An Experimental Investigation of Hydraulic and Early and Later-Age Mechanical Properties of Eco-Friendly Porous Concrete Containing Waste Glass Powder and Fly Ash

Abstract

Porous concrete (PC) is a special concrete that contains interconnected large voids, unlike traditional concrete. Coarse aggregate and a minimal fine aggregate are used in the PC composition, thus providing more air and water permeability than conventional concrete. Thanks to the high permeability feature of PC, the natural water cycle is preserved, and rainwater meets groundwater. However, since PC is porous due to its cavity structure, its compressive strength is generally lower, and its durability properties are weaker than conventional concrete. Although fly ash (FA) and waste glass powder (WGP) adversely affect the permeability properties of PCs, they can significantly improve their strength and durability properties. This study examined the effects of FA and WGP on PC's hydraulic and mechanical properties. As a result of the study, we obtained FA- and WGP-added PC samples' hardened density (HD), apparent porosity (AP), water permeability coefficient (k), compressive, splitting tensile, and flexural strengths. The image analysis was also used to determine the FA- and WGP-added PC sample's gap sizes. According to the results obtained, the FA and WGP filled the gaps in the interior structure of the PC by showing a filler effect and, as a result, reduced the AP and k values of the PC. However, FA and WGP significantly increased the compressive, splitting tensile and flexural strength capacities of PC, especially in older ages, due to the progression of hydration, thanks to the calcium-silicate-hydrate (C-S-H) bonds they constituted in the PC matrix and their high pozzolanic activities. © 2024 Elsevier Ltd