树脂基改性玄武岩纤维增韧海水–海砂磷酸镁水泥砂浆性能  

Properties of Seawater Sea-Sand Magnesium Phosphate Cement Mortar Reinforced with Resin-Based Modified Basalt Fibers

作　　者：陈柯宇 张抒扬 闵万林 吴柯娴 夏晋 CHEN Keyu;ZHANG Shuyang;MIN Wanlin;WU Kexian;XIA Jin(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Zhejiang Institute of Communications Co.,Ltd,Hangzhou 310006,China)

机构地区：[1]浙江大学建筑工程学院,杭州310058 [2]浙江数智交院科技股份有限公司,杭州310006

出　　处：《硅酸盐学报》2024年第5期1532-1542,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金面上项目(52278278);浙江省杰出青年科学基金项目(LR21E080003);浙江省交通运输厅科技计划项目(2023007)。

摘　　要：为应对岛礁道路抢修需求,研究了树脂基改性玄武岩纤维材料对海水-海砂磷酸镁水泥砂浆的工作性、力学性能、抗疲劳性及微观结构的影响。制备早强磷酸镁(MPC)砂浆的凝结时间可控制在30 min内。纤维可改善MPC的弯曲变形能力,掺0.75%纤维样品的疲劳寿命较无纤维组提高约1个量级。砂浆的水化反应是强放热过程并伴随着结晶相含量提高,由鸟粪石等组成的凝胶与改性玄武岩纤维间具有强结合面,但内部孔隙率与孔洞变异性随纤维掺量增加而提高。开展现场快速修补试验,利用三维超声扫描、落锤弯沉、回弹及钻芯等手段综合评价面层的结构层特性。结果表明:新浇面层密实度高,表面回弹值与弯沉值分布均匀,证实了纤维增韧的海水-海砂拌合MPC体系具有可行性。Introduction Magnesium phosphate cement(MPC)is a novel construction material that forms a gel material consisting primarily of insoluble phosphate salts after reaction of alkaline components with magnesia and soluble acid phosphate salts.However,the ceramic properties of MPC are significantly deficient in terms of fatigue resistance and toughness,and can lead to failure under vehicle loads.Short-cut basalt fibers can inhibit the initiation and propagation of concrete microcracks,but tend to wrap around and agglomerate during mixing.In addition,China has abundant island reef resources,and large quantities of concrete materials are required in various infrastructure construction processes.Transporting sand and fresh water from inland increases project costs,and extreme climate conditions can cause transportation inconveniences.Therefore,the use of seawater and marine sand from island reefs for road repair without damaging the environment can achieve a goal of localizing raw materials and reducing transportation burden.In this paper,effect of resin-modified basalt fiber on the workability,mechanical properties,fatigue resistance,microstructure,and engineering properties of seawater-sea sand MPC mortar was investigated.Methods Dead-burned magnesia,ammonium dihydrogen phosphate,borax retarder,highly active silica fume,and ultrafine low-calcium fly ash were used to prepare two groups of mortars with seawater sea sand or freshwater river sand.The modified basalt fiber was prepared,in which the surface of the modified fiber after coating with resin has a twist and wrinkle,which strengthens the bite force between the fiber and the mortar matrix.Different meshing structures were formed between the mortar and the end head(lengths of 23-25 mm,tensile strength of 2900 MPa,Young modulus of 90 GPa).The basalt fiber with different volume fractions(i.e.,0%,0.25%,0.50%,0.75%and 1.00%)was added to investigate the effect of fiber content on the matrix properties.The workability(flowability,setting time),mechanical properties(compres

关 键 词：早强水泥砂浆 海水海砂 改性玄武岩纤维 力学性能 快速修复 

分 类 号：TU528[建筑科学—建筑技术科学]