Properties of geopolymer mortars derived from ground calcined perlite and NaOH solution

Abstract

This study presents the strength development and characterisation of geopolymer mortars containing finely ground calcined perlite (GCP) as a precursor which is activated with sodium hydroxide (NaOH) solution. For this purpose, mortar specimens were produced with CEN standard sand, GCP, water and NaOH. The specimens subjected to heat curing after 24 h from casting and kept at an ambient temperature until the day of testing. The unit weight, ultrasound pulse velocity, flexural and compressive strengths of the mortar specimens were obtained after dry curing. The experimental results revealed that the mechanical properties of the mortars improved as the curing period and heat-curing temperatures increase, as well as increasing the concentration of NaOH. In addition, the characteristics of the mortars were determined by SEM/EDS and XRD analyses. According to the experimental results, the compressive strength of 37 MPa were obtained, and it is concluded that GCP can be used in geopolymer mortars owing to its abundance and appropriate chemical composition.