Equations have been developed to estimate the replacement level of saturated LWFA needed to provide all of the water necessary for the complete curing of a high-performance concrete. This calculation assumes that no water exchange occurs with the external environment (sealed curing). Computer simulations have demonstrated that the protected paste volume concept applies to characterizing the cement paste within any given distance of the LWFA particle surfaces. Simulation results suggest that, similar to the case of air voids protecting concrete from damage due to freezing and thawing, a well dispersed system of small saturated LWFA particles would be most beneficial to the curing of field concrete. By applying a modification that represents the microstructure as a system of LWFAs randomly dispersed in cement paste, the analytical equations of Lu and Torquato , have been shown to provide a good estimation of the volume fraction of cement paste within a given distance of a LWFA surface. Thus, these equations may serve as a technical basis for the experimental optimization of the addition of LWFA to a given concrete mixture.