Comprehensive Study on Alkali Activated Blast Furnace Slag – Metakaolin Based Geopolymer Cement

Abstract

The characterization of alkali activated cement prepared by blending blast furnace slag (BFS) and metakaolin (MKa) were studied. MKa of particle size 45, 125 μm and blain area 6530, 2245 cm2/gm, respectively were used as 0, 20, 40, 60 and 80% replacement of BFS in the production of alkali activated cement. The utilized alkaline activator was mixture of NaOH and Na2SiO3 with various molar ratios. The prepared specimens were cured under two curing conditions; in 100% humid and air curing conditions up to 90 days. All specimens were characterized regarding setting times, compressive strength and water absorption. The formed hydrates were studied using XRD analysis, FTIR spectroscopy and SEM technique. The durability of the prepared geopolymer was determined via studying the fire resistance at 300, 600 and 800 oC and sulfate ions attack after time intervals extended up to 1 year. The results indicated that the specimens made from 60% BFS and 40% MKa and activated by (1:1) NaOH and Na2SiO3 were revealed the best overall behavior.