ABSTRACT
In this research, normal concrete with three water-cement ratios (0.45, 0.5 and 0.6), self compacting concrete, enhanced selt compacting concrete and silica mme concrete are considered lor shrinkage study. An experimentally derived relationship between shrinkage and moisture loss is obtained for the various concretes and the following invariant form is suggested: εsh = αhygrp * ΔM where εsh = free shrinkage strain; αhygro = coefficient of moisture contraction; and ΔM = moisture loss percentage. Here anew concept of αhygro , referred to as coefficient of moisture contraction, is introduced. It is similar to that of coefficient of thermal expansion αtherm . The introduction of αhygro makes stress computations due to moisture movement rather convenient, much in the same manner as thermal stress computations. Loss of moisture ΔM can be obtained from the associated boundary value problem governed by Fick's law (analogous to change of temperature ΔT from the associated heat transfer problem), followed by computations of free shrinkage strain using the suggested form and the associated stress buildup can then be found by using a standard finite element package.
