Study of the Material Properties of Aged Concretes Containing Various Cements,Parapet Wall, Green Mountain Dam

摘要

In 1940, the Portland Cement Association (PCA) and the Bureau of Reclamation(Reclamation) Materials Testing Lab, Denver, Colorado, formed a partnership to study the long term behavior of 27 different types of cement in concrete under service conditions. The 27 cements represented the range of physical and chemical properties of commercial cements used across the United States in the 1940s. Six of these cements were used with and without entrained air in the cement. The concrete mix design was the same for all specimens, only the cement composition and the source of aggregate varied. Tests on cast cylinders were conducted in the Denver laboratory as the wall was constructed in 1943. The study was intended to span several decades, yet project records of testing cease approximately thirty-eight months after the wall was constructed. This project resumed the study of the durability of various concrete mix designs after fifty years of environmental exposure. After completion of a visual inspection and non-destructive testing of all panels, fourteen cements were selected for coring and laboratory testing. Samples were tested for static compressive strength, dynamic compressive strength, splitting tensile strength, cyclic (nonlinear) compressive strength, modulus of elasticity, sonic modulus, Poisson's ratio, and unit weight.