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Ghosh, Partha
- Comparative Study on Durability of Fly Ash Based Geopolymer Mortars in Sulphuric Acid and Nitric Acid
Authors
1 Department of Construction Engineering, Jadavpur University, Jadavpur, IN
2 ITD Cementation India Limited, Kolkata, IN
Source
International Journal of Technology, Vol 5, No 2 (2015), Pagination: 164-168Abstract
Geopolymers are a new promising binder manufactured by activation of a solid alumina silicate source material with a highly alkaline activating solution. Every year a huge amount of Fly ash is obtained from thermal power stations which is rich in silica and alumina and hence can be used with an alkaline fluid (mixture of Na2SiO3 and NaOH is used here) as a substitute of Cement. The process of hardening of the paste consists of formation of three dimensional polymeric chain and hydration does not take place in this case. So emission of CO2 is very less in this case. An experimental study was conducted to study and compare the durability or acid resistance of fly ash based geopolymer mortar exposed to Nitric and Sulphuric acid. Compressive strength, weight of specimens and pH of acid solution is recorded at a regular interval. Residual alkalinity is tested at a regular interval by using 1% Phenolphthalein solution. The results are recorded and compared. Results obtained in the present study indicate that Geopolymers are highly resistant to both Sulphuric and Nitric acid.
Keywords
Geopolymers, Residual Alkalinity, pH, Residual Compressive Strength.
- DIN Permeability Test and Effect of Concentration of Alkali on the Water Penetrability of Geopolymer Mortar
Authors
1 Department of Construction Engineering, Jadavpur University, Jadavpur, IN
2 ITD Cementation India Limited, Kolkata, IN
Source
International Journal of Technology, Vol 5, No 2 (2015), Pagination: 177-180Abstract
This paper represents the experimental investigation done on the permeability characteristics of geopolymer paste. The geopolymer mortar is made by using class F fly ash and Zone 3 sand. The alkali activator fluid used is the mixture of Sodium Silicate (Na2SiO3) solution and Sodium Hydroxide (NaOH) solution. Samples having dimensions 150mm*150mm*150mm with varying fluid to fly ash ratio and concentration of the alkali in the solution were prepared. After casting, the samples were kept in room temperature until 28 days DIN 1048 part 5, 1991 Permeability Test and Ultrasonic Pulse Velocity Test conducted on the specimens. The variations in water permeability and ultrasonic pulse velocity for samples with variation in fluid to fly ash ratio are observed. An effort is made to draw the interlink between UPV test results and permeability test results and their significance in identifying the quality and water penetrability of geopolymer paste.