Evaluation of the mechanical properties and durability of self-compacting alkali-activated mortar made from boron waste and granulated blast furnace slag

Abstract

The production of high-strength alkali-activated mortar and concrete by using waste materials instead of cement in order to reduce the amount of carbon dioxide released to nature in cement production is an important study that attracts the attention of researchers. In this study, self-compacting alkali-activated mortar samples were produced using boron waste (BW) and granulated blast furnace slag (GBFS). Prismatic samples of 40 × 40 × 160 mm and cubes of 50 × 50 × 50 mm were produced, in which 0%, 5%, 10%, 15%, 20%, 25% of BW were used. To achieve self-compacting alkali-activated mortar (SCAAM) slump-flow test method was conducted by per The European Federation of Specialist Construction Chemicals and Concrete Systems (EFNARC) guidelines. The samples prepared using Na2SiO3 (NS)/NaOH (NH) = 3.0 were exposed to oven curing at 60 °C and 100 °C for 3 days. The flexural and compressive strength (CS) values of 3, 28 and 90 days were obtained for the samples whose curing period was completed. According to the mechanical strength results, influence of capillary water absorption, porosity, water absorption and density and freeze-thaw from durability tests were carried out. After experimental tests, Scanning Electron Microscope (SEM) and Energy-dispersive X-ray Spectroscopy (EDS) images were utilized to determine microstructures of the samples. As a result of the study, it was determined that the highest strengths were obtained at the curing temperature of 60 °C. Also, it was seen that mechanical strengths and durability decreased with the increase in the BW ratio in the mixtures.