scholarly journals Evaluation of the Effect of Granite Waste Powder by Varying the Molarity of Activator on the Mechanical Properties of Ground Granulated Blast-Furnace Slag-Based Geopolymer Concrete

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 306
Author(s):  
Fatheali A. Shilar ◽  
Sharanabasava V. Ganachari ◽  
Veerabhadragouda B. Patil ◽  
Kottakkaran Sooppy Nisar ◽  
Abdel-Haleem Abdel-Aty ◽  
...  

Industrial waste such as Ground Granulated Blast-Furnace Slag (GGBS) and Granite Waste Powder (GWP) is available in huge quantities in several states of India. These ingredients have no recognized application and are usually shed in landfills. This process and these materials are sources of severe environmental pollution. This industrial waste has been utilized as a binder for geopolymers, which is our primary focus. This paper presents the investigation of the optimum percentage of granite waste powder as a binder, specifically, the effect of molar and alkaline to binder (A/B) ratio on the mechanical properties of geopolymer concrete (GPC). Additionally, this study involves the use of admixture SP-340 for better performance of workability. Current work focuses on investigating the effect of a change in molarity that results in strength development in geopolymer concrete. The limits for the present work were: GGBS partially replaced by GWP up to 30%; molar ranging from 12 to 18 with the interval of 2 M; and A/B ratio of 0.30. For 16 M of GPC, a maximum slump was observed for GWP with 60 mm compared to other molar concentration. For 16 M of GPC, a maximum compressive strength (CS) was observed for GWP with 20%, of 33.95 MPa. For 16 M of GPC, a maximum STS was observed for GWP, with 20%, of 3.15 MPa. For 16 M of GPC, a maximum FS was observed for GWP, with 20%, of 4.79 MPa. Geopolymer concrete has better strength properties than conventional concrete. GPC is $13.70 costlier than conventional concrete per cubic meter.

2021 ◽  
Vol 13 (2) ◽  
pp. 873
Author(s):  
Numanuddin M. Azad ◽  
S.M. Samindi M.K. Samarakoon

There has been a significant movement in the past decades to develop alternative sustainable building material such as geopolymer cement/concrete to control CO2 emission. Industrial waste contains pozzolanic minerals that fulfil requirements to develop the sustainable material such as alumino-silicate based geopolymer. For example, industrial waste such as red mud, fly ash, GBFS/GGBS (granulated blast furnace slag/ground granulated blast furnace slag), rice husk ash (RHA), and bagasse ash consist of minerals that contribute to the manufacturing of geopolymer cement/concrete. A literature review was carried out to study the different industrial waste/by-products and their chemical composition, which is vital for producing geopolymer cement, and to discuss the mechanical properties of geopolymer cement/concrete manufactured using different industrial waste/by-products. The durability, financial benefits and sustainability aspects of geopolymer cement/concrete have been highlighted. As per the experimental results from the literature, the cited industrial waste has been successfully utilized for the synthesis of dry or wet geopolymers. The review revealed that that the use of fly ash, GBFS/GGBS and RHA in geopolymer concrete resulted high compressive strength (i.e., 50 MPa–70 MPa). For high strength (>70 MPa) achievement, most of the slag and ash-based geopolymer cement/concrete in synergy with nano processed waste have shown good mechanical properties and environmental resistant. The alkali-activated geopolymer slag, red mud and fly ash based geopolymer binders give a better durability performance compared with other industrial waste. Based on the sustainability indicators, most of the geopolymers developed using the industrial waste have a positive impact on the environment, society and economy.


2020 ◽  
Vol 2 (3) ◽  
pp. 128-133
Author(s):  
Addepalli Mallinadh Kashyap ◽  
Tanimki Chandra Sekhar Rao ◽  
N.V.Ramana Rao

The utilisation of pozzolanic materials as the replacement to conventional cement material have the potentiality to mitigate the pollution caused by the émission of carbon based green house gases which are a main source for global warming problem. For every production of 1 ton of cement it was approximated that the emission of carbon based green house gases are about 1 ton. Keeping this in view, a new material called Geopolymer which was first coined by Davidovits has gained a lot of interest by the researchers. In this study, different molarity variations of NaOH in the order of 4M, 6M, 8M, 10M, 12M and 14M and also the blending of  mineral admixtures like Fly Ash and Ground Granulated Blast Furnace Slag with percentages (50%+50%) and the mechanical properties of normal M30 and high strength grade M70 binary blended Geopolymer concrete were studied after 28 days of ambient curing and were reported. The test results revealed that the effect of molar concentration of NaOH at 12 M is effective and the optimum replacement of mineral composition of source materials is (50%+50%) fly ash and ground granulated blast furnace slag.  


