聚丙烯纤维复合胶粉改性混凝土的抗冻性能.pdfVIP

学兔兔 2014年第 11期 混凝 土与水 泥制 品 2014 No．1l 11月 CHINA CONCRETE AND CEMENT November 聚丙烯纤维复合胶粉改性混凝土的抗冻性能 伏利鹏，杨建森，冯紫荻，杨福强，郑小军 (宁夏大学土木与水利学院，银川I 750021) 摘 要：针对冻融造成的混凝土路面剥蚀问题，采用聚丙烯纤维与聚合物胶粉和硅粉复合对混凝土进行改性， 应用正交试验方案研究了胶粉掺量、硅粉掺量、纤维掺量以及纤维长度四个参数对聚丙烯纤维复合胶粉改性混凝土 的抗冻性能的影响。结果表明，纤维掺量0．3％，纤维长度6ram，胶粉含量 10％，硅粉掺量2．5％的聚丙烯纤维复合胶 粉改性混凝土的抗冻性能最优；胶粉在水泥水化同时形成乳胶薄膜和引入气体能大幅度的提高混凝土的抗冻性；硅 粉能有效的改善混凝土内部的孔结构，提高抗冻性；聚丙烯纤维配合胶粉能减轻胶粉在混凝土出现微裂缝时所受的 拉应力，从而有效延长混凝土的抵抗冻融破坏的时间。 关键词：抗冻性；胶粉；聚丙烯纤维；正交试验；动弹模量衰减率 Abstract：For the matter of the concrete pavement denudation caused by freezing—thawing，a method is adopted to modify the concrete by compounding the polypropylene fiber．polymer latex powder and silica powder．The influences of the four parameters of the content of latex powder，the silica powder and fiber and the length of fiber on the freeing resis— tanee of polypropylene fiber composite powder modified concrete are studied by orthogonal experiments．The results show that the freezing resistance of polypropylene fiber composite latex powder modified concrete is optimal when the contents of fiber．1atex powder and silica powder are respectively 0．3％．10％ and 2．5％ and fiber length is 6 mm．Latex powder can significantly improve the freezing resistance of concrete by forming the latex thin film and introducing gas while the ee— ment hydrates．Silica fume can enhance the freezing resistance of concrete by improving the pore structure of internal concrete．Polypropylene fiber with latex powder can alleviate the tensile stress of latex powder when the micro—cracks OC— cur in concrete SO that it c