flexural strength decreases with age,but can still be maintained at more than 30%.The uses of 6 mm and 12 mm steel fibers can increase the fracture displacement of the specimen by 2 and 7 times,respectively,and significantly improve the toughness of concrete.In addition,by calculating the number of steel fibers per unit cross⁃sectional area,the effects of the aggregate on the fiber dispersibility were studied.The results show that the higher the aggregate content is,the more obvious the blocking effect on the dispersion of steel fibers,and the easier the agglomeration of steel fibers.

关 键 词：磷酸镁混凝土 钢纤维 流动性 力学性能 纤维分散 

分 类 号：TU528[建筑科学—建筑技术科学]