A novel quantitative particle distance estimation method of low water/ binder cementitious composites (LW/B-CC): Modeling and verification

This paper intends to employ water film theory and 1H Low-field NMR (Lf-NMR) to quantitatively evaluate the particle packing state of low water/binder cementitious composite (LW/B-CC) at different scales. The specific approach involves establishing particle distance models to evaluate the macroscopic, mesoscopic, and microscopic particle packing states of LW/B-CC samples using water film theory and Lf-NMR. The results indicate that Macro_PD is positively related to the product of plastic viscosity and distance of aggregate segregation, Meso_PD shows negatively related to the elastic modulus of ITZ. And Micro_PD can indicate different hydration period. Finally, a multiple linear regression analysis is used to establish a quantitative relationship between PD of different scales and compressive strength. The established particle distance models at different scales are proved to have significant guiding implications for various properties of LW/B-CC. This study presents a novel evaluation method for the particle packing state and provides guidance for the mix design of LW/B-CC.