三种掺合料对混凝土力学性能的试验分析  

Experimental analysis of mechanical properties of concrete with three admixtures

作　　者：杜明芳[1] 李艺博 DU Mingfang;LI Yibo(College of Civil Architecture,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学土木建筑学院,河南郑州450001

出　　处：《混凝土》2020年第9期97-100,共4页Concrete

基　　金：国家自然科学基金资助(51348376);住房和城乡建设部科学技术项目(2013-K4-25)。

摘　　要：为研究混凝土收缩率和力学性能的影响因素和原理,在传统混凝土材料的基础上添加纳米材料CaCO3以改善其活性,并以不同石棉和炉渣的掺量确定掺合料的最佳配合比。得出:随着时间的推移混凝土的收缩率也逐渐增大,并且混凝土的收缩率随着纳米材料CaCO3的比例增加而逐渐增加;纳米混凝土的收缩率随着石棉、炉渣比例增加而逐渐减少,且炉渣-纳米混凝土的收缩率比石棉-纳米混凝土要低得多。随着时间的推移混凝土的抗压强度也逐渐增大,并且混凝土的抗压强度随着纳米材料CaCO3的比例增加而逐渐增加;纳米混凝土的抗压强度随着石棉、炉渣的比例增多而逐渐减少,但炉渣-纳米混凝土的早期抗压强度比石棉-纳米混凝土要高。进一步通过微观测试得出其原理:在7 d后掺量1%纳米材料的混凝土微观结构中形成了大量的C-S-H凝胶体系;当时间到达一定程度时,石棉纤维和水泥的水化产物发生反应,使得混凝土内部结构更加密实;炉渣的存在会与混凝土中未发生水化反应的化学成分再次发生反应,使得混凝土内部孔结构发生改变:降低孔洞的连通性。因此,建议纳米材料CaCO3掺量0.4%、石棉掺量10%或炉渣掺量5%为最佳。该试验结果可为今后新型高性能混凝土设计提供依据。In order to study the influencing factors and principles of shrinkage and mechanical properties of concrete,nano-material CaCO3 was added on the basis of traditional concrete materials to improve its activity,and the optimum mix proportion of admixture was determined by the different amount of asbestos and slag.It is concluded that the shrinkage of concrete increases with the passage of time,and the shrinkage of concrete increases with the increase of the proportion of nano-material CaCO3.The shrinkage of nano-concrete decreases with the increase of the proportion of asbestos and slag,and the shrinkage of slag-nano-concrete is much lower than that of asbestos-nano-concrete.With the passage of time,the compressive strength of concrete increases gradually,and the compressive strength of concrete increases gradually with the increase of the proportion of nano-material CaCO3.The compressive strength of nano-concrete decreases gradually with the increase of the proportion of asbestos and slag,but the early compressive strength of slag-nano-concrete is higher than that of asbestos-nano-concrete.Further through microscopic tests,the principle is obtained a large amount of C-S-H gel system is formed in the microstructure of concrete after mixing with 1%nanometer material after 7 d.When the time reaches a certain level,the hydration products of asbestos fiber and cement react,making the internal structure of the concrete more dense.The existence of slag will react with the chemical composition of hydration reaction not occurred in concrete.Therefore,the internal pore structure of concrete should be changed to reduce the connectivity of the pore.Therefore,it is suggested that 0.4%CaCO3,10%asbestos or 5%slag are the best nanomaterials.The experimental results can provide a basis for the design of new high performance concrete in the future.

关 键 词：纳米材料 石棉 炉渣 混凝土 力学性能 试验 

分 类 号：TU528.01[建筑科学—建筑技术科学]