Influence of mix-designed parameters on frost thaw resistance of high performance concrete
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摘要: 为考察不同配合比设计参数对高性能混凝土抗冻性敏感特性的影响规律和显著性关系, 利用正交试验方法, 选取水胶比、粉煤灰掺量和砂率作为考察因素, 计算300次冻融循环后混凝土试件的抗折强度损失率和质量损失率, 并进行极差和方差分析。研究结果表明: 水胶比对高性能混凝土抗冻性有显著的影响, 而粉煤灰掺量和砂率均无显著影响; 冻融循环试验后的质量损失率不能准确地描述混凝土的抗冻性, 而抗折强度对冻融循环试验比较敏感, 建议采用抗折强度损失率作为高性能混凝土抗冻性的评价指标。Abstract: Taking water to binder ratio, fly ash percentage and sand ratio as mix-designed parameters, the influences of the parameters on the frost thaw resistance of high performance concrete (HPC) were studied with orthogonal experiments, the loss rates of bending strength and quality were calculated after 300 cycles of rapid freeze-thaw test, and their maximum difference binder ratio and variance were evaluated.The result shows that water to binder ratio has great influence on the frost thaw resistance of HPC, while fly ash percentage and sand ratio have little influence on the frost thaw resistance; the loss rate of bending strength is more sensible to freeze-thaw test than the loss rate of quality, so it should be used as the evaluation index of HPC.
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表 1 水泥化学成分
Table 1. Chemical composition of cement
化学成分 SiO2 Al2O3 Fe2O3 CaO MgO f-CaO 碱含量 不溶物 含量/% 21.68 5.34 3.47 64.98 1.17 0.58 1.04 0.07 表 2 粉煤灰化学成分
Table 2. Chemical composition of fly ash
化学成分 SiO2 Al2O3 Fe2O3 CaO MgO SO3 K2O Na2O 含量/% 59.34 20.06 9.70 4.18 2.07 0.79 2.17 0.71 表 3 因素水平
Table 3. Factor levels
水平 因素 水胶比 粉煤灰掺量/% 砂率/% A B C 1 0.344 0 38 2 0.310 20 36 3 0.282 30 34 表 4 试验配合比及试验结果
Table 4. Mix proportions and test results
编号 1 m3混凝土材料用量/kg 工作性 抗压强度/MPa 水泥 粉煤灰 水 水胶比 砂 石子 高效减水剂 坍落度/mm 扩展度/mm 7 d 28 d 56 d 1 450 0 155 0.344 701 1 144 6.75 145 300 58.9 68.2 76.1 2 360 90 155 0.344 664 1 181 6.75 215 530 43.0 58.0 62.3 3 315 135 155 0.344 627 1 217 6.75 220 530 43.8 61.0 63.4 4 500 0 155 0.310 646 1 148 7.50 75 — 64.8 68.6 82.6 5 400 100 155 0.310 610 1 184 7.50 225 530 54.8 67.3 77.9 6 350 150 155 0.310 682 1 113 7.50 230 560 55.9 72.4 85.6 7 550 0 155 0.282 593 1 151 8.25 30 — 67.0 71.0 65.8 8 440 110 155 0.282 663 1 082 8.25 245 555 51.9 74.4 74.5 9 385 165 155 0.282 628 1 117 8.25 240 580 43.2 66.8 70.0 表 5 冻融试验结果
Table 5. Freeze-thaw test result
编号 抗折强度损失率/% 质量损失率/% 试件外观描述 1 27.56 1.65 一端有胀起现象, 伴有严重剥落, 内部石子裸露, 表面有裂纹 2 38.42 -0.13 表面完好, 仅有轻微掉皮 3 33.77 0.13 表面较平整, 有掉皮现象, 一端有轻微剥落 4 -15.63 0.19 表面较完好 5 -26.91 0.00 表面完好, 无不良现象 6 2.46 0.26 表面有轻微掉皮现象, 两端有剥落 7 100.00 — 试件从中部完全冻断, 整个试件松散 8 89.76 -0.10 中部有严重裂纹, 几乎贯穿试件, 且伴有隆起现象 9 57.52 0.03 表面较完整, 有掉皮, 一端轻微掉角 表 6 极差分析结果
Table 6. Maximum difference analysis result
龄期 极差分析 考核因素 水胶比 粉煤灰掺量 砂率 56 d k1 33.25 37.31 39.93 k2 -13.36 33.76 26.77 k3 82.43 31.25 35.62 R 95.79 6.06 13.16 表 7 方差分析结果
Table 7. Variance analysis result
龄期 方差来源 离差平方和 自由度 均方离差 F值 显著性 56 d 水胶比 13 765.922 2 6 882.961 11.911 F0.1 (2, 2) =9F0.05 (2, 2) =19F0.01 (2, 2) =99 粉煤灰掺量 55.633 2 27.817 0.048 砂率 269.968 2 134.984 0.234 误差 1 155.744 2 577.872 总和 15 247.267 8 -
