SPACE system for simulation of aggregated matter application to cement hydration

Abstract

This paper presents the basic features of the Software Package for the Assessment of Compositional Evolution (SPACE). SPACE consists of a two-stage simulation strategy, providing successively for the three-dimensional packing of a particulate system and the structural evolution, the latter representing a sintering, foaming, or hydrating particulate system. Hence, SPACE has versatile potentialities. The initial distribution results from a generation process in which a predefined number of particles are dynamically mixed using a Newtonian motion model. Bulk material and interfaces can be simulated. The results obtained have been demonstrated to be realistic. Next, this paper deals with the simulation of cement hydration as an illustrative application of the SPACE system. The model starts with a simulated spatial distribution of anhydrous cement particles in a water-filled volume and simulates the hydration process through a series of relatively simple growth rules, which are iterated many times. The kinetic hydration model used here is similar to one used by van Breugel. The chemical reaction between cement and water results in expansion of the particle and in the formation of multiple contacts with other hydrating particles. The effects of this interparticle contact as well as the effect of water consumption on the hydration and expansion rate have been explicitly accounted for, with the aid of a surface sampling method that can efficiently evaluate the degree of contact between particles. Results from various numerical experiments will show the microstructural development in bulk and in the interfacial zone.