Mechanical properties of preplaced lightweight aggregates concrete

Abstract

Preplaced casting scheme is applicable for manufacturing the minimum unit weight lightweight aggregate concrete with a higher content of lightweight aggregates. High-volume of aggregate can be achieved by fully packing aggregates in the empty formwork and filling the interstitial voids with grout mixtures. This unique manufacturing process of preplaced lightweight aggregate concrete forms extensively interconnected aggregate network with the grout-coated aggregate grains, influencing the mechanical characteristics of concrete. Thus, these complex homogeneities are considered in a micromechanical four-phase model, from which we predict the elastic properties of preplaced lightweight aggregate concrete. The inverse homogenization is used for the identification of equivalent homogeneous parameters of concrete composites referring the microstructural images of intermediate zone. The compressive strength and drying shrinkage of preplaced lightweight aggregate concrete are also investigated by proposing the corresponding micromechanics-based models using the elastic moduli of grout and equivalent aggregate network. Finally, the predicted strength and drying shrinkage well agree with the measurements on preplaced lightweight aggregates concrete.