VAE乳胶粉改性砂浆耐久性能研究

针对实际工程应用中普通砂浆耐久性不足问题，研究了VAE乳胶粉对水泥砂浆耐久性改性效果，对不同聚合物含量（8%、9%、10%、11%和12%）的VAE乳胶粉改性砂浆通过收缩率、开裂性敏感度、抗渗性、耐氯盐腐蚀性和碳化实验，测试了收缩率、开裂总权值、渗水高度、透水压力、碳化深度以及氯离子渗透高度，结合扫描电镜实验，揭示了VAE乳胶粉对砂浆的微观改性机理。结果表明，VAE乳胶粉的加入显著提高了砂浆的抗渗透性。当聚合物含量为12%时，VAE乳胶粉砂浆的开裂总权值仅为普通水泥砂浆的55.1%，透水压力较普通水泥砂浆提高了78.6%，28 d碳化深度和氯离子渗透高度较普通水泥砂浆分别降低了36.8%、53.1%。VAE乳胶粉与砂浆中的骨料在浆体内部形成高黏结力的网状膜结构，填充改性砂浆的孔隙，使浆体内部更加密实，进而增强了改性砂浆的耐久性。

Research on Durability of VAE Latex Powder Modified Mortar

In view of the insufficient durability of ordinary mortar in practical engineering application,the durability modification effect of VAE emulsion powder on cement mortar was studied.For VAE latex powder modified mortar with different polymer content (8%, 9%, 10%, 11% and 12%),through shrinkage,cracking sensitivity,impermeability,chloride corrosion resistance and carbonation experiments,the shrinkage,total weight of cracking,water seepage height,water permeability pressure,carbonation depth and chloride ion penetration height were tested.Combined with SEM experiments,the micro modification mechanism of VAE emulsion powder on mortar is revealed.The results show that the addition of VAE emulsion powder significantly improves the impermeability of mortar.When the polymer content is 12%,the total cracking weight of VAE latex powder mortar is only 55.1% of that of ordinary cement mortar,the permeability pressure is 78.6% higher than that of ordinary cement mortar,and the 28 day carbonation depth and chloride ion penetration height are 36.8% and 53.1% lower than that of ordinary cement mortar respectively.VAE emulsion powder and the aggregate in the mortar form a network membrane structure with high adhesion inside the slurry,fill the pores of the modified mortar,make the interior of the slurry more dense,and then enhance the durability of the modified mortar.