Revisiting the concept of characteristic compressive strength of concrete

Abstract

The characteristic compressive strength is one of the most important material property used in structural design and quality control of concrete. Here we show that the estimation of this characteristic strength following classical standard rules (e.g. EN 1992 or ACI-318) is sample size dependent, i.e. is not a characteristic of the material. From an extensive experimental dataset, an analysis of published strength data, and an interpretation of compressive failure as a critical phase transition from an intact to a failed state, we show that the compressive strength of concrete is characterized by a non-vanishing asymptotic mean strength, , but a vanishing associated variability towards very large system sizes. Consequently, the asymptotic strength can be regarded as the genuine characteristic compressive strength of concrete. Based on this, we propose a new procedure to evaluate this genuine characteristic strength as well as to check the conformity of concrete with strength requirements.

Size effects on the mechanical behavior and the compressive failure strength of concrete: an extensive dataset

“…This data article presents the dataset obtained during the experimental campaign that was used in: [1] to analyze the statistical size effects on the compressive failure strength of concrete in terms of mean strength, associated variability, and probability distribution; and to investigate the influence of microstructural disorder on the size effects of strength; and in [2] to discuss and evaluate the genuine characteristic compressive strength of concrete by taking into account the size effects on strength.…”

“…3 of ref. [2] , those of P-wave velocity and dynamic elastic modulus have been displayed in Fig. 11 of ref.…”

“… [1] , the diameter of pore and porosity for the three different concrete mixtures have been presented in Table A1 of ref. [2] . Table 3 represents the details of dimensions, mass, density, and the compressive failure strength for different cylindrical ( concrete samples of F-concrete.…”

“… This data article provides a series of 492 stress-strain curves and compressive strength values obtained under the uniaxial compression of concrete samples fabricated from three different normal-weight concrete mixtures with four different cylindrical sample sizes ranging from 40 × 80 mm to 160 × 320 mm. These data are related to two research articles: “Revisiting statistical size effects on compressive failure of heterogeneous materials, with a special focus on concrete” (Vu et al., 2018) [1] and “Revisiting the concept of characteristic compressive strength of concrete” (Vu et al., 2020) [2] . In those papers, the strength values were used to (i) analyze and interpret statistical size effects on compressive strength of concrete (in ref.…”

“… [1] ), and (ii) discuss and evaluate the genuine characteristic compressive strength of concrete when size effects on strength are taken into account (in ref. [2] ). This dataset could be reused for other statistical analyses on the mechanical behavior of concrete (e.g.…”