（郑州大学土木工程学院， 郑州 450001）

［摘要］采用磷酸镁水泥、普通硅酸盐水泥、快硬硫铝酸盐水泥和微细钢纤维制备叠层修复材料，通过叠层修复板的受弯试验，探索了叠层厚度、微细钢纤维体积掺量和水泥类型等对叠层修复板受弯性能的影响。结果表明：弯曲荷载作用下，普通混凝土叠层修复板的破坏形式为跨中折断的脆性破坏，微细钢纤维传统水泥（普通硅酸盐和快硬硫铝酸盐水泥）砂浆叠层修复板的破坏形式为跨中多裂缝的韧性破坏，而微细钢纤维磷酸镁水泥砂浆叠层修复板的破坏形式为分叉多裂缝的韧性破坏；相同叠层厚度下，微细钢纤维磷酸镁水泥砂浆叠层修复板的承载力更高，其韧性和变形适应能力更强，叠层修复效果更好；随微细钢纤维体积掺量增加，微细钢纤维磷酸镁水泥砂浆叠层修复板开裂荷载和峰值荷载均缓慢增加；随叠层厚度增加，微细钢纤维磷酸镁水泥砂浆叠层修复板的开裂荷载、峰值荷载及峰值荷载对应的跨中挠度均逐渐显著增加。

［关键词］微细钢纤维； 磷酸镁水泥； 裂缝捕捉； 叠层； 受弯试验

中图分类号：TU375文献标识码：A文章编号：1002-848X(2019)08-0103-05

Experimental study on bending behavior of micro steel fiber magnesium phosphate cement mortar laminated restoration plate

Feng Hu, Wang Zhenyu, Gao Danying, Zhao Jun, Zhao Kunpeng

(School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China)

Abstract:Magnesium phosphate cement, ordinary Portland cement, fast-hardening sulphoaluminate cement and micro steel fibers were used to prepare laminated restoration materials. The effects of lamination thickness, volume fraction of micro steel fibers and type of cement on the flexural properties of laminated restoration plates were investigated by bending experiments. The results show that under bending load, the failure mode of common concrete laminated restoration plate is brittle fracture at mid-span. The failure mode of traditional micro steel fiber cement (ordinary Portland cement and fast-hardening sulphoaluminate cement) mortar laminated restoration plate is ductile failure at mid-span with multi-cracks, while the failure mode of micro steel fiber magnesium phosphate cement mortar laminated restoration plate is fracture toughness failure bifurcated with multi-crack. Under the same lamination thickness, the laminated restoration plate with micro steel fiber magnesium phosphate cement mortar has higher bearing capacity, stronger toughness and deformation adaptability, and better lamination restoration effect. With the increase of volume fraction of microsteel fibers, the cracking load and peak wad of the laminated restoration plate with micro steel fiber magnesium phosphate cement mortar increases slowly. With the increase of lamination thickness, the cracking load, peak load and mid-span deflection corresponding to peak load of micro steel fiber magnesium phosphate cement mortar laminated restoration plate increase gradually.

Keywords:micro steel fiber; magnesium phosphate cement; crack capture; lamination; bending experiment

*国家自然科学基金（51308504），河南省科技攻关项目（152102310068），河南省高等学校青年骨干教师培养计划。

作者简介：冯虎，博士，副教授，硕士生导师，Email: fenghu@zzu.edu.cn。