Characteristics of Concrete in Two Structures Completed about Seventy Years Ago

Concrete undergoes deterioration over time, and in extreme cases, this can lead to degradation of the structure. The collection of samples of actual structures that have remained sound over long periods of time and the detailed evaluation of their properties are extremely important in terms of providing empirical data regarding deterioration over time. In the present study, concrete collected from two structures completed around 1940 underwent naked eye observation, estimation of mix proportions, evaluation of mechanical properties, EPMA mapping analysis, measurement of pore size distribution, etc. Both concretes were considered to have been worked carefully and exhibited extremely little deterioration.