Experimental Investigation into the Evolution of Probabilistic Characteristics of Early-Age Concrete

Abstract

This paper presents original findings on the heterogeneity of the mechanical properties of concrete of an early age, dependent on the evolution of the hydration reaction. The properties investigated are the compressive strength, the Young’s modulus, and the flexural tensile strength. To achieve this, we employed a testing apparatus in which the samples underwent curing in a chamber that followed the same temperature profile as an adiabatic calorimeter. This method enabled us to monitor the hydration progress across multiple samples. We used a function derived from the literature, with specific adaptations, to model the evolution of normalized properties in relation to hydration. Heterogeneity was quantified through the use of the dispersion coefficient. The key finding of this study is that the dispersion coefficient for the analyzed mechanical properties diminishes with the advancement of hydration, until reaching a specific threshold. Beyond this point, the impact of microcracking on the various properties becomes increasingly pronounced, varying according to the particular property being examined. Moreover, this paper presents initial functions designed to offer formulas that assist in modeling concrete within probabilistic numerical simulations from the early stages of its development.