Creep Model of Concrete at Early Ages

点击翻译按钮获取中文摘要

Creep behavior of concrete has been studied by many researchers, but almost all of them are concerned with matured concrete. This study has been conducted for prevention of cracking due to heat of hydration of cement in massive concrete. Compressive and tensile creep experiments have been carried out for early aged concrete such as from 1 day to 5 days. This study was focused on the influence of age of loading, term of loading, and stress level so on. It was noted from compressive creep experiments that specific creep was constant with no influence by stress level below 50% of compressive strength, however, that specific creep significantly increased at over the value. And the influence of stress level and specific creep decreased corresponding to age of loading. On the other hand, it was noted from tensile creep experiments that specific creep was not constant with influence by stress level over 20% of tensile strength.Furthermore, the method of modeling for change of stress has been investigated based on experimental results and applicability of super-positioning method for such stress has been assessed. it could be pointed out that a presented creep model which was modified Voigt model is applicable for early aged concrete and super-positioning method also could be applied for changing stress such as thermal stress which compressive stress level was below 50% of strength.