ROLE OF THE SURFACE-MORPHOLOGY IN CEMENT GEL GROWTH DYNAMICS - A COMBINED NUCLEAR-MAGNETIC-RESONANCE AND ATOMIC-FORCE MICROSCOPY STUDY

H-1 nuclear magnetic resonance and atomic force microscopy have been c orrelated in-order to exploit the relation between the microscopic mor phological properties and the growth dynamics of cement gels during hy dration. Studies in a number of samples with different hydration kinet ics show that consideration of percolation, gel surface roughness, and related scaling properties is necessary for a thorough understanding of cement hydration kinetics. It is further shown that, at late hydrat ion times, the hydration rate is highly correlated with the cement gel surface roughness exponent chi. A model based on a random walk on a t hree-dimensional network of rough micropores is proposed in order to e xplain this effect. (C) 1997 American Institute of Physics.