Abstract

The Effluent Treatment Plant Sludge (ETPS) obtained from wire drawing industry has been used as a filler material in fly ash–slag based geopolymer. Argon Oxygen Decarburization (AOD) slag from steel making plant and Granulated Blast Furnace Slag (GBFS) from iron industry have been used for making two different blends. The work investigates the potential of ETPS as filler and the Role of AOD slag & GBFS in fly ash–slag–sludge (FA+AOD+ETPS & FA+GBFS+ETPS) blended geopolymer. The characterization of raw materials was done using Inductive Coupled Plasma (ICP) technique, Sieve analysis, and X–Ray Diffractometry (XRD). The alkaline activator used for the activation of the ternary blend was the combination of NaOH and Na–silicate. The concentration of NaOH and the ratio of Na–silicate to NaOH were fixed to 6 M and 0.33 respectively. The curing temperature and curing period used for geopolymer synthesis were 50 ºC and 24 h.GBFS based samples showed higher strength than AOD based samples. The compressive strength was in the range of 3.8 to 17.5 MPa. GBFS based samples showed better resistance towards acid attack than AOD based samples. The early geopolymerization were analyzed at 27 ºC using Isothermal Conduction Calorimetry (ICC). The results showed that GBFS based samples had an intense peak at a lower time than AOD based samples. The characterization of hardened geopolymer samples by XRD and SEM–EDAX revealed that the major reaction products are N–A–S–H, C–A–S–H or (N, C)–A–S–H and C–S–H gel.

Keywords

ETP sludge, fly ash–slag–sludge blended geopolymer, strength, durability, geopolymerization, microstructure, intense peak