新拌砂浆动态失水模型的建立

以毛细管力学理论及流体力学理论为基础建立砂浆动态失水数学模型,并用砂浆动态失水试验进行验证.研究了该模型与砂浆保水性的关联性,以模型为基础,探讨砂浆保水性的影响因素.结果表明:砂浆失水的前期阶段及后期阶段可分别用毛细管渐进式收缩模型及毛细管整体收缩模型模拟;毛细管渐进式收缩模型中砂浆失水量平方和失水时间的比值与砂浆的保水率呈线性反比关系,而毛细管整体收缩模型不能表征砂浆保水性;根据毛细管渐进式收缩模型,从理论上获得水的性质、胶凝材料的物料特性及灰砂比等对砂浆保水性的影响规律.

Establishment of Mathematical Model for Fresh Mortar Dynamic Dewatering Process

Mathematical model of mortar dynamic dewatering process was established based on theory of capillary mechanics and fluid mechanics, and verified through dynamic dewatering experiments. The relationship between model and water retention was further studied. Influence factors on water retention were discussed based on the model. The results indicated that the early stage and the later stage of mortar dewatering were simulated by Capillary Gradual Contraction Model (CGC) and Capillary Integral Contraction Model (CIC) respectively. An inverse linear relationship in CGC was found between the rate of square of dewatering quantity and dewatering time and water retention rate, and in CIC did not exist. In addition, the influencing rule on water retention of fresh mortar of water, binder and cement-sand ratio was obtained in theory according to CGC.