The Evaluation Method of Curing Effect on Pore Structure Formation and Initial Stress in High Performance Concrete

高性能混凝土养护效果对孔结构形成和初始应力的评价方法

基本信息

批准号：
06555125
负责人：
MAEKAWA Koichi
金额：
$ 8.64万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The purpose of this study is to develop a method to evaluate the initial stresses and the micro pore structure formation in self-compacting high performance concrete. For this purpose, a theory of the consumption and transfer of moisture in the pore structure, development of micro pore structure of hydration products according to hydration progress and the production and transfer of thermal energy was constructed based upon thermodynamical concepts. This enables a rational evaluation of the influences of drying, heat and external loads introduced to high performance concrete at early ages in an overall evaluation system.At first, the hydration heat model of cement based on the arrhenius's law of chemical reaction was proposed under arbitary temperature history, in which the chemical composition of cement used and mix proportion of concrete were adopted as imput data. As next step, the micro pore structure development in concrete was formulated in terms of the hydration progress, where … More the linearity of bulk porosity in the hydrated cluster around the particles were assumed. Also, the moisture transport and distribution model in concrete was proposed by considering the thermodynamic equilibrium of moisture in the pore in a unified adsorption condensation process. Furthermore, the prediction model of volumetric change in concrete due to drying was proposed through the evaluation of maximum pore size saturated by pore water and surface tension given by moisture transport model. Besides, the constitutive law was also proposed to predict the permeability of concrete, considering the random geometrical characteristics of micro-pore structure. Finally, these generalized models of simulation were systematically integrated with rational consideration of relations among them as FEM program "DuCOM3" on the behavior of high performance concrete at early ages. The proposed models were verified through versatile experimental data with respect to time, such as temperature rise, strength development, weight loss, volume change, pore structure distribution and so on. Less

这项研究的目的是开发一种评估自我压缩高性能混凝土中初始应力和微孔结构形成的方法。为此，根据热力学概念构建了水分结构中水分消耗和转移的理论，水合产物的微孔结构的发展以及热能的产生和传递。这使得在整体评估系统中对高性能混凝土引入的干燥，热量和外部负荷的影响进行合理评估。首先，根据Arrhenius的化学反应定律的水泥热模型在任意温度历史上提出了水泥的水泥热模型，在该温度史上提出了水泥的化学成分，在该水泥中使用了水泥的化学成分和混凝土组合的混合组合。在下一步中，根据水合进展制定了混凝土中的微孔结构的发育，在这里……假定颗粒周围水合簇中的散装孔隙率的线性更多。同样，通过考虑在统一的吸附凝结过程中考虑孔中水分的热力学平衡，提出了混凝土中的水分传输和分布模型。此外，通过评估水分传输模型给出的孔隙水和表面张力饱和的最大孔径，提出了由于干燥而导致的混凝土变化的预测模型。此外，考虑到微孔结构的随机几何特征，还提出了本构定律来预测混凝土的渗透性。最后，这些广义的模拟模型是系统地集成的，对它们之间的关系的合理考虑是fem程序“ ducom3”，涉及早期高性能混凝土的行为。通过使用多功能实验数据来验证所提出的模型，例如温度升高，强度发育，体重减轻，体积变化，孔结构分布等。较少的