Numerical and Experimental Investigation of Wall Effect in Concrete

This study presents a new numerical approach using tools developed to perform a molecular simulation to investigate the wall effect on aggregates and mortar distribution in concrete. Aggregates are represented by spheres interacting via a generalized truncated Lennard-Jones potential. This approach allows obtaining the particle profiles according to the reference frame of interest (e.g., the confined directions). Then the particle-based distributions are transformed into continuum profiles of volume fractions using a convolution. Based on volume fraction profiles, transport or mechanical properties are estimated by the Mori-Tanaka scheme from classical homogenization. Results are compared to experimental work. The numerical method could be generalized and used for other applications in different fields. In civil engineering, perspectives include using the aggregate distribution to conduct a finer analysis, and the results would be extremely relevant for the prediction of the water content profile and the evolution of pathologies such as carbonation, corrosion, ISR, etc..