Segmented Fractal Pore Structure in Cement-Based Materials Blended with Dolomite Powder

Abstract

The macroscopic property of cement-based materials depends on their pore structure. Due to the complex and disordered pore structure of cement-based materials, traditional parameters like porosity and mean distribution radius are not accurate enough for strength predictions. Fractal geometry was employed to characterize the complexity of pore structure more accurately than existing parameters, especially the scale-dependent fractal properties, which are more dependent on the pore ranges. In this study, the pore size range of cement-based materials containing dolomite powder was regularly segmented to characterize the scale-dependent fractal nature of the pore structure. The relationship between the segmented fractal dimension and the compressive strength was discussed. Results based on the mercury intrusion porosimetry (MIP) and mechanical property tests showed that the difference existed in the relationship between segmented fractal dimension and dolomite powder content under various pore ranges. The relationships between compressive strength and fractal dimension of gel pores and fractal dimension of large pores presented positive and negative linear function, respectively. The strength equations expressed in terms of the segmented fractal dimension were proposed. Regression analysis proved that the equations in this study had high prediction accuracy.