一种新型无机微纤维在高强水泥基复合材料中的应用  

Mechanical propert ies of CaCO_3 whisker-reinforced high-st rength cement-based materials

作　　者：曹明莉[1] 张聪[1] 李昂[1] 姜道旭 

机构地区：[1]大连理工大学建设工程学部,辽宁大连116024

出　　处：《混凝土》2014年第7期85-88,共4页Concrete

基　　金：国家自然科学基金资助项目(51102035)

摘　　要：以高强水泥砂浆为基质材料,研究了材料的抗压强度、抗折强度、断裂功以及劈裂抗拉强度与碳酸钙晶须掺量之间的关系,并结合微观形貌观察讨论了碳酸钙晶须对硅酸盐水泥基材料的增强增韧机理。研究发现,碳酸钙晶须在抗压强度为98.0MPa的水泥砂浆中虽然出现了较多的晶须冲断现象,但是晶须的引入阻碍了基体内部微裂纹的扩展,因此在5%的质量掺量时材料的抗压强度和劈裂抗拉强度分别得到了8%和15%的提高;并且晶须通过晶须-水泥石基体脱黏、晶须剥离、晶须冲断等机制在掺量为10%时使试件的抗折强度和断裂功分别提高了12%和56%。研究认为,碳酸钙晶须并不会在高强水泥基材料中起到明显的增韧效果;碳酸钙晶须增韧水泥基材料时,其界面黏结强度需要适当的小,以便通过裂纹偏转机制发挥最佳的增韧效果。Compressive strength, flexural strength,work of fracture and split tensile strength of high-strength Portland cement mortar were determined as a function of CaCO3 whisker content.And the reinforcing and toughening mechanism was discussed based on the experimental results and micrographs of the fracture surfaces.It was found that the compressive strength and split tensile strength were increased by 8 % and 15 %, respectively, when the whisker mass content was 5 %.The flexural strength and work of fracture of the composite were increased by 12 % and 56 %, respectively, due to whisker-cement coalition debonding, whisker peeling and whisker impact breakage mechanisms when the whisker content was 10 %.However, the investigation indicated that the incorporation of CaCO3 whisker won＇t lead to a very significant effect on high-strength cement-based materials;Further more, the interracial bonding strength between whisker and cement matrix should be proper weak such that the optimal toughening effect could be achieved via the crack deflection mechanism.

关 键 词：碳酸钙晶须 高强水泥基材料 界面黏结强度 微观结构 增强 增韧 

分 类 号：TU528.041[建筑科学—建筑技术科学]