Conversion
Measurements of the degree of conversion of the concrete in existing buildings indicate that most concrete has reached a high level of conversion in a few years. The results of crushing tests on highly converted concrete specimens cut from beams also indicate that strength is very variable and that some concrete suffers substantial losses of strength with respect to the strength at one day on which the design was usually based. In the appraisal of buildings therefore it is advisable to assume that all concrete has reached or will reach, during its expected life, a high level of conversion, nevertheless, in the majority of constructions the loss of strength is not sufficient to endanger the structure.