A Study of Air Entraining and Curing of Portland Cement Concrete

摘要

The report contains the standard method of field curing concrete test cylinders as compared with two other methods to determine the best practical method of field curing. Concrete test cylinders were made on twelve pavement projects, field cured in the three ways, and tested for strength at 7 and 28 days to measure the effects of the three methods of curing. As an additional step, cores were cut from the pavement concrete and tested in compression to provide another basis of comparison for the compressive strengths obtained from test cylinders. The use of polyethylene caps for curing concrete cylinders was found to be substantially more practical than either the standard method of curing or the use of moist storage boxes. In this part of the research project the effect of spreading, vibrating, screening and finishing on the entrained air content in portland cement concrete was measured. Nine pavement projects and nine bridge decks were included in this study. (Author)