Performance of Concrete with Waste Granite Powder: The Effect of Superplasticizers

Granite stone is highly demanded by construction sector. In the processing stage, great amounts of waste powder are produced that can be used as cement replacement in concrete production. Reduced workability is the first problem of this replacement and it can be mitigated by using superplasticizers (SP). This study was carried out to limit the disadvantages related to waste granite powder (WGP) use through the use of SP. For this purpose, 19 concrete mixes containing various types of SP with different contents and WGP as cement replacement were appraised. Fresh concrete density, splitting tensile strength, electrical resistivity, compressive strength and resistance to sulphate attack tests were conducted. The mixes were assessed based on their environmental impact, economic, and mechanical performance. The results have shown that SP can eliminate most disadvantages caused by using stone waste, particularly negative effects on the mechanical properties. They can even improve some properties of concrete, including electrical resistivity by up to around 90%. Furthermore, the concrete mixes PT5, PF5, and PF10, which were made with both SP and stone waste, obtained the best results, with over 30% improvement in the multi-criteria evaluation index values compared to the mix W0 (reference mix). The proper use of WGP as replacement for cement would have environmental benefits and help the economy of the granite stone industry.