Aggregate type influence on strength and deformability of structural zero-slump concrete blocks: numerical, experimental, and statistical study

ABSTRACT

The structural masonry behavior results from the performance of each component: units, mortar joints, grouts, and reinforcement. Commercially, masonry blocks are made with called dry or zero-slump concrete. Its dosage and physical properties differ considerably from conventional concretes and depend on vibropress machines compaction efficiency. Testing full-size masonry elements is expensive and demand a specific infrastructure. Thus, computer modeling based on numerical formulations such as the Finite Element Method (FEM) can become viable and high potential alternatives. This work aims to analyze numerically and experimentally the influence of aggregate type on physical and, mainly, mechanical properties (ultimate strength and secant deformation module in compression) of hollow concrete blocks for structural masonry. Units of three different strengths (6, 12 and 24 MPa) and containing three different aggregate types (basalt, gneiss, and limestone) were tested. From results, it was observed that in less resistant blocks, the mixtures porosity influenced mechanical properties more than aggregate stiffness. As concretes become denser and stronger, this behavior changes. The models implemented and calibrated by the experimental results were satisfactory in reproducing the failure mode of the blocks, secant modulus and compressive strength results.

Keywords
Structural masonry; Hollow concrete blocks; Concrete aggregates; Mechanical properties; Computational modeling