Effect of Alkaline Activator, Water, Superplasticiser and Slag Contents on the Compressive Strength and Workability of Slag-Fly Ash Based Geopolymer Mortar Cured under Ambient Temperature
Geopolymer (cement-free) concrete is the most promising green alternative to ordinary Portland cement concrete and other cementitious materials. While a range of different geopolymer concretes have been produced, a common feature of these concretes is heat curing treatment which is essential in order to provide sufficient mechanical properties in the early age. However, there are several practical issues with the application of heat curing in large-scale structures. The purpose of this study is to develop cement-free concrete without heat curing treatment. Experimental investigations were carried out in two phases. In the first phase (Phase A), the optimum content of water, polycarboxylate based superplasticizer contents and potassium silicate activator in the mix was determined. In the second stage (Phase B), the effect of ground granulated blast furnace slag (GGBFS) incorporation on the compressive strength of fly ash (FA) and Slag based geopolymer mixtures was evaluated. Setting time and workability were also conducted alongside with compressive tests. The results showed that as the slag content was increased the setting time was reduced while the compressive strength was improved. The obtained compressive strength was in the range of 40-50 MPa for 50% slag replacement mixtures. Furthermore, the results indicated that increment of water and superplasticizer content resulted to retarding of the setting time and slight reduction of the compressive strength. The compressive strength of the examined mixes was considerably increased as potassium silicate content was increased.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1112069Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1965
 M. P. Malhotra VM, "High-performance, high-volume fly ash concrete: materials, mixture, proportioning, properties, construction practice, and case histories," 2nd ed. Ottawa: Supplementary cementing materials for sustainable development incorporated, pp. 1–124., 2005.
 P. Nath and P. K. Sarker, "Effect of GGBFS on setting, workability and early strength properties of fly ash geopolymer concrete cured in ambient condition," Construction and Building Materials, vol. 66, pp. 163-171, 9/15/ 2014.
 S. K. Nath and S. Kumar, "Influence of iron making slags on strength and microstructure of fly ash geopolymer," Construction and Building Materials, vol. 38, pp. 924-930, 1// 2013.
 N. K. Lee and H. K. Lee, "Setting and mechanical properties of alkali-activated fly ash/slag concrete manufactured at room temperature," Construction and Building Materials, vol. 47, pp. 1201-1209, 10// 2013.
 M. Chi, "Effects of dosage of alkali-activated solution and curing conditions on the properties and durability of alkali-activated slag concrete," Construction and Building Materials, vol. 35, pp. 240-245, 10// 2012.
 P. S. Deb, P. Nath, and P. K. Sarker, "The effects of ground granulated blast-furnace slag blending with fly ash and activator content on the workability and strength properties of geopolymer concrete cured at ambient temperature," Materials & Design, vol. 62, pp. 32-39, 10// 2014.
 L. K. Turner and F. G. Collins, "Carbon dioxide equivalent (CO2-e) emissions: A comparison between geopolymer and OPC cement concrete," Construction and Building Materials, vol. 43, pp. 125-130, 2013.
 G. S. Ryu, Y. B. Lee, K. T. Koh, and Y. S. Chung, "The mechanical properties of fly ash-based geopolymer concrete with alkaline activators," Construction and Building Materials, vol. 47, pp. 409-418, 2013.
 B. Joseph and G. Mathew, "Influence of aggregate content on the behavior of fly ash based geopolymer concrete," Scientia Iranica, vol. 19, pp. 1188-1194, 2012.
 J. Xie and O. Kayali, "Effect of initial water content and curing moisture conditions on the development of fly ash-based geopolymers in heat and ambient temperature," Construction and Building Materials, 2014.
 A.-O. S., "Durability of concrete incorporating GGBS activated by waterglass.," Constr Build Mater, vol. 22, p. 2059, 2008.
 B. Nematollahi and J. Sanjayan, "Effect of Superplasticizers on Workability of Fly Ash Based Geopolymer," pp. 713-719, 2014.
 P. J. Lloyd RR, van Deventer JSJ., "Microscopy and microanalysis of inorganic polymer cements. 1: remnant fly ash particles," J Mat Sci, vol. 44, pp. 608–19. , 2009.
 S. H. Guo X, Chen L, Dick WA. , "Alkali-activated complex binders from Class C fly ash and Ca-containing admixtures," J Hazard Mater vol. 173, pp. 480–6, 2010.
 v. R. A. Temuujin J, Williams R. , "Influence of calcium compounds on the mechanical properties of fly ash geopolymer pastes," J Hazard Mater, vol. 167, pp. 82–8., 2009.
 A. M. Rashad, "A comprehensive overview about the influence of different additives on the properties of alkali-activated slag – A guide for Civil Engineer," Construction and Building Materials, vol. 47, pp. 29-55, 10// 2013.
 J. Davidovits, Geopolymer Chemistry and Applications, 3 ed.: Geopolymer Institute, 2011, 2011.
 B. E. 450-1:, "Fly ash for concrete. Definition, specifications and conformity criteria," ed, 31 August 2012.
 C. P. D. Antenucci, G. Lorenzi, "Understanding and mastering coal fired ashes geopolymerisation process in order to turn potential into profit (GEOASH)," 2009.
 "BS EN 480-2:.Admixtures for concrete, mortar and grout. Test methods. ," in Determination of setting time., ed, 2006.
 B. Nematollahi and J. Sanjayan, "Effect of different superplasticizers and activator combinations on workability and strength of fly ash based geopolymer," Materials & Design, vol. 57, pp. 667-672, 5// 2014.
 R. Yu, P. Spiesz, and H. J. H. Brouwers, "Development of an eco-friendly Ultra-High Performance Concrete (UHPC) with efficient cement and mineral admixtures uses," Cement and Concrete Composites, vol. 55, pp. 383-394, 1// 2015.
 A. C109, "Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50-mm Cube Specimens).", ed, 2012.
 J. G. Jang, N. K. Lee, and H. K. Lee, "Fresh and hardened properties of alkali-activated fly ash/slag pastes with superplasticizers," Construction and Building Materials, vol. 50, pp. 169-176, 1/15/ 2014.
 P. Chindaprasirt, T. Chareerat, and V. Sirivivatnanon, "Workability and strength of coarse high calcium fly ash geopolymer," Cement and Concrete Composites, vol. 29, pp. 224-229, 3// 2007.
 P. R. Vora and U. V. Dave, "Parametric Studies on Compressive Strength of Geopolymer Concrete," Procedia Engineering, vol. 51, pp. 210-219, 2013.