[1] 吴中伟. 高性能混凝土[M]. 北京: 中国铁道出版社, 1999. [2] 陈拴发, 高蕾. 高性能混凝土配合比设计参数对温缩系数的影响[J]. 长安大学学报: 自然科学版, 2005, 25(4): 1-4. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200504001.htmChen Shuan-fa, Gao Lei. Influence of mix-designed parameters on temperature shrinkage features of high performance concrete[J]. Journal of Chang'an University: Natural Science Edition, 2005, 25(4): 1-4. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200504001.htm [3] 陈拴发, 高蕾. 高性能混凝土腐蚀疲劳评价指标研究[J]. 西安建筑科技大学学报: 自然科学版, 2005, 37(2): 265-269. doi: 10.3969/j.issn.1006-7930.2005.02.026Chen Shuan-fa, Gao Lei. Study on evaluation index for corrosive fatigue with high performance concrete[J]. Journal of Xi'an University of Architecture and Technology: Natural Science Edition, 2005, 37(2): 265-269. (in Chinese) doi: 10.3969/j.issn.1006-7930.2005.02.026 [4] 李崇智, 冯乃谦, 董爱群. 大掺量粉煤灰高性能混凝土的强度推测及正交试验线性分析[J]. 混凝土, 2001, 23(1): 25-28. doi: 10.3969/j.issn.1002-3550.2001.01.007Li Chong-zhi, Feng Nai-qian, Dong Ai-qun. Strength inference of high performance concrete with large volume fly ash and proportional analysis of orthogonal experiment[J]. Concrete, 2001, 23(1): 25-28. (in Chinese) doi: 10.3969/j.issn.1002-3550.2001.01.007 [5] 罗季英, 冷发光, 冯乃谦, 等. 粉煤灰掺量对高性能混凝土强度和耐久性的影响[J]. 中国建材科技, 2001, 10(3): 15-18. doi: 10.3969/j.issn.1003-8965.2001.03.006Luo Ji-ying, Leng Fa-guang, Feng Nai-qian, et al. The effect of quantity of fly ash on the strength and durability of high performance concrete[J]. China Building Materials Science and Technology, 2001, 10(3): 15-18. (in Chinese) doi: 10.3969/j.issn.1003-8965.2001.03.006 [6] 巴恒静, 邓洪卫, 高小建, 等. 高性能混凝土微裂缝与显微结构的研究[J]. 混凝土, 2000, 22(1): 14-17. https://www.cnki.com.cn/Article/CJFDTOTAL-HLTF200001002.htmBa Heng-jing, Deng Hong-wei, Gao Xiao-jian, et al. Study on microcrack and micro construction of high performance concrete[J]. Concrete, 2000, 22(1): 14-17. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-HLTF200001002.htm [7] 陈瑜, 周士琼, 龙广成, 等. 大掺量粉煤灰高性能混凝土的试验研究[J]. 长沙铁道学院学报, 1999, 21(4): 63-67. https://www.cnki.com.cn/Article/CJFDTOTAL-CSTD199904013.htmChen Yu, Zhou Shi-qiong, Long Guang-cheng, et al. Experimental study on PFA high performance concrete with high replacement levels[J]. Journal of Changsha Railway University, 1999, 21(4): 63-67. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-CSTD199904013.htm [8] 吴文卿, 陈裕平, 谢麟, 等. 高强、高性能混凝土的研究[J]. 建筑科学, 2002, 18(3): 42-47. https://www.cnki.com.cn/Article/CJFDTOTAL-JZKX200203013.htmWu Wen-qing, Chen Yu-ping, Xie Lin, et al. Study on the high strength and high performance concrete[J]. Building Science, 2002, 18(3): 42-47. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JZKX200203013.htm [9] Khan M I L, Ynsdal E C J. Strength, permeability and carbonation of high performance concrete[J]. Cement and Concrete Research, 2002, 32(1): 123-131. doi: 10.1016/S0008-8846(01)00641-X [10] 吴炎海, 林震宇. 钢管活性粉末混凝土轴压短柱受力性能试验研究[J]. 中国公路学报, 2005, 18(1): 57-62. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200501013.htmWu Yan-hai, Lin Zhen-yu. Experimental study of behavior on RPC filled steel tubular stub columns under axial compression[J]. China Journal of Highway and Transport, 2005, 18(1): 57-62. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL200501013.htm [11] 陈拴发, 王秉纲. 高性能混凝土应力腐蚀评价指标[J]. 交通运输工程学报, 2005, 5(1): 6-10. http://transport.chd.edu.cn/article/id/200501002Chen Shuan-fa, Wang Bing-gang. Stress-corrosion-evaluation indices of high-property-concrete[J]. Journal of Traffic and Transportation Engineering, 2005, 5(1): 6-10. (in Chinese) http://transport.chd.edu.cn/article/id/200501002