Use of slag and hemp for enhancing the strength and durability properties of concrete

A case study

Abstract

Concrete is one of the most important components utilized in the building sector. The shrinkage of the concrete throughout the curing process could end up in microcracks. These cracks function as channels for fluids to infiltrate the concrete. Under optimal circumstances, the fluids within the concrete undergo various reactions that lower the pH of the concrete core, leaving the reinforcing bars susceptible to corrosion. The solution to these problems could be combining slag and hemp into concrete. Four mixes, namely conventional concrete (CC), hempcrete (M1), slag-integrated concrete (M2), and slag-integrated hempcrete (M3), were used to study mechanical properties, durability properties, and microstructure. The slag was substituted for the fine aggregates by 50%, and hemp was taken as 3% of the binder for the mixes. The study showed that the slag-integrated hempcrete was superior in strength and durability properties compared to the other mixes. Slag filled the pores in the hemp and aggregates, making them denser and stronger overall. The reduction in porosity enhanced the durability attributes even further. Moreover, the hemp improved the binding quality, which improved strength and friction. The FESEM images provided visual confirmation of the reduced permeability of the mix. The integration of slag and hemp into concrete results in a sustainable mix and could be a solution to the extraction of resources.