细观等效理论预测再生混凝土宏观力学参数北大核心CSCD

预测分析再生混凝土各组分对再生混凝土宏观力学参数的影响是开展再生混凝土基本力学性能的一种方式.为了分析再生混凝土各组分对再生混凝土宏观力学参数的影响,根据再生混凝土的细观结构组成,建立了细观等效模型,利用扭转变形、细观夹杂理论、弹性等效思想和M-T模型方法,推导了由原生骨料、老界面层、老水泥砂浆、新界面层和新水泥砂浆等组成的再生混凝土的宏观力学参数预测模型.预测结果表明,随着再生骨料的取代率增加,水泥砂浆的含量不断增加,再生混凝土孔隙率也随之增大,导致再生混凝土的Poisson比随之增大,弹性模量、剪切模量和体积模量不断降低.模型的预测结果较好地反映了再生混凝土宏观力学参数随再生骨料取代率的增加不断变化的这一趋势,也为再生混凝土宏观力学参数的预测提供了一条简单实用的新方法,有利于再生混凝土基本力学性能的研究分析.

Prediction of the Macroscopic Mechanics Properties of Recycled Aggregate Concrete Based on the Mesoscopic Equivalence Theory

Prediction of the influence of each component of recycled aggregate concrete on the macroscopic mechanics properties of recycled aggregate concrete is a way to develop the basic mechanics properties of recycled aggregate concrete. For this purpose, a meso-equivalent model was established according to the meso-structure composition of recycled aggregate concrete. Based on the torsional deformation theory, the meso-inclusion theory, the elastic equivalent thought and the M-T model, the prediction model for macroscopic mechanics properties of recycled aggregate concrete composed of natural aggregate, old interface, old cement mortar, new interface and new cement mortar, was deduced. The prediction results show that, with the increase of the recycled aggregate replacement rate, the content of cement mortar and the porosity of recycled aggregate concrete rise, resulting in the increase of Poisson’s ratio of recycled aggregate concrete, and the decreases of the elastic modulus, the shear modulus and the volume modulus. The model well predicts the changing trend of the macroscopic mechanics properties of recycled aggregate concrete with the increase of the recycled aggregate replacement rate, and provides a simple and practical new way to the research and analysis of the basic mechanics properties of recycled aggregate concrete.