发布时间 : 星期五 文章中低强度等级砼高性能化的技术途径更新完毕开始阅读
苏州科技学院本科生毕业论文
中低强度等级砼高性能化的技术途径
摘 要
本论文主要研究混凝土设计配合比参数中胶凝材料的总用量、水胶比、砂率以及混凝土的含气量对中低强度等级混凝土的性能，尤其是对新拌混凝土性能的影响规律，通过实验确定最佳配合比。即C40混凝土胶凝材料总用量小于等于400kg/m3，水胶比需控制在0.44左右，合理砂率为40%。通过掺加不同比例II级粉煤灰与S95级磨细矿渣至C40与C50混凝土中，考察活性矿物掺料对混凝土性能的影响。单掺粉煤灰与磨细矿渣均能提高新拌混凝土的流动性，单掺粉煤灰与磨细矿渣的掺量为15%时，C40混凝土拌合物坍落度损失分别降低了8.3%、5.6%，7d抗压强度相对于基准分别降低了7%、5.9%；单掺粉煤灰与磨细矿渣的掺量为25%时，C40混凝土拌合物坍落度损失分别降低了5.6%、2.8%，7d抗压强度分别降低了4.5%、2.8%。单掺粉煤灰比单掺磨细矿渣对混凝土的流动性的改善效果更明显。单掺两种矿物掺料后混凝土的早期强度均相对于基准混凝土有所降低，且粉煤灰比磨细矿渣对混凝土早期强度降低效果更明显。单掺分粉煤灰与磨细矿渣混凝土早期抗压强度均低于基准混凝土，混凝土后期强度均大于基准混凝土，且后期强度发展较快。
关键词 中低强度混凝土; 高性能化; 新拌混凝土工作性; 活性矿物掺料
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苏州科技学院本科生毕业论文
The technical approach of high performance processing
for middle and lower strength grade of concrete
Abstract
This thesis mainly studies the concrete mixture ratio design parameters in the total dosage of gelled material, water/cement ratio, sand ratio, and concrete's air content on the performance of the low strength grade of concrete, especially the regularity of influence on the properties of fresh concrete,and determine the best mix design through experiments. The total amount of gelled material of the C40 concrete should less than or equal to 400 kg/m3, water/cement ratio should be controlled about 0.44 , the reasonable sand rate was 40%. By adding different proportion of class II grade fly ash and S95 ground granulated slag to C40 and C50 concrete, studying the effect of active mineral admixture on concrete performance.Adding fly ash or ground granulated slag can improve the fluidity of fresh concrete, when the percentage of fly ash and ground granulated slag content was 15%, the slump loss of C40 concrete mixture was reduced by 8.3% and 5.6%,;respectively, 7 d compressive strength relative to a benchmark was reduced by 7% and 7% respectively. when the percentage of fly ash and ground granulated slag content was 25%, C40 concrete mixture slump loss was reduced by 5.6% and 2.8%,;respectively, 7 d compressive strength was reduced by 4.5% and 2.8%. The long-term compressive strength of fly ash and ground granulated slag concrete are higher than the benchmark concrete , while the development of the long-term strength is rapid. The effect to the improvement of the liquidity of fly ash on concrete is more obvious than fine grinding slag. After adding two kinds of mineral admixtures, the initial strength of concrete is lower than that of the blank concrete, and the slowing down effect on strength of fly ash is obvious than ground granulated slag.
Key words Middle and lower strength concrete; High-performance; Fresh concrete workability; Active mineral admixture
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苏州科技学院本科生毕业论文
目 录
第一章 绪论 .................................................................................................................... 1
1.1 研究背景 ............................................................................................................. 1 1.2 国内外研究现状与存在问题 ........................................................................... 2 1.3 中低强度混凝土高性能化的途径 ..................................................................... 2
1.3.1 粉煤灰 ...................................................................................................... 3 1.3.2 磨细矿渣 .................................................................................................. 3 1.3.3 高效减水剂和优质引气剂 ...................................................................... 4 1.4 研究目的与内容 ................................................................................................. 4 第二章 混凝土高性能化试验设计 .................................................................................. 6
2.1 试验原材料 ......................................................................................................... 6 2.2 试验仪器 ............................................................................................................. 7 2.3 试验方法 ............................................................................................................. 7
2.3.1 原材料性能试验方法 .............................................................................. 7 2.3.2 新拌混凝土坍落度及坍落度经时损失测定 .......................................... 7 2.3.3 硬化混凝土力学性能的测定 .................................................................. 8 2.3.4 新拌混凝土泌水率的测定 ...................................................................... 8 2.4 试验方案设计 ..................................................................................................... 8 第三章 混凝土配合比参数对混凝土性能的影响 .......................................................... 9
3.1 胶凝材料用量对混凝土性能影响 ..................................................................... 9
3.1.1 胶凝材料用量对新拌混凝土性能影响 .................................................. 9 3.1.2 水泥用量对硬化混凝土力学性能影响 ................................................ 11 3.2 水胶比对混凝土性能影响 ............................................................................... 12
3.2.1 水胶比对新拌混凝土性能影响 ............................................................ 13 3.1.2 水胶比对硬化混凝土力学性能影响 .................................................... 14 3.3 砂率对混凝土性能的影响 ............................................................................... 15
3.3.1 砂率对新拌混凝土性能影响 ................................................................ 16 3.3.2 砂率对硬化混凝土力学性能影响 ........................................................ 17 3.4 混凝土含气量对混凝土的影响 ....................................................................... 18
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苏州科技学院本科生毕业论文
3.4.1 含气量对新拌混凝土性能影响 ............................................................ 18 3.4.2 含气量对硬化混凝土力学性能影响 .................................................... 20 3.5 本章小结 ........................................................................................................... 21 第四章 矿物掺合料对混凝土的性能影响 .................................................................. 22
4.1 矿物掺合料对混凝土性能影响 ....................................................................... 22 4.2 矿物掺合料对新拌混凝土性能影响 ............................................................... 23 4.3 矿物掺掺合料对硬化混凝土力学性能影响 ................................................... 25 4.3 本章小结 ........................................................................................................... 27 第五章 结论 .................................................................................................................... 28 参考文献 .......................................................................................................................... 29 致 谢 .............................................................................................................................. 30 附录I 外文参考文献（译文） .................................................................................... 31 附录II 外文参考文献（原文） .................................................................................. 42
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