自溶型水泥基裂缝自修复材料的性能研究  

Autolytic self-healing performance for cracks in cement-based materials

作　　者：王心茹 李云霄 史金正 宋磊 祁义卿 王沛渊 王志丞 贾子轩 任书霞 WANG Xinru;LI Yunxiao;SHI Jinzheng;SONG Lei;QI Yiqing;WANG Peiyuan;WANG Zhicheng;JIA Zixuan;REN Shuxia(School of Materials Science and Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]石家庄铁道大学材料科学与工程学院,河北石家庄050043

出　　处：《混凝土》2023年第10期101-105,共5页Concrete

基　　金：国家自然科学基金(51402200);河北省自然科学基金(A2018210123);河北省教育厅重点项目(ZD2020192);大学生创新创业项目(202110107005,2021101070100)。

摘　　要：混凝土结构容易开裂,裂缝的存在势必影响其整体性和耐久性。以活化海泡石复合膨胀剂和硅酸钠为修复组分、溶于碱性溶液的聚乙烯醇缩丁醛(PVB)为涂层材料,研制了一种适用于水泥基胶凝材料的自溶型裂缝自修复材料。以强度恢复率和裂缝修复率为评价指标,探讨了该自溶型自修复材料对水泥砂浆裂缝自修复行为的影响,并结合XRD和SEM探究了微观自修复机理。结果表明,自溶型裂缝自修复材料的掺入能够显著提升水泥砂浆的强度恢复率和裂缝修复率。当其掺量为10%时,水中养护28 d修复的最大裂缝宽度可达0.38 mm,相应的强度恢复率和裂缝修复率分别达到了97%和100%。裂缝自修复机理在于:PVB涂层薄膜在碱性溶液中逐渐溶解并释放修复组分,生成大量与水泥基材料相容性好且高强和膨胀性的结晶物质以及高黏结力的C-S-H等凝胶。It is quite vulnerable to cracking for concrete structure.The presence of cracks in concrete can adversely affect its integrity and durability.An autolytic crack self-healing agents for cement-based materials is presented using activated sepiolite composite expansion agent and sodium silicate as repair components and polyvinyl butyral(PVB)as resoluble coating material which can be autolyzed gradually under alkaline solution.The self-healing effectiveness is evaluated by testing compressive strength recovery and crack healing rate of cementitious materials.It is discussed that the influence of the autolytic materials on the crack self-healing performance for cement mortar,and the self-healing mechanism is explored combined with XRD and SEM.Experimental results show that the strength recovery and crack repairing rate can be significantly improved by the adding the autolytic crack self-repairing material compared with control cement mortar.When its content is 10%,the prepared mortar specimens show better self-healing capacity than the control one.The values of completely healed cracked widths is up to 0.38 mm,and the corresponding strength recovery and crack repairing rate reached 97%and 100%,respectively,after curing in water for 28 days.The self-healing mechanism is that the PVB coating films gradually dissolve in alkaline solution and release the repair components,which react with resulting in a large number of crystalline materials with good compatibility,high strength and swelling properties and high cohesive strength C-S-H gels.

关 键 词：水泥基材料 自溶性 强度恢复率 裂缝修复率 自修复机理 

分 类 号：TU528.041[建筑科学—建筑技术科学]