Chemo-physico-mechanical characteristics of high-strength alkali-activated mortar containing non-traditional supplementary cementitious materials

Abstract

The effect of non-traditional cement replacement materials as a replacement in the ground granulated blast furnace slag (GGBS) - fly ash (FA) based alkali-activated mortar (AAM) was investigated. In AAM, GGBS was replaced with 20%, 30% and 40% of palm oil fuel ash (POFA), treated palm oil fuel ash (TPOFA), palm oil clinker powder (POCP) and bottom ash (BA) by weight. Microstructure of mortar was investigated using X-ray Diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). The significant parameters investigated include the microstructures, alkali-activated material's reactivity, setting behavior and mechanical properties following ASTM standard. The potential of the pozzolanic binder materials was evaluated from the Chapelle test. The results indicated that among all the non-traditional SCMs, TPOFA achieved a satisfactory performance in all the investigations conducted. In case of AAM, 30% replacement of GGBS with TPOFA attained the highest 28-day compressive strength of 82.45 MPa. The formation of C–A–S–H gel was identified in GGBS based AAM. The results obtained from this study revealed that the TPOFA based AAM can be consider as a novel alternative sustainable green and environmental friendly material. In addition, the use of 30% of pozzolanic cementitious material can be used to replace GGBS in the development of AAM to develop high strength AAM in the range of 60–100 MPa.