Laboratory Compaction Method for Dry-Consistency Concretes

Vibro-pressed concrete blocks have been used owing to their various advantages such as high productivity, precise dimensional control of products, and low waste production. As density and compressive strength of new components are obtained by compaction using hydraulic vibro-presses, the quality control is usually carried out at factory scale. The reproduction of the industrial compaction pressure in a laboratory scale test is a challenge of research. In this paper, a laboratory-confined uniaxial compressive method was implemented to evaluate the compaction behavior of dry-consistency concrete mixtures in similar hydraulic compaction pressures. An increase in the compaction energy was found to be correlated with the reduction of interparticle voids, as well as with the increase of density and compressive strength of concrete specimens, which proves the method applicability. Relaxation in concrete mixtures decreased with voids reduction; after compaction, the recovered elastic energy increased with the compaction energy, showing the benefits of the method. Gap-graded particle-size distribution mixtures reduced interparticle voids, achieving a target density of concrete mixtures with low water demand, an environmental benefit for concrete.