A recent alkali silica reaction (ASR)/delayed ettringite formation (DEF) expansion model was modified to account for the load-induced precracks within a structure. Factors such as the orientation of the exposure face, the reinforcement details, and the location of the strain measurements were also considered. The model was implemented for environmentally exposed large-scale reinforced concrete specimens. The model provided a satisfactory simulation of the expansion results, with most results within the extremities of the measured data. The model successfully simulated the expansion strains inside and outside the development length zone. The expansion induced by ASR/DEF deterioration mechanisms in large structural concrete members could be effectively modeled using the minimalist semiempirical formulation. © 2018 American Society of Civil Engineers.