复杂环境下混凝土动弹性模量的灰色预测

Grey prediction of dynamic modulus of elasticity of concrete under complex environment

干湿循环条件下混凝土性能所涉及到的问题较多,具有不确定性。在混凝土受干湿循环硫酸盐腐蚀的试验基础上,研究了不同环境条件下混凝土动弹性模量的变化规律,并运用灰色系统理论,对混凝土动弹性模量值进行了预测。结果表明,干湿循环条件下,试件的动弹性模量在初期有微小上升后明显下降;浸泡环境下,试件的动弹性模量先上升后缓慢下降,说明干湿循环较浸泡环境下混凝土腐蚀更快速。GM(1,1)灰色模型对混凝土动弹性模量预测精度较高,为混凝土受腐蚀破坏的预报提供了参考。

The concrete performance issues are complex, multifaceted and uncertain under wet and dry cycles. Dynamic elastic modulus is an important index in evaluating the concrete resistance of sulfate attack. On the basis of concrete tests in wet-dry cycles and sulfate corrosion, this paper studied the change rules of concrete dynamic elastic modulus in different conditions, and applied the grey system theory to predict the concrete dynamic elastic modulus values. The results showed that the dynamic elastic modulus of sample rises slightly in early stage and then descends significantly under dry-wet cycles, while increases first and then decreases slowly under immersion environment, which illustrates that the corrosion of concrete under dry-wet cycles is quicker than in immersion environment. The GM （1, 1 ） grey model has a high forecasting accuracy in concrete dynamic elastic modulus prediction, which can provide a reference for concrete corrosion damage forecasting.