基于细观损伤模型的混凝土湿度及干缩特性研究

将混凝土视为骨料与砂浆两相非均质复合材料,同时考虑材料损伤的影响。混凝土视为非均质体能较好的体现骨料和砂浆材料特性差异对湿度扩散及干缩应力的影响,内部出现的损伤也与混凝土视为均质体时明显不同。采用考虑材料特性差异及损伤作用的细观模型和计算方法,能更真实的反映混凝土的湿度、干缩变形和干缩应力分布规律。细观研究结果有助于更好地理解混凝土干缩裂缝的产生机理、开裂模式及发展规律。

STUDY ON CONCRETE MOISTURE AND DRYING SHRINKAGE BASED ON MESOSCOPICAL DAMAGE MODEL

This paper models the concrete to be an un-homogeneous composite material made of matrices and aggregates,and takes into account the influence of material damage,as well as the influence on the moisture and stress due to the differences in material characteristics of the aggregate and matrices.The damage distribution of the concrete was significantly different when it was modeled to be un-homogeneous.The actual distributions of moisture,dry shrinkage deformation and dry shrinkage stress were obtained by using the mesoscopical model and the calculation method considering the influence of damage and the differences in material characteristics.The mesoscopical result facilitates our understanding of the cracking mechanism,cracking model and the crack’s growth induced by the drying shrinkage.