丁苯胶乳改性水泥混凝土的力学性能及耐久性实验分析

目前聚合物水泥混凝土已成为高性能混凝土研究的一个重要组成部分.中实验采用了一种聚合物乳液(丁苯胶乳)对高性能混凝土进行改性处理,研究不同丁苯胶乳掺加量对水泥混凝土基本力学性能、韧性、自收缩性能及抗氯离子渗透性能的影响.实验结果表明,丁苯胶乳改性水泥混凝土的抗压强度随着丁苯胶乳掺加量的增加有所降低;而丁苯胶乳的加入,对混凝土的劈裂抗拉强度、抗折强度及韧性有较大提高,且掺量为15%的增强效果最明显,劈裂抗拉强度和抗折强度的提升幅度分别达到17.4%和23.8%;掺量为10%的情况下韧度指数最高,增加幅度达到71.1%;丁苯胶乳改性混凝土浇注24h后的总收缩值,随着丁苯胶乳掺量的增加而逐渐减少,掺量为15%情况下的总收缩值降幅高达35%;同时,改性后水泥混凝土的抗氯离子扩散能力有所提高,抗渗性能也得到改善.

Experimental analysis on mechanical properties and durability of cement concrete modified by styrene-butadiene latex

Polymer cement concrete has become an important part of high-performance concrete research.In this paper,a polymer emulsion (styrene-butadiene latex,SBL) was adopted to modify high-performance concrete,and effects of different additive amounts on basic mechanical properties,toughness,autogenous shrinkage and chloride penetration resistance of cement concrete were studied.The results show that the compressive strength of cement concrete modified by SBL decreased with the increase of the content of SBL,while the addition of SBL could greatly improve the splitting tensile strength,flexural strength and toughness of concrete.When SBL addition was 15%,the enhancement was most obvious,and the increase of splitting tensile strength and flexural strength was 17.4% and 23.8%,respectively.The toughness index reached its peak at 10% SBL,with the increase of 71.1%.The total shrinkage value for 24 h after pouring of the modified cement concrete decreased with the increasing addition of SBL.The total shrinkage decreased by up to 35% at 15% SBL.At the same time,the anti-chloride diffusion ability and anti-permeability performance of modified cement concrete were improved obviously.