INVESTIGATION OF THE RECYCLED CONCRETE FINES AS A MINERAL ADDITIVE FOR CONCRETE

Abstract

This research investigates the potential of utilizing the recycled concrete fines (RCF) as a partial replacement for Portland cement in concrete production.  The study addresses the growing concern of construction and demolition waste management, particularly in the context of Ukraine's post-war reconstruction and alignment with European Union environmental regulations (specifically, Regulation (EU) 2024/1159).   

The research focuses on the influence of key concrete mix parameters on workability and compressive strength.  These parameters include the water-cement ratio (W/C), the percentage of cement replaced by the RCF (<0.3 mm), and the dosage of superplasticizer (SP). A designed experiment approach was employed to analyze the effects of these factors. The results of the study are presented through regression models that describe the relationships between the mix parameters and concrete workability and strength (at 3 and 28 days).  The findings indicate that the W/C ratio is the most influential factor on compressive strength, while the superplasticizer dosage primarily affects workability.  Notably, replacing up to 10-15% of cement with the RCF does not significantly compromise strength and has a limited impact on workability.  The research also reveals an interaction between factors, where the effect of RCF is more significant at higher W/C ratio.   

This research contributes to the development of sustainable concrete production methods by providing valuable insights into the effective utilization of recycled concrete waste.  The findings support efforts to reduce reliance on virgin materials, minimize waste, and promote circular economy principles within the construction sector, particularly in the context of reconstruciton efforts and adherence to evolving environmental standards.