Estudo da heterogeneidade do concreto em função da hidratação

Abstract

Aiming to complement concrete heterogeneity studies and to work as an experimental basis for modeling this material at early ages, the present work combined calorimetric and mechanical tests in order to relate mechanical properties with hydration and further evaluate the dispersion of the results obtained. Specimens were produced and placed in a curing chamber connected to the adiabatic calorimeter so that the specimens had the same degree of hydration. Compression and 4 point bending tests were performed at different times, associating the results with hydration. Trend curves were determined from statistical software that related the degree of hydration to mechanical properties (compressive and tensile strength, modulus of elasticity and peak deformation). The same software calculated the dispersion of the values in relation to the plotted trend line (absolute and relative mean squared error) and in relation to themselves (mean, standard deviation, variance and coefficient of variation). The results showed that both mechanical characteristics and statistical parameters can be described by trend curves with high degree of accuracy. In addition, by combining results of the ultrasonic pulse assays with adiabatic calorimetry, the hydration degree of the percolation threshold varied between 8 and 11%. Finally, the dispersion (heterogeneity) of the results was smaller as the hydration degree increased, using both absolute and relative statistical parameters.