Constitutive Law of Concrete in early ages Including Semi-fluid State and Analysis on Initial Crack Problem after Casting

点击翻译按钮获取中文摘要

In this year, constitutive law of concrete in transient state has been developed and application software to numerical problem has been tried to be created. Especially, following two targets are focused.One is to express fluidity of transient concrete mathematically. For the purpose of practical use, stress-strain relationship of fluid media is thought to be express in three dimensional tangential form including adequate homogeneous creep law. This is because even fluid media such as transient concrete has small but nonzero shear resistance. Moreover, numerical expression of plastic behavior except time dependent part is given by not classical plastic theorem but evaluating Lattice Equivalent Continuum Method (LECM) in order to have better numerical convergence of force equilibrium and to reduce computation time.The other is to present rigorous constitutive model in terms of both plastic theorem and various experiments.The aforementioned targets are almost completed. Finally, numerical analysis of transient concrete structure subjected to bleeding shrinkage is carried to reveal characteristics of software and it is found that the software can not only express strain localization induced by bleeding shrinkage more evidently but also have better numerical convergence of solution compared with the software based on conventional plastic theorem.However, as numerical discussion for initial stress problem is insufficient, much more numerical analysis of initial stress problem under various conditions should be carried and discussed.