In this study, geopolymer concrete is prepared by using 100% Ground Granulated Blast furnace Slag (GGBS). Then the GGBS is replaced by Metakaolin from 0 to 25% with the variation of 5% for preparing the specimens. The activator solution consists of Sodium hydroxide of 12 Molarity and sodium silicate in the ratio of 1: 2.5. 550kg/m3 of GGBS is used in this study. A carboxylic based admixture called La Hypercrete S25 is added in the mix by 1% of the weight of GGBS to increase the workability. The studies conducted on the specimens are compression test, split tensile test and flexure test. For conducting the compression test, 54 concrete cubes of size 100mm x 100mm x 100mm are cast for testing at 7, 14 and 28 days. For splitting tensile strength, 54 concrete cylinders with 100 mm dia and 200 mm height are cast for testing at 7, 14 and 28 days. The flexure test specimens are beams of 500 mm length and 100mm x 100mm in cross section are cast. These are 54 in numbers .Specimens are cast by replacing the GGBS by Metakaolin in 5, 10, 15, 20 and 25%. All the specimens are cured for 7, 14 and 28 days and tested for compression, split tensile and flexure. The test results reveal that the strengths are gradually increasing for 5, 10 and 15% replacement of GGBS by Metakaolin and give the highest value for 20% in all the tests. It also shows further increased replacements reduces the test values. It proves that geopolymer concrete performs well in strength properties with GGBS and Metakaolin.


2021 ◽  
Vol 27 (10) ◽  
pp. 50-67
Author(s):  
Sarah Sameer Hussein ◽  
Nada Mahdi Fawzi

In order to implement the concept of sustainability in the field of construction, it is necessary to find an alternative to the materials that cause pollution by manufacturing, the most important of which is cement. Because factory wastes provide siliceous and aluminous materials and contain calcium such as fly ash and slag that are used in the production of high-strength geopolymer concrete with specifications similar to ordinary concrete, it was necessary for developing this type of concrete that is helping to reduce CO2 (dioxide carbon) in the atmosphere. Therefore, the aim of this study was to study the influence of incorporating various percentages of slag as a replacement for fly ash and the effect of slag on mechanical properties. This paper showed the details of the experimental work that has been undertaken to search and make tests the strength of geopolymer mixtures made of fly ash and then replaced fly ash with slag in different percentages. The geopolymer mixes were prepared using a ground granulated blast-furnace slag (GGBFS) blend and low calcium fly ash class F activated by an alkaline solution. The mixture compositions of fly ash to slag were (0.75:0.25, 0.65:0.35, 0.55:0.45) by weight of cementitious materials respectively and compared with reference mix of conventional concrete with mix proportion 1:1.5:3 (cement: sand: coarse agg.), respectively. The copper fiber was used as recycled material from electricity devices wastes such as (machines, motors, wires, and electronic devices) to enhance the mechanical properties of geopolymer concrete. The heat curing system at 40 oC temperature was used. The results revealed that the mix proportion of 0.45 blast furnace slag and 0.55 fly ash produced the best strength results. It also showed that this mix ratio could provide a solution for the need for heat curing for fly ash-based geopolymer.


Author(s):  
Jean Noël Yankwa Djobo ◽  
Dietmar Stephan

AbstractThis work aimed to evaluate the role of the addition of blast furnace slag for the formation of reaction products and the strength development of volcanic ash-based phosphate geopolymer. Volcanic ash was replaced by 4 and 6 wt% of ground granulated blast furnace slag to accelerate the reaction kinetics. Then, the influence of boric acid for controlling the setting and kinetics reactions was also evaluated. The results demonstrated that the competition between the dissolution of boric acid and volcanic ash-slag particles is the main process controlling the setting and kinetics reaction. The addition of slag has significantly accelerated the initial and final setting times, whereas the addition of boric acid was beneficial for delaying the setting times. Consequently, it also enhanced the flowability of the paste. The compressive strength increased significantly with the addition of slag, and the optimum replaced rate was 4 wt% which resulted in 28 d strength of 27 MPa. Beyond that percentage, the strength was reduced because of the flash setting of the binder which does not allow a subsequent dissolution of the particles and their precipitation. The binders formed with the addition of slag and/or boric acid are beneficial for the improvement of the water stability of the volcanic ash-based phosphate geopolymer.


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