scholarly journals Geopolymer Concrete under Ambient Curing

2021 ◽  
Author(s):  
M. Indhumathi Anbarasan ◽  
S.R. Sanjaiyan ◽  
S. Nagan Soundarapandiyan

Geopolymer concrete (GPC) has significant potential as a more sustainable alternative for ordinary Portland cement concrete. GPC had been introduced to reduce carbon footprints and thereby safeguarding environment. This emerging eco friendly construction product finds majority of its application in precast and prefabricated structures due to the special curing conditions required. Sustained research efforts are being taken to make the product suitable for in situ applications. The developed technology will certainly address the issues of huge energy consumption as well reduce water use which is becoming scarce nowadays. Ground Granulated Blast Furnace Slag (GGBS) a by-product of iron industries in combination with fly ash has proved to give enhanced strength, durability as well reduced setting time. This study investigates the effect of GGBS as partial replacement of fly ash in the manufacture of GPC. Cube and cylindrical specimens were cast and subjected to ambient curing as well to alternate wetting-drying cycles. The 28 day compressive strength, split tensile strength, flexural strength and density of GPC specimens were found. The study revealed increase in compressive strength, split tensile strength, density as well flexural strength up to 40 percent replacement of fly ash by GGBS.

Geopolymer is being widely used in the construction industry in the recent years. Ground Granulated Blast Furnace Slag (GGBS) based geopolymer concrete is the most suited for ambient curing conditions. It has been perceived that geopolymer concrete is brittle in nature. This brittleness could be reduced by the augmentation of fibers. The objective of this paper is to study the effect of incorporation of polypropylene fibers in Geopolymer Concrete. The various proportions of the ingredients of Geopolymer concrete were calculated from the B.V.Rangan mix design of Geopolymer Concrete. Based on the previous research works conducted by the author, optimum molarity of the sodium hydroxide solution to be used as a part of alkaline activator solution was taken as 13M. Polypropylene fibers were added to the matrix in the ratios from 0.1% to 0.6%. Cubical, Cylindrical and Prism Specimens were casted and subjected to ambient curing. Compaction factor test was performed to measure workability of fresh concrete and tests such as compressive strength test, split tensile strength test and flexural strength test were performed to assess the mechanical properties of hardened Fiber Reinforced Geopolymer Concrete. Tests were carried after curing period of 7days & 28 days and the results were tabulated. Being a low modulus fiber, the fiberposses a good post cracking behaviour and reduce the brittleness of the Geopolymer Concrete. The incorporation of polypropylene fibers increases the compressive strength and flexural strength initially and then decreases.


2016 ◽  
Vol 841 ◽  
pp. 1-6 ◽  
Author(s):  
Puput Risdanareni ◽  
Adjib Karjanto ◽  
Febriano Khakim

This paper describes the result of investigating volcanic ash of Mount Kelud as fly ash substitute material to produce geopolymer concrete. The test was held on geopolymer concrete blended with 0%, 25%, 50% and 100% fly ash replacement with volcanic ash. Natrium Hidroxide (NaOH) with concentration of 12 molar and Natrium Silicate (Na2SiO3) were used as alkaline activator. While alkali-activator ratio of 2 was used in this research. The physical properties was tested by porosity and setting time test, while split tensile strength presented to measure brittle caracteristic of geopolymer concrete. The result shown that increasing volcanic ash content in the mixture will increase setting time of geopolymer paste. On the other hand increasing volcanic ash content will reduce split tensile strength and porosity of geopolymer concrete. After all replacing fly ash with volcanic ash was suitable from 25% to 50% due to its optimum physical and mechanical properties.


The present study appraises the recitals of carboxylic acid- based admixture to increase concrete water tightness and self-sealing capacity of the cement and geopolymer concrete. Outcomes of the previous studies in particular, adding 1% by cement mass of the carboxylic polymer reasons for reduction in the water dispersion under pressure of 7-day wet cured concrete by 50% associated to that of the conforming reference concrete. At 7 days, M4 mix compressive strength is about 43.5% less than M3 mix. The compressive strength of M4 increases and is about 37.6% less than M3 mix at 28 days of curing. At 7 days, M4 mix split tensile strength is about 17.5% less than M3 mix (cement concrete with 0.45 w/c ratio). The split tensile strength of M4 declines and is about 42.3% less than M3 mix at 28 days of curing. The strength of the geopolymer concrete tends to increase as the time period increases due to the presence of fly ash in it. So it is expected that geopolymer concrete will give more strength than cement concrete in long term with the presence of carboxylic acid


2021 ◽  
Vol 30 (3) ◽  
pp. 464-476
Author(s):  
Haider Owaid ◽  
Haider Al-Baghdadi ◽  
Muna Al-Rubaye

Large quantities of paper and wood waste are generated every day, the disposal of these waste products is a problem because it requires huge space for their disposal. The possibility of using these wastes can mitigate the environmental problems related to them. This study presents an investigation on the feasibility of inclusion of waste paper ash (WPA) or wood ash (WA) as replacement materials for fly ash (FA) class F in preparation geopolymer concrete (GC). The developed geopolymer concretes for this study were prepared at replacement ratios of FA by WPA or WA of 25, 50, 75 and 100% in addition to a control mix containing 100% of FA. Sodium hydroxide (NaOH) solutions and sodium silicate (Na2SiO3) are used as alkaline activators with 1M and 10M of sodium hydroxide solution.The geopolymer concretes have been evaluated with respect to the workability, the compressive strength, splitting tensile strength and flexural strength. The results indicated that there were no significant differences in the workability of the control GC mix and the developed GC mixes incorporating WPA or WA. Also, the results showed that, by incorporating of 25–50% PWA or 25% WA, the mechanical properties (compressive strength, splitting tensile strength and flexural strength) of GC mixes slightly decreased. While replacement with 75–100% WPA or with 50–100% WA has reduced these mechanical properties of GC mixes. As a result, there is a feasibility of partial replacement of FA by up to 50% WPA or 25% WA in preparation of the geopolymer concrete.


2015 ◽  
Vol 754-755 ◽  
pp. 406-412 ◽  
Author(s):  
Puput Risdanareni ◽  
Januarti Jaya Ekaputri ◽  
Mohd Mustafa Al Bakri Abdullah

This paper describes the effect of alkaline activator ratio (Na2SiO3/NaOH) to mechanical properties of geopolymer concrete. The mechanical properties of geopolymer concrete were assessed by setting time, split tensile strength and porosity. Fly ash was used as a cement substitute, and trass used as filler. While, Natrium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) was applied as alkaline activator. In this study, NaOH concentration eight and ten molar with an alkaline activator ratio Na2SiO3/ NaOH by mass: 0.5, 1, 1.5, 2 and 2.5 were used. The test result showed that setting time, porosity and split tensile strength of geopolymer concrete were hardly influenced by NaOH concentration and the alkaline activator ratio. The alkaline activator ratio of Na2SiO3/NaOH has an optimum value at 2 and 2.5. Test result showed that the fastest setting time was 25 minute, the highest amount of closed porosity was 9.035 % and the highest split tensile strength was 2.86 MPa.


Abstract. Light-weight structures are widely used in the construction field. Light-weight fillers such as aggregates can be used to improve weightless structures. Generally, standard aggregates cannot be used to attain the desired weight for light-weight structures. To determine a light-weight filler, the aggregates are made by using fly-ash along with cement mortar. Fly ash was collected from the Mettur Thermal power plant. Cement and fly-ash were mixed in a concrete mixer in a proportion of 30:70 with a water-cement ratio of 0.3 and it is mixed until the pellets are formed. The aggregates are replaced at different percentages such as 0%, 10%, 20%, and 30% respectively to the coarse aggregate. The properties such as compressive strength, split tensile strength and flexural strength were taken. The maximum strength was attained at 30% of fly-ash aggregate with a compressive strength of 46.47 N/mm2, split tensile strength of 14.85 N/mm2 and flexural strength of 3.80 N/mm2.


Author(s):  
Mantu Kumar

Abstract: Among all the current construction materials, concrete occupies a unique position. Concrete is the most often utilised building material. Cement production emits CO2, which is harmful to the environment. One of the most crucial ingredients in concrete production is cement. Experiments were carried out to see how different percentages of Fly Ash and GGBS affected the mechanical qualities of M60 grade concrete. After 7, 14, and 28 days of curing, the compressive strength of concrete cubes with suggested replacement was determined. Compressive strength, split tensile strength, and flexural strength are all evaluated on the cubes, cylinders, and prisms. The primary goal of this study is to compare the fresh and hardened characteristics of M-60 grade control concrete with concrete prepared with varied ratios of fly ash and GGBS Keywords: GGBS, Fly Ash, Durability, Compressive Strength, Tensile Strength, Flexural Strength, Slum cone Test


Author(s):  
Ravande Kishore ◽  
Archana Penchala

The Paper describes the comprehensive experimental work carried out on M40 grade bacterial concrete containing fly ash. Two types of common soil bacteria namely, Bacillus Pasteruii and Bacillus Odysseyi with a concentration of 105 cells/ml have been used. The optimum cell concentration of bacteria was arrived at by studying its influence on compressive strength of cement mortar matrix. Fly ash of 10 % by weight of cement was used to partially replace OPC in the concrete mixture. The performance of M40 bacterial concrete containing fly ash was assessed by testing the standard specimen for compressive strength, flexural strength and split tensile strength at different ages of curing. Results of investigation indicate significant improvement in 28 days compressive strength in the range of 12% to 27%. Twenty eight days flexural strength and split tensile strength have also shown appreciable increase in the range of 4% to 14% and 11% to 24% respectively. In general, the results of investigation are encouraging and set in positive direction for use of Bacterial concrete in the construction sector during 21st century.


Jurnal CIVILA ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 197
Author(s):  
Herwina Rahayu Putri ◽  
Firman Paledung ◽  
Erniati Bachtiar ◽  
Popy