Investigating porous concrete with improved strength: Testing at different scales

Porous concrete incorporates a high percentage of meso-size air voids that makes its mechanical characteristics remarkably different from normal concrete. A research project was undertaken to design a special type of porous concrete, that fractures into small fragments when exposed to impact loading while having sufficient static strength, to be used in protective structures such as safety walls or storages for explosives. In the concretes designed, while a sufficient static strength was required, high porosity was essential to facilitate the formation of multiple cracks and the subsequent fracturing. Production of porous concretes having improved static compressive strengths was accomplished by modifying the mixture design and the compaction technique; while the design procedure was supported by macro and meso-scale mechanical testing, computed tomography, microscopy and X-ray diffraction analysis.

► Porous concretes having improved static strengths were designed and investigated.
► Mechanical tests at different scales were conducted.
► Computed tomography, microscopy and XRD analysis supported the investigation.
► Compaction and aggregate properties have a dominant effect on mechanical properties.
► The contribution of silica fume to the mechanical properties was not significant.