Mechanical and acoustic properties of fiber-reinforced alkali-activated slag foam concretes containing lightweight structural aggregates

This experimental study aimed to develop alkali-activated slag foam concretes with good acoustic properties for the indoor walls of residential buildings. Petrit-T, which is a by-product obtained in the manufacturing of sponge iron with a fine particle-size distribution and with rich calcium content, was used to prepare the structural lightweight aggregates. The produced lightweight structural aggregates were used in the preparation of alkali-activated slag binders, wherein ground granulated blast-furnace slag (GGBFS) as the binder was activated by an alkali solution. In the first stage of this study, the effects of using different types of fibers, including Polyvinyl alcohol (PVA), polypropylene (PP), and basalt, on the mechanical properties of alkali-activated slag binders were investigated. The mechanical properties were evaluated in terms of the compressive and flexural strengths. Thereafter, to achieve the best performing fiber reinforced alkali-activated slag concrete in terms of mechanical properties, the developed fiber-reinforced composition was used to generate alkali-activated slag foam concretes using different pre-made foam dosages (10, 15, 20, 25, 30, and 35% of the total binder mass). Finally, alkali-activated slag foam concretes were developed by varying the density in the range of 0.55–1.5 g/cm³; compressive strength in the range 2.5–13 MPa; and acoustic absorption coefficients higher than 0.5 in the medium-to-high frequency regions. Moreover, the density and acoustic properties were found to be linearly correlated.