Daily strength testing of the Portland cement mortars

Abstract

The study of daily tests (1-28 days) for compressive and flexural strength of cement mortars is presented in the article. The mortars were made from ordinary Portland cement, two different classes of cement were considered. Graphs with daily test strengths were obtained from the results of the experiment and the test results were fitted by exponential curves. To estimate the strength rates of mortars, numerical derivatives are calculated from experimental data and the exponential curves are fitted by the obtained values of numerical differentiation. As a result of experimental data processing, it was found that the flexural strength rate decreases to zero on the 12-14th day hardening of mortars, which can be explained by the end of the formation of macroporosity (voids) of the cement paste and the end of the chemical-physical processes of the formation of most contacts between the cement paste and the aggregate (sand grains).