Properties of Foundry Sand, Ground Granulated Blast Furnace Slag and Bottom Ash Based Geopolymers under Ambient Conditions

This paper presents a feasibility study on the manufacture of geopolymer concrete at low concentrations of alkaline solutions and lower densities and incorporating waste products like Foundry sand without compensating for the strength properties. Ground Granulated Blast Furnace Slag (GGBFS) and Bottom ash (BA) were used as source materials. From the preliminary studies, the replacement of Foundry sand to Natural sand is taken as 50:50. The density range was taken as 1800 Kg/m3, 2000 Kg/m3, 2200 Kg/m3 and 2400 Kg/m3. Sodium Hydroxide(NaOH) and Sodium Silicate(Na2SiO3) were used as alkaline activators and the molarity of NaOH solution was reduced from 8M upto 4 M. The percentage ratio of BA-GGBFS was selected as 0, 25, 50, 75 and 100. The ratio of Alkaline liquid to Binder content was taken as 0.4 and the molar ratio of NaOH solution was kept as 1. The ratio of Sodium silicate solution to Sodium hydroxide was taken as 2. Ambient curing was adopted for all the mixes. The properties of Geopolymer concrete paver blocks such as Compressive strength, flexural strength and split tensile strength, water absorption, Acid attack and Water absorption were conducted as per IS 15658:2006. Test results show that satisfactory strength properties of geopolymer concrete using Foundry sand can be achieved even with lower concentrations of NaOH solution under ambient curing conditions. This would pave way for creating a greener environment by the efficient use of byproducts and waste materials in concrete

Development and assessment of cement and concrete made of the burning of quinary by-product

The aim of this study is to evaluate the usability of new cement (NC) made by the burning of quinary by-product to make commercial binders. Chemical analysis of the by-products and NC as well as X-ray diffraction (XRD) analysis of NC, fineness, density, consistency, and setting time of NC paste, and slump in addition to compressive strength (CS) and splitting tensile strength (STS) of NC concrete (NCC) were conducted. The results suggested that chemical composition of by-products is suitable to make NC binder. The NC contains Ca3SiO5, Ca2SiO5, Ca3Al2O6, and Ca3Al2FeO10. The particles passing through the 200 um Sieve were 56% compared with 52% for Portland cement (PC). The density of the of NC was similar to that of PC. The NC needed 48% more water than PC for normal consistency. The initial and final setting-time of NC was 105 min and 225 min respectively which is much higher than that of PC (15 and 45 min). The slump, compressive strength and splitting tensile strength were slightly lower for concrete containing NC compared with that pf PC concrete. Although the CS and STS of NCC are the lowest, the rate of the CS and STS gain of NCC is greater than that of PCC. It was concluded that NC is a viable alternative to PC for the production of greener concrete

RETRACTED: Feasibility Studies on Compressive Strength of Ground Coal Ash Geopolymer Mortar

PAPER RETRACTED May 10, 2016, by the general editor of Periodica Polytechnica, because of plagiarism. Plagiarized paper: V Revathi, R Saravanakumar and J Thaarrini, Effect of Molar Ratio of SiO2/Na2O, Na2SiO3/NaOH Ratio and Curing Mode on the Compressive Strength of Ground Bottom Ash Geopolymer Mortar. International Journal of Earth Science and Engineering, August 2014, pp. 1511-1516