scholarly journals The effect of slag addition on strength development of Class C fly ash geopolymer concrete at normal temperature

2017 ◽  
Author(s):  
Arie Wardhono ◽  
David W. Law ◽  
Sutikno ◽  
Hasan Dani
Keyword(s):  
Fly Ash ◽  
Strength Development ◽  
Geopolymer Concrete ◽  
Class C

The ratio of alkali modulus in strength development of class c fly ash geopolymer mortar

2021 ◽  
Author(s):  
Arie Wardhono ◽  
Bambang Sabariman ◽  
M. Imaduddin ◽  
M. Firmansyah Sofianto ◽  
Ninik W. Hidajati ◽  
...  
Keyword(s):  
Fly Ash ◽  
Strength Development ◽  
Class C

Effect of Partial Replacement of Fly Ash by Metakaolin on Strength Development of Fly Ash Based Geopolymer Mortar

2017 ◽  
Vol 744 ◽  
pp. 131-135 ◽  
Author(s):  
Muhammad Zahid ◽  
Nasir Shafiq ◽  
Mohd Fadhil Nuruddin ◽  
Ehsan Nikbakht ◽  
Asif Jalal
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide Solution ◽  
Base Material ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Partial Replacement ◽  
Strength Development ◽  
Class C ◽  
Class F

This article aims to investigate the compressive strength variation by the addition of metakaolin as a substitute of fly ash in the fly ash based geopolymer mortar. Five, ten and fifteen percent by weight of fly ash was replaced by highly reactive metakaolin. Two type of fly ashes namely, ASTM class F and ASTM class C were used as a base material for the synthesis of geopolymer mortar. Eight molar sodium hydroxide solution mixed with sodium silicate solution was used as alkaline activator. For optimum geopolymerization, mortar was cured at sixty degree Celsius for twenty four hours duration. Results show different behavior of metakaolin replacement on compressive strength for two different types of fly ash based geopolymer mortar. Improvement in compressive strength was seen by addition of metakaolin in ASTM class F fly ash based geopolymer. On the other hand compressive strength was decreased abruptly in fly ash class C based geopolymer up to certain replacement level.

scholarly journals A study on the strength development of geopolymer concrete using fly ash

2017 ◽  
Vol 6 (4) ◽  
pp. 163 ◽  
Author(s):  
Ramesh Babu Chokkalingam ◽  
Ganesan N
Keyword(s):  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Sodium Hydroxide Solution ◽  
Fine Sand ◽  
Strength Development ◽  
Alkali Activation ◽  
Geopolymer Concrete ◽  
Water Contaminants ◽  
Significant Difference

Cement consumption is increasing day by day due to the tremendous development in the infrastructure facilities. The production of one ton of cement emits approximately one ton of carbon dioxide to the atmosphere. In order to reduce the use of cement a new-generation concrete has been developed such as geopolymer concrete (GPC).Geopolymer Geopolymer is a new material which has the potential to replace ordinary Portland cement. It is an inorganic material synthesized by alkali activation of amorphous aluminosilicates at ambient or slightly increased temperatures having an amorphous to semi-crystalline polymeric structure. In this study, low calcium flyash from Tuticorin was used to produce geopolymer concrete. The geopolymer was synthesized with sodium silicate and sodium hydroxide solutions. The sodium hydroxide pellets was dissolved in the distilled water to make free from mixing water contaminants. The ratio of sodium silicate and sodium hydroxide ratio was kept as 2.5. The concentration of sodium hydroxide solution is 12 Molarity (12M). Other materials used are locally available coarse aggregate and fine sand in surface dry condition. A polycarboxlate HRWRA La Hypercrete S25was used. Cubes of size 100mm were cast for six mix proportions of 450kg/m3 flyash+0.35W/B, 500 kg/m3 flyash+0.35W/B, 550kg/m3 flyash+0.35W/B, 450kg/m3 flyash+.0.40 W/B, 500kg/m3 fly ash+0.40W/B and 550kg/m3 flyash+0.40W/B. The specimens after casting in moulds were kept in oven at 60°C for 6 hours and left to air dry at room temperature and tested at 7 and 28 days. The test results revealed the compressive strength of 30 Mpa was achieved. There was not much significant difference in strength development at 28 days between the mixes due to the increase of flyash content. The microstructural images at 28 days revealed that there was not much difference in the microstructure due to the variation in flyash content from 450 kg/m3 to 550 kg/m3.

scholarly journals Effect of various parameters on the workability and strength properties of geopolymer concrete

2021 ◽  
Vol 309 ◽  
pp. 01102
Author(s):  
Nutakki Sai Ketana ◽  
V Srinivasa Reddy ◽  
M V Seshagiri Rao ◽  
S Shrihari
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Properties ◽  
Ash Content ◽  
Geopolymer Concrete ◽  
Alkaline Activator ◽  
Class C ◽  
Class F

In the present study, effect of various molarities of NaOH, various fly ash content and alkaline activator solution (AAS) / fly ash(FA) ratios on the workability of geopolymer concrete(GPC) are studied along with the effect of use of Na2SiO3/NaOH and K2SiO3/KOH as alkaline activator solutions and various fly ash contents on the compressive strength of geopolymer concrete mixes. Observations shows that both Na2SiO3/NaOH and K2SiO3/KOH gives better performance for different molar, AAS/FA and oxide ratios. Class C GPC has better performance than Class F GPC. It was found that the increase in molarity decreases workability of geopolymer concrete. Also, the workability increases with increase in fly ash (FA) content and AAS/FA ratio in geopolymer concrete. Compressive and split tensile strengths decrease with increase in fly ash content.

scholarly journals Effect of discontinuous curing and ambient temperature on the compressive strength development of fly ash based Geopolymer concrete

2018 ◽  
Vol 162 ◽  
pp. 02026 ◽  
Author(s):  
Bayrak Almuhsin ◽  
Tareq al-Attar ◽  
Qais Hasan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ambient Temperature ◽  
Rest Period ◽  
Positive Influence ◽  
Strength Test ◽  
Strength Development ◽  
Geopolymer Concrete ◽  
Compressive Strength Test ◽  
Compressive Strength Development

In the current study, 6 mixtures of Geopolymer concrete have been studied. The effect of discontinuous curing in oven and in atmosphere ambient temperature has been inspected by exposing the Geopolymer concrete specimens to temperature in the oven for few hours then stopping the oven to let it cool down to the ambient temperature. The compressive strength test of 100x200 mm cylindrical specimens for each mixture has been performed at different ages. It was found that the ambient temperature has vast effect on the compressive strength of the Geopolymer concrete in discontinuous curing. Discontinuous curing saves energy and can be a good replacement to the continuous curing when the ambient temperature is 40°C or more. Specimens that were cured continuously in ambient temperature of 43°C has resulted in compressive strength of 23 MPa at age of 40 days; to enhance the compressive strength, it is advised to impose few hours of discontinuous oven curing. It was also found that the rest period (starts when pouring concrete in forms and ends when imposing oven curing to the Geopolymer) has a positive influence on the compressive strength of Geopolymer concrete, but when no rest period is allowed, the later ages compressive strength is remarkably higher.

scholarly journals Effect of molarity of sodium hydroxide and molar ratio of alkaline activator solution on the strength development of geopolymer concrete

2021 ◽  
Vol 309 ◽  
pp. 01058
Author(s):  
V Srinivasa Reddy ◽  
Karnati Vamsi Krishna ◽  
M V Seshagiri Rao ◽  
S Shrihari
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Ash Content ◽  
Mix Design ◽  
Molar Ratio ◽  
Strength Development ◽  
Geopolymer Concrete ◽  
Synergic Effect ◽  
Alkaline Activator

In the current study, effect of SiO2/Na2O ratio in Sodium silicate (Na2SiO3) solution, Na2SiO3/NaOH ratio and molarity of NaOH on the compressive strength of geopolymer concrete. A geopolymer mix design is formulated with various mixes are casted with alkali activator solution (AAS) / fly ash (FA) =0.5 and constant fly ash content. The molar ratio of SiO2/Na2O in Na2SiO3 solution is altered from 1.50 to 3.00 for different ratios of Na2SiO3/NaOH (2.0, 2.5 and 3.0) and also for various molarities of NaOH (8M,10M,12M,14M,16M and 18M) are studied for their synergic effect on the compressive strength of geopolymer concrete. Results highlighted that the 16M NaOH yields high compressive strength when SiO2/Na2O in Na2SiO3 solution is around 2.00 to 2.40 and Na2SiO3/NaOH=2.5.

Discussion on Properties and Microstructure of Geopolymer Concrete Containing Fly Ash and Recycled Aggregate

2012 ◽  
Vol 450-451 ◽  
pp. 1577-1583 ◽  
Author(s):  
Xiao Shuang Shi ◽  
Qing Yuan Wang ◽  
Xiao Ling Zhao ◽  
Frank Collins
Keyword(s):  
Fly Ash ◽  
Carbon Dioxide Emission ◽  
Construction Materials ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Strength Development ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Alkali Activated

Construction materials dominate the main responsibility to maintain the environmental sustainable development in human’s activities. Geopolymer concrete containing fly ash and recycled aggregate is a new concrete which can reuse the by-product of power station and waste concrete, as well as reduce the production of cement which contribute a lot of carbon dioxide emission in the manufacturing process. In this paper, experiments were carried out to investigate the mechanical properties and microstructure of geopolymer concrete with different recycled aggregate contents. Six mixtures were designed including alkali-activated fly ash geopolymeric recycled concrete and corresponding ordinary concrete as the comparison. The compressive strength of the concrete with 0%, 50% and 100% recycled aggregates was tested. The microstructure of these concrete were investigated by petrographic microscope under transmit light. According to experimental results, the strength development and failure mechanism are discussed. Furthermore, the application of such geopolymer concrete is discussed and suggested.

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