Geopolymerization: Eco-efficient paste made with recycled concrete

Abstract

In the present investigation, pastes from recycled concrete powder (RCP) with a particle size of 75 µm (200 mesh) were alkaline activated at different concentrations of alkaline solution (AS) in the order of 4M, 6M, 8M and 10M NaOH, which were compared with a paste made with ordinary Portland cement (OPC). For the preparation of the specimens, a ratio of SA/ PCR = 0.18 was used, which were cured at room temperature for 24 hours, then the curing was continued in an oven at 40°C for 72 hours and later the curing was completed up to 7 days at room temperature. The PCR was obtained from the pulverized concrete specimens tested at the Composite Materials Laboratory of the School of Materials Engineering -UNT. With respect to the compressive strength (CR)