Preliminary Study of the Rheological and Mechanical Properties of Alkali-activated Concrete Based on Tungsten Mining Waste Mud
Abstract
The rheological properties of Portland cement (PC) concrete have been extensively studied and compared with those of alkali-activated concrete (AAC). This study discusses the effect of the liquid to solid ratio on the rheological and mechanical properties of AAM concrete, based on mining waste mud as the binder phase, and compares them with those of Portland cement concrete (PCC). The AAM concrete studied is a mix of coarse aggregate 6/15, two types of sand (finer and coarse sand), and a precursor. The precursor is a mix of 70% tungsten mining waste mud, 15% waste glass and 15% metakaolin. This mix was activated by a combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) and the PCC was a mix of the same aggregate but with cement as binder and water as a liquid. The activator/precursor ratio was studied 0.5, 0.52, 0.54, 0.56 and 0.58. The results obtained show a similar rheological behaviour between AAC and PCC, the workability affected by L/S increases with the increasing ratio L/S in AAC and for L/S=0.5 slump was 6 cm and was 16 cm for L/S =0.58. Regarding the mechanical properties, the results obtained in 7 days showed similar performance in AAC and PCC. The compressive strength also decreases with the increasing of L/S, in AAC with L/S=0.5 the compressive strength was 15.9 MPa and for L/S =0.58 was 10.5.
Keywords: Tungsten mining waste, Rheology, Mechanical properties, Portland cement, alkali-activated concrete
References
[1] European Parliament, Council Directive 2013/59/Euratom of 5 December 2013 laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation, and repealing Directives 89/618/Euratom, 90/641/Euratom, 96/29/Euratom, 97/43/Euratom a. Off J Eur Commun L13, (2014) 1–73. https://doi.org/doi:10.3000/19770677.L_2013.124.eng.
[2] Bignozzi, M. C. et al. (2014). Room temperature alkali activation of fly ash: The effect of Na 2O/SiO2 ratio. Construction and Building Materials, vol. 69, pp. 262–270.
[3] Hardjito R. B. V., Wallah S. E. and Sumajouw D.M.J. (2004). On the Development of Fly AshBased Geopolymer Concrete. ACI Materials Journal/November-December, vol. 101, No. 6, pp. 467–472.
[4] Castro-Gomes, J. P. et al. (2012). Potential for reuse of tungsten mining waste-rock in technical-artistic value added products. Journal of Cleaner Production, vol. 25, pp. 34–41.
[5] A. Palomo, et al. (2014). A review on alkaline activation: new analytical perspectives. Materiales de Construcción, vol. 64, No. 315.
[6] Provis, J. L., Palomo, A. and Shi, C. (2015). Cement and Concrete Research Advances in understanding alkali-activated materials. Cement and Concrete Research, vol. 78, pp.110–125.
[7] Shi, C., Jiménez, A. F. and Palomo, A. (2011). Cement and Concrete Research New cements for the 21st century: The pursuit of an alternative to Portland cement. Cement and Concrete Research, vol. 41, pp.750–763.
[8] Chindaprasirt, P. (2007). Workability and strength of coarse high calcium fly ash geopolymer. Cement and Concrete Composites, vol. 29, No. 3, pp. 224–229. https://doi.org/10.1016/j.cemconcomp.2006.11. 002.
[9] Silva, A., et al. (2011). Cement & Concrete Composites The effects of Na2O/SiO2 molar ratio, curing temperature and age on compressive strength, morphology and microstructure of alkali-activated fly ash-based geopolymers. Cement and Concrete Composites, vol. 33, pp. 653–660.
[10] Mingyu, H., Xiaomin, Z. and Fumei, L. (2009). Cement & Concrete Composites Alkali-activated fly ash- based geopolymers with zeolite or bentonite as additives. Cement and Concrete Composites, vol. 31, pp. 762–768.
[11] Tattersall G. H. and Banfill, P. F. G. (1983). The rheology of fresh concrete. (Pitman Advanced Publishing Programme).
[12] Krieger, I. M. and Dougherty, T. J. (1959). A Mechanism for Non-Newtonian Flow in Suspensions of Rigid Spheres. Transactions of the Society of Rheology, vol. 3, pp. 137–152.
[13] Ahmari, S. and Zhang, L. (2012). Production of eco-friendly bricks from copper mine tailings through geopolymerization. Construction and Building Materials, vol. 29, pp. 323–331.
[14] Feng-qing, Z. (2009). Autoclaved brick from low-silicon tailings. Construction and Building Materials, vol. 23, pp. 538–541.