共查询到20条相似文献,搜索用时 375 毫秒
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针对某国防工程需要配制具有高工作性、自防水混凝土的要求,通过采用掺加粉煤灰、膨胀剂、钢纤维、高效减水剂以及缓凝剂,优化配合比设计,检测其力学性能、流动性、限制膨胀率和限制干缩率、静水压力等性能。结果表明,掺入钢纤维和复合外掺剂有效地提高了混凝土的力学性能,增加了混凝土的密实度,配制出具有高抗裂、高抗渗性能的自防水混凝土,满足工程要求的自防水要求。 相似文献
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主要阐述了在C50钢纤维防水混凝土桥面铺装中掺入MRT-3膨胀剂替代部分水泥,减少了混凝土的干缩裂缝,增强了混凝土结构的抗阻裂能力,从而满足桥面铺装对韧性、抗裂性能的需要。 相似文献
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本文以艺术浇注石的开裂问题作为研究探讨的对象,对艺术浇注石中存在的失水开裂、干缩开裂和表面龟裂的三种裂纹的形成机理及其预防改善措施进行了分析探讨,结果表明合理的养护制度可以避免失水开裂现象的发生;掺入粉煤灰,由于其活性和微集料效应可以改善艺术浇注石的干缩开裂;掺入细砂、粉煤灰及在浇注石的表面喷涂防水剂可以有效改善表面龟裂现象的发生。 相似文献
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Cui Hao Wang Shuotai 《工业建筑》2008,(Z1)
针对工业厂房大面积地面混凝土采用普通商品混凝土施工时容易产生裂缝的问题,通过采用掺高效减水剂、粉煤灰、膨胀剂等方法,配制出具有高抗渗、高抗裂、具有一定补偿收缩作用的混凝土;对于有耐磨要求的特殊地面,在普通补偿收缩混凝土中掺入一定量的钢纤维使混凝土的力学性能、抗渗抗裂性能、耐磨性能大大提高。 相似文献
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JIANG Jinyang SUN Wei ZHANG Yunsheng CHEN Cuicui WANG Jing 《Frontiers of Structural and Civil Engineering》2008,2(2):179
The mix ratio of steel fiber reinforced concrete (SFRC) was optimized using the principles that workability must meet the pumping demand and anti-cracking performance should be optimal. The effect of SFRC on the initial cracking load, the ultimate load and the crack width of the reinforced concrete (RC) member were analyzed in this paper. It was found that the admixture had good preservation of moisture and adhesion and the fibers distributed homogeneously in one hour out of the machine. According to the pumping results, the SFRC could be pumped vertically up to 306 m. Based on the standard computation formula of cracks, the maximum crack width of an RC member with 0.8% steel fiber (by volume) is about 32% lower than that of standard RC member. Through an experimental research on full-scale model tests for the steel and concrete composite anchorage zone on a pylon, the SFRC not only remarkably increases the crack resistance and the ultimate load, but the initial load also improves 33% approximately. It is also indicated that plastic shrinkage cracking of SFRC in which volume fraction of steel fibers is 0.8% can be restrained obviously and the unrestrained drying shrinkage can be diminished by about 50% at early age. The results confirmed that the SFRC can lessen the shrinkage crack of concrete and enhance markedly the direct tensile strength. Therefore, the SFRC can solve the key question of crack resistance for the anchorage zone of a bridge tower. 相似文献
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Jinyang Jiang Wei Sun Yunsheng Zhang Cuicui Chen Jing Wang 《Frontiers of Architecture and Civil Engineering in China》2008,2(2):179-183
The mix ratio of steel fiber reinforced concrete (SFRC) was optimized using the principles that workability must meet the
pumping demand and anti-cracking performance should be optimal. The effect of SFRC on the initial cracking load, the ultimate
load and the crack width of the reinforced concrete (RC) member were analyzed in this paper. It was found that the admixture
had good preservation of moisture and adhesion and the fibers distributed homogeneously in one hour out of the machine. According
to the pumping results, the SFRC could be pumped vertically up to 306 m. Based on the standard computation formula of cracks,
the maximum crack width of an RC member with 0.8% steel fiber (by volume) is about 32% lower than that of standard RC member.
Through an experimental research on full-scale model tests for the steel and concrete composite anchorage zone on a pylon,
the SFRC not only remarkably increases the crack resistance and the ultimate load, but the initial load also improves 33%a
pproximately. It is also indicated that plastic shrinkage cracking of SFRC in which volume fraction of steel fibers is 0.8%
can be restrained obviously and the unrestrained drying shrinkage can be diminished by about 50% at early age. The results
confirmed that the SFRC can lessen the shrinkage crack of concrete and enhance markedly the direct tensile strength. Therefore,
the SFRC can solve the key question of crack resistance for the anchorage zone of a bridge tower.
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Translated from Journal of Southeast University (Natural Science Edition), 2007, 37(1): 123–127 [译自: 东南大学学报(自然科学版)] 相似文献
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高掺量粉煤灰自流平砂浆性能的研究 总被引:4,自引:0,他引:4
本试验的自流平砂浆中粉煤灰含量高达 30 % ,并将高效减水剂、引气减水剂、增稠剂、膨胀剂复合掺用 ,研究表明 ,配制的水泥基自流平砂浆具有扩展度大、扩展度经时损失小的特性。扩展度达 2 4 5mm ,砂浆抗压强度39MPa,抗折强度 6 7MPa,同时 ,具有早期强度高、收缩小的特征。高掺量优质粉煤灰的掺入 ,不仅增加了砂浆的流动性 ,而且大大降低了成本 ,达到了技术和经济的双重效果。 相似文献
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采用单因素分析试验的方法,研究了粉煤灰、聚丙烯纤维和复合外加剂不同掺量对抗裂砂浆性能的影响。试验结果表明,随着粉煤灰、聚丙烯纤维掺量增加,抗裂砂浆的抗裂性明显改善,但粉煤灰的掺量过高或过低将使抗裂砂浆的抗压强度降低;复合外加剂的掺量过高或过低均会导致砂浆的干缩率、开裂指数增大。综合分析,抗裂砂浆最佳配合比为粉煤灰掺量40%,聚丙烯纤维掺量0.5%,复合外加剂掺量0.8%,水灰比0.7,灰砂比1∶3.5。 相似文献