干湿循环-硫酸盐耦合作用下混凝土相对动弹模灰熵关联度分析
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摘要
为研究混凝土在干湿循环与硫酸盐耦合作用下的损伤劣化,本文以相对动弹模为测试指标,通过试验研究了混凝土的相对动弹模在各个不同影响因素(粉煤灰的掺量、水胶比、Na2SO4的浓度、先期养护时间、不同的干湿循环制度(烘浸时间比))下随腐蚀龄期的演变规律。采用灰熵关联度理论分析了在不同腐蚀龄期各影响因素对混凝土相对动弹模的关联程度。结果表明:在干湿循环与硫酸盐耦合作用下,随着腐蚀龄期的增长,混凝土发生不同程度的损伤劣化,混凝土的相对动弹模也表现出不同程度的下降。不同腐蚀龄期,相对动弹模各影响因素的灰熵关联度排序是一致的。各影响因素对相对动弹模的灰熵关联度由大到小的排序为:水胶比、Na2SO4的浓度、不同的干湿循环制度(烘浸时间比)、先期养护时间、粉煤灰的掺量。
In order to study the degradation of concrete under drying-wetting cycles and sulfate attack,relative dynamic elastic modulus was used as test index in this paper,where the evolution rules of the relative dynamic elastic modulus with the corrosion age for concrete under different effect factors(content of fly ash,water-binder ratio,concentration of Na_2SO_4,early curing time,different drying-wetting circulation systems(different baking-immersing time ratio) were studied through experiments. The correlation degree of different effect factors to the relative dynamic elastic modulus of concrete at different corrosion ages was analyzed by gray entropy correlation degree theory. The results show that concrete damage occurred to some extent with the growth of corrosion age,and the relative dynamic elastic modulus of concrete also shows a different degree of decline. The gray entropy correlation degree of the effect factors to relative dynamic elastic modulus is the same on the order. The gray entropy correlation degree of each effect factor to the relative dynamic elastic modulus in decreasing order is: water-binder ratio,concentration of Na_2SO_4,different drying-wetting circulation systems(different baking-immersing time ratio),early curing time,content of fly ash.
In order to study the degradation of concrete under drying-wetting cycles and sulfate attack,relative dynamic elastic modulus was used as test index in this paper,where the evolution rules of the relative dynamic elastic modulus with the corrosion age for concrete under different effect factors(content of fly ash,water-binder ratio,concentration of Na_2SO_4,early curing time,different drying-wetting circulation systems(different baking-immersing time ratio) were studied through experiments. The correlation degree of different effect factors to the relative dynamic elastic modulus of concrete at different corrosion ages was analyzed by gray entropy correlation degree theory. The results show that concrete damage occurred to some extent with the growth of corrosion age,and the relative dynamic elastic modulus of concrete also shows a different degree of decline. The gray entropy correlation degree of the effect factors to relative dynamic elastic modulus is the same on the order. The gray entropy correlation degree of each effect factor to the relative dynamic elastic modulus in decreasing order is: water-binder ratio,concentration of Na_2SO_4,different drying-wetting circulation systems(different baking-immersing time ratio),early curing time,content of fly ash.
引文
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[3]Sahmaran M,Erdem T K,Yaman I O.Sulfate resistance of plain and blended cements exposed to wetting-drying and heating-cooling environments[J].Construction and Building Materials,2007,21:1771-1778.
[4]Yuan J,Liu Y,Tan Z C,et al.Investigation the failure process of concrete under the coupled actions between sulfate attack and drying-wetting cycles by using X-ray CT[J].Construction and Building Materials,2016,108:129-138.
[5]王海龙,董宜森,孙晓燕,等.干湿交替环境下混凝土受硫酸盐侵蚀劣化机理[J].浙江大学学报(工学版),2012,46(7):1255-1261.
[6]Wang A Q,Zhang C Z,Sun W.Fly ash effectsⅠ:The morphological effect of fly ash[J].Cement and Concrete Research,2003(33):2023-2029.
[7]Wang A Q,Zhang C Z,Sun W.Fly ash effectsⅡ:The active effect of fly ash[J].Cement and Concrete Research,2004(34):2027-2060.
[8]Wang A Q,Zhang C Z,Sun W.Fly ash effectsⅢ:The microaggregate effect of fly ash[J].Cement and Concrete Research,2004(34):2061-2066.
[9]刘芳,尤占平,汪海年,等.不同环境中矿物掺合料混凝土抗硫酸盐侵蚀性能的研究进展[J].中国材料进展,2014,33(11):682-688.
[10]邓聚龙.灰色系统理论教程[M].武汉:华中理工大学出版社,1990.
[11]张岐山,郭喜江,邓聚龙.灰关联熵分析方法[J].系统工程理论与实践,1996(8):7-11.