基于冻融损伤下的高性能混凝土力学性能衰减规律研究
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摘要
为研究冻融损伤对高性能混凝土力学性能损失的影响,将混凝土置于水或盐溶液中快速冻融400次后,测其动弹性模量、抗折、抗压及劈裂抗拉强度。定性分析了冻融循环次数与上述四个评价指标间的关系,并分析了损伤度与相对剩余抗折强度及抗压强度之间的关系,建立了抗折强度的衰减方程。试验结果表明:随着冻融循环次数的增加,混凝土的动弹性模量、抗压、抗折和劈裂抗拉强度均逐步降低,抗压强度的衰减速率先增大后减小,动弹性模量、抗折、劈裂抗拉强度则是不断增大;相同冻融循环条件下,含气量越低、水胶比越大,冻融损失越大;冻融介质对混凝土的强度损失有一定影响,盐溶液对强度造成的损失更大;损伤度与相对剩余抗折强度间具有良好的相关性,但与抗压强度间不具有相关性。
In order to study the effect of freeze-thaw damage on the loss of mechanical properties of high-performance concrete, the concrete was placed in water and salt solution for 400 freeze-thaw cycles. Then, the dynamic modulus,flexural, compressive and splitting tensile strengths were measured. The relationship between freeze-thaw cycle times and the above four evaluation indicators was qualitatively analyzed, and the relationship between damage degree and relative residual flexural strength and compressive strength was also studied, and the attenuation equation of flexural strength was established. The test results show that with the increase of freeze-thaw cycles, the dynamic elastic modulus, compressive strength, flexural and splitting tensile strength of concrete are gradually reduced. The decay rate of compressive strength first increases and then decreases, but the dynamic elastic modulus, flexural resistance, splitting, and tensile strength increase continuously. Under the same freeze-thaw cycle conditions, the lower the gas content and the greater the W/B,the greater the loss of specimen quality, freeze-thaw medium has a certain influence on the strength loss of concrete.The strength loss of the specimen in the salt solution is greater. There is a good correlation between the degree of damage and the relative remaining flexural strength, however, there is correlation with the compressive strength.
In order to study the effect of freeze-thaw damage on the loss of mechanical properties of high-performance concrete, the concrete was placed in water and salt solution for 400 freeze-thaw cycles. Then, the dynamic modulus,flexural, compressive and splitting tensile strengths were measured. The relationship between freeze-thaw cycle times and the above four evaluation indicators was qualitatively analyzed, and the relationship between damage degree and relative residual flexural strength and compressive strength was also studied, and the attenuation equation of flexural strength was established. The test results show that with the increase of freeze-thaw cycles, the dynamic elastic modulus, compressive strength, flexural and splitting tensile strength of concrete are gradually reduced. The decay rate of compressive strength first increases and then decreases, but the dynamic elastic modulus, flexural resistance, splitting, and tensile strength increase continuously. Under the same freeze-thaw cycle conditions, the lower the gas content and the greater the W/B,the greater the loss of specimen quality, freeze-thaw medium has a certain influence on the strength loss of concrete.The strength loss of the specimen in the salt solution is greater. There is a good correlation between the degree of damage and the relative remaining flexural strength, however, there is correlation with the compressive strength.
引文
[1]田俊壮,夏慧芸,牛昌昌,等.冻融循环作用下盐分对混凝土耐久性影响的试验研究[J].混凝土与水泥制品,2016(3):1-6.
[2]洪锦祥,缪昌文,刘加平,等.冻融损伤混凝土力学性能衰减规律[J].建筑材料学报,2012,15(2):173-178.
[3]赵燕茹,范晓奇,王利强,等.不同冻融介质作用下混凝土力学性能衰减模型[J].复合材料学报,2017,34(2):463-470.
[4]秦晓川,孟少平,涂永明.高强混凝土材料细观冻融损伤与抗压强度的关系[J].材料导报,2017,31(2):117-120.
[5]曹芙波,唐磊杰,丁兵兵,等.冻融损伤后钢筋与再生混凝土黏结滑移性能试验研究[J].工程力学,2017,34(s1):244-251.
[6]曹大富,富立志,杨忠伟,等.冻融循环作用下混凝土受压本构特征研究[J].建筑材料学报,2013,16(1):17-23.
[7]魏强,谢剑,吴洪海.超低温冻融循环对混凝土材料性能的影响[C].第21届全国结构工程学术会议,2013:125-131.
[2]洪锦祥,缪昌文,刘加平,等.冻融损伤混凝土力学性能衰减规律[J].建筑材料学报,2012,15(2):173-178.
[3]赵燕茹,范晓奇,王利强,等.不同冻融介质作用下混凝土力学性能衰减模型[J].复合材料学报,2017,34(2):463-470.
[4]秦晓川,孟少平,涂永明.高强混凝土材料细观冻融损伤与抗压强度的关系[J].材料导报,2017,31(2):117-120.
[5]曹芙波,唐磊杰,丁兵兵,等.冻融损伤后钢筋与再生混凝土黏结滑移性能试验研究[J].工程力学,2017,34(s1):244-251.
[6]曹大富,富立志,杨忠伟,等.冻融循环作用下混凝土受压本构特征研究[J].建筑材料学报,2013,16(1):17-23.
[7]魏强,谢剑,吴洪海.超低温冻融循环对混凝土材料性能的影响[C].第21届全国结构工程学术会议,2013:125-131.