Long-Term Drying Shrinkage of GGBFS-Incorporated RCC under Various Temperature Exposures

Abstract

In this paper, the influence of different temperatures and ground-granulated blast-furnace slag (GGBFS) content on the compressive strength and shrinkage bahavior of roller-compacted concrete (RCC) was explored. For this purpose, four RCC mixes incorporating 0%, 20%, 40%, and 60% of GGBFS were prepared. The mixes were subjected to three temperatures, 25°C, 50°C, and 70°C. The results show that RCC gained strength more rapidly at higher curing temperatures. Shrinkage results showed that temperature had a direct impact on shrinkage strain development, with lower final shrinkage strain values at higher exposure temperatures. This was due to a loss of interlayer water at a faster rate in the early stages itself. Also, incorporation of GGBFS led to marginally higher shrinkage strain, which was compensated at higher exposure temperatures. Strength and shrinkage results were further confirmed at the microscopic level by scanning electron microscopy and thermogravimetry analyses. Based on the experimental results, a multivariable model incorporating the effect of temperature, time, and GGBFS percentage was developed for the prediction of shrinkage strain of RCC. The regression coefficient of the model was higher than 0.95 for all mixes, indicating that the proposed model can estimate shrinkage strain within 95% of the prediction band.