Thermo-dynamics of concrete on generation and coupled transport of mass, energy and momentum.

1.建立了质量、比能和动量产生及耦合输运的广义热力学方程，形成并提出了统一以下内容的广义热力学方程。(a)考虑混凝土微孔中存在的矿物化合物和自由水的水泥水化模型。(b)集料、水泥基质和集料周围界面区微观孔隙结构中的水输运和质量交换模型。(c)微孔结构内部的比表面能模型。此外，给出了给定混凝土结构边界条件下控制方程的计算格式。在三维空间中对系统的有效性进行了数值验证。广义热力学方程的实验验证以下实际现象通过实验观察，并利用数值模拟技术对所提出的热力学方程进行了实验验证。(a)含有轻质人工集料的混凝土的干燥过程和相应的体积变化，其中包括微空隙。(b)绝对干燥阶段混凝土对水和有机液体的吸收过程。(c)氮气通过湿混凝土的渗透性。(d)一侧暴露于真空环境下混凝土试件的输水和温度梯度。(e)实际开放环境下混凝土1天养护后的温度分布及含水量梯度。

1.Establishment of generalized thermo-dynamic equations on generation and coupled transport of mass, specific energy and momentumThe generalized thermo-dynamic equations which unified the followings are formed and proposed.(a) Hydration model of cement in consideration of mineral compounds and free water existing in micro-pores of concrete.(b) Water transport and mass exchange model in micro-pore structures of aggregates, cement matrix and interfacial zone around aggregates.(c) Specific surface energy model inside micro-pore structures.Furthermore, computational scheme of the proposed governing equations was developed under given boundary condition of concrete structures. The validity of the system concerned was numerically verified in three-dimensional space.2.Experimental verification of generalized thermo-dynamic equationsThe following actual phenomena were experimentally observed and these were used for experimental verification of the proposed thermo-dynamic equations through a numerical simulation technique.(a) Drying process and the associated volume change of concrete which contains lightweight artificial aggregates including micro-voids inside it.(b) Absorption process of water and organic liquid through concrete of absolute drying stage.(c) Permeability of nitrogen gas through wet concrete.(d) Water transport and temperature gradient of concrete specimen which is exposed to vacuum environment in one side.(e) Temperature distribution and water content gradient of concrete under actual open environment after one-day curing.