文档介绍：摘要摘要混凝土砌块能够取代粘士砖,避免可耕地的大量减少,是困家建设部制定十“纲要中明确大力发展的新型建材;但由于混凝土砌块收缩率差异大,目}讨的普通抹而砂浆难以防止墙体出现裂缝和渗水现象,极大地影n向了建筑物的质量和使用寿命。针对这一问题,本文采用掺加纤维和聚合物二f粉的方法, 提高普通水泥砂浆的防裂抗渗作用,有望拓展混凝土砌块墙体的应用深度和广度,为可持续发展作出贡献。本文研究了抹面砂浆的配比,确定了水胶比、胶砂比及粉煤灰掺量等参数: 系统研究了搅拌方法对聚丙烯纤维在砂浆中分散均匀性的影响,得到了适合于纤维砂浆的搅拌方法;重点研究分析了纤维种类、聚丙烯纤维参数、羟乙基甲基纤维素等对砂浆力学性能、抗塑性收缩开裂和干缩开裂性能、二r缩率、抗渗性能等的影响,以及聚丙烯纤维和羟乙基甲基纤维素改性水泥砂浆的机理。研究表明,胶砂比为1:3、、粉煤灰掺量为10%时,砂浆的性能较好;先将砂、水泥、粉煤灰放入搅拌锅并开始搅拌,再将称量好的纤维在los内均匀加入,使之一起干拌20s,然后再在lOs内加入拌合水,继续搅拌至3min结束,用这种方法制备的砂浆中纤维的分散性较好:纤维的掺加使得水泥砂浆的抗压强度降低、抗折强度、粘结抗拉强度和劈裂抗拉强度均增大,砂浆的抗塑性收缩开裂和抗千缩开裂性能均显著提高,干缩率减小, 抗渗性能提高,特别是三叶形聚丙烯纤维砂浆,其抗裂性能和抗渗性能尤为突出:纤维种类和纤维参数(掺量、长度、细度、比表面积等)对砂浆各项住能均有影响;羟乙基甲基纤维素掺加使得水泥砂浆的抗压强度和抗折降低, 而断裂韧性、粘结抗拉强度和劈裂抗拉强度均增大,抗塑性收缩开裂和抗干缩丌裂性能提高,干缩率减小,抗渗性能提高:三叶形聚丙烯纤维和羟乙基甲基纤维素复掺能够显著改善砂浆的各项性能,其效果比两种物质单掺时的加合更为显著,%、%L1寸,砂浆的抗塑性收缩开裂和抗干缩开裂性能均达到了100%。关键词:水泥砂浆,纤维,聚合物干粉,力学性能,抗裂性能 A№In叭 Abstract Concrete block iS akindof new wallmatcrialinstead ofclay can avoid thedecrease ofarablelandevery year,SO itisdefinitelystipulated toapply and develop in“the Tenth Five—Year Plait’’established by Ministry of Construction,However,ordinary plastering mortar couldn’tprevent the wall built by concrete block from cracking and seepage,for concrete block have greater difference inshrinkage ratio,Inorder toresolve thisproblem,fiber andpolymer powder are mixer intocement mortar toimprove itsanti—cracking and waterproof properties on the research inthispaper,the application of concrete block as wall material can be extended,SO can make contribution for our continuable development. In thispaper,blending ratio ofplastering mortar isstudied,and some parameter,such aswater/cement ratio,cement/sand ratioand amount offly—ash, are effectofstirring methods on distribulion offiberinmortar is systemically so gets thebeststirring method forfiber—reinforced effects of fiber kinds,parameters of polypropylene fiber and hydroxyethyl methylcellulose on cement mortar pr