[This article belongs to Volume - 53, Issue - 04]
Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-16-10-2021-64

Title : Freeze-thaw Resistance Evaluation of Lightweight Aggregate Concrete with Stress Damage Based on GM(1,1)
GAO Chu, KONG Xiangzhen, SHEN Xiangdong,

Abstract :

The key to the evaluation of freeze-thaw performance of lightweight aggregate concrete after disaster lies in the accurate quantitative description and prediction of its freeze-thaw performance under the specific disaster degree. The initial stress damage of lightweight aggregate concrete was applied by repeated loading to simulate the disaster, and the relative dynamic elastic modulus was taken as the evaluation index to study the freezing-thawing performance of lightweight aggregate concrete with the initial damage degree of 0, 0.05, 0.12, 0.19 and 0.27, respectively. The grey system theory was introduced into concrete frost resistance durability study, the relative dynamic elastic modulus measured data was used to build prediction model of freeze-thaw resistance of stress-damaged lightweight aggregate concrete based on GM(1,1), and corresponding comparation with the revised Loland concrete damage model and accuracy analysis was performed; The GM(1,1) prediction model was used to evaluate the effect of initial stress damage on the frost resistance durability of lightweight aggregate concrete and predict its frost resistance life. The results showed that the initial stress damage could accelerate the freeze-thaw performance degradation of lightweight aggregate concrete, and the higher the initial stress damage degree was, the faster the deterioration rate would be. The average relative error of GM(1,1) model was less than 4.5% under each initial damage degree, and the prediction accuracy of GM(1,1) model was generally higher than that of the revised Loland model. Lightweight aggregate concrete had a good freezing-thawing resistance, and its freezing-thawing resistance life could reach 45 years in central and western Inner Mongolia. When the initial damage degree was 0.05, 0.12, 0.19 and 0.27, the freezing-thawing resistance life was shortened to 30 years, 25 years, 17.5 years and 10 years, respectively. The prediction model of freeze-thaw performance of stress-damaged lightweight aggregate concrete based on GM(1,1) could accurately evaluate the whole process of freeze-thaw performance of the damaged lightweight aggregate concrete after disaster, which provided theoretical basis for guiding the engineering practice of lightweight aggregate concrete in cold and dry regions of north China.