There are at least three basic questions that one can ask when considering mixture proportioning for internal water curing: 1) How much extra internal curing water needs to be supplied for a given concrete?, 2) How far can the water effectively travel from its reservoir (source)?, and 3) How is the internal curing water (or its reservoirs) distributed within the concrete microstructure? Each of these questions can be addressed using one or more computational modeling approaches. Many of the models discussed in this section are executable at an internal curing web site at http://ciks.cbt.nist.gov/lwagg.html.