Influence of different curing conditions on density and compressive strength of hardened concrete with various types of chemical admixtures
Keywords:curing conditions, chemical admixture, hardened concrete, density, compressive strength
The research was made in order to determine the influence of the standard and non-standard curing conditions on the density and compressive strength of concrete specimens, when the mixture of concrete was modified by the use of different admixtures. From the same concrete mixture, part of the formed concrete specimens were cured according to the standard, another part - according to non-standard method. According to the requirements of the EN 12390-2:2009 standard, the specimens were cured for 28 days in water at the temperature of 20 ± 2ºC. Another part of the specimens, which were covered by polyethylene covering, were cured for 28 days in a room with the temperature of 20 ± 4ºC and relative humidity of 60 ± 2 %. After that, comparison of density and compressive strength values of specimens, cured in different conditions, was made. It was found, that the density of specimens cured by standard way was higher than the density of specimens which were cured in non-standard way, admixture type did not influence the results. The trends of compressive strength of concrete specimens, cured by different methods, depended on the percentage of admixture in the mass of cement.