Effect of ultrafine ground granulated blast-furnace slag (UFGGBFS) and copper slag on ambient cured geopolymer concrete

Abstract

This paper explores deep into the effects of mineral admixtures, e.g. ultrafine ground granulated blast-furnace slag (UFGGBFS) and copper slag (CPS), on ambient cured geopolymer concrete (GPC). First, a GPC was prepared from mineral admixtures like the UFGGBFS, fly ash and the CPS, and alkali activators like sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Then, 10M, 12M and 14M GPC samples were created, with UFGGBFS content of 0%, 5%, 10% and 15%, respectively. These samples were subjected to compressive strength tests, rapid chloride permeability test (RCPT), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the GPC samples achieved good compressive strength after 56 days of ambient curing; with the increase of the UFGGBFS content, the porosities and RCPT values of the samples decreased after 180 days of ambient curing; the samples with different mix ratios all showed good performance with the growth in molar concentration. The research results shed new light on the development of eco-friendly alternatives to cementitious GPC.