Shrinkage of Micro-Synthetic Fiber-Reinforced Mortar

Abstract

Repair materials have been developed in this research by adding micro-synthetic fibers in cement-based mortar. In addition, accelerator is incorporated in the mortar to obtain high early strength of the repair materials. Their shrinkage behavior is of interest. This study aims to determine the shrinkage of the micro-synthetic fiber-reinforced mortar and propose models to reflect their shrinkage behavior. The results show that rapid developments of shrinkage are observed at an early age where the 3-day shrinkage already attains about 40–50% of the 84-day shrinkage value. Moreover, after 14 days of age the shrinkage curves tend to approach the asymptotic value. The ACI 209.2R-08 and CEB-MC 90-99 models do not reflect the shape of the shrinkage curves of the micro-synthetic fiber-reinforced mortar. Therefore, this research proposes a modified ACI 209.2R-08 and CEB-MC 90-99 that can describe the shrinkage behavior of the micro-synthetic fiber-reinforced mortar. The accuracy of the modified models has been confirmed quantitatively using the method of best fit line, residual analysis, and coefficient of error.