Effect of Content and Fineness of GGBS on Pore Structure of Cement Paste

Abstract

The effect of the content and specific surface area of the ground granulated blast furnace slag (GGBS) on the pore structure of the cement paste was determined through the low-field nuclear magnetic resonance (NMR). The Pearson correlation analysis method was used to calculate the correlation coefficient between the porosity and age of cement paste, the specific surface area of GGBS and the content of GGBS. The test results exhibited that the porosity of the cement paste with different ageing durations gradually decreased on increasing the content and specific surface area of GGBS. The content and specific surface area of GGBS had a negligible effect on the 1–10 nm size gel pores in the cement paste, whereas, had a significant effect on the 10–100 nm size capillary pores. In addition, these parameters did not affect the final most probable pore size of the cement paste. The correlation between age and porosity was the largest, and the correlation between GGBS content and porosity was greater than that between GGBS specific surface area and porosity. Moreover, a modified pore structure model was successfully developed to effectively predict the pore structure of the GGBS based cement paste.

Keywords

ground granulated blast furnace slag / pore structure / fineness / cement paste / low-field nuclear magnetic resonance