| The main types of volume change in concrete that affect the performance of structures by causing stresses, crack, and deflection are creep and shrinkage. In this study, a concrete creep test was conducted on different concrete mixes to investigate age of loading, compressive strength, and the long-term effect on creep of concrete. Five different code models, namely the ACI 209R-92, B3, CEB 90, CEB MC90-99, and GL2000, were utilized in this study. The study results showed that creep increased over time; however, the rate of increase diminished after 250 days. Furthermore, increasing age of loading and compressive strength lowered concrete creep. We also introduced a new device for measuring autogenous shrinkage of cement paste to investigate mixes with different water-to-cement ratios containing fly ash or silica fume. We concluded that as the water-to-cement ratio decreased, the autogenous shrinkage increased. Also adding fly ash and silica fume decreased autogenous shrinkage. |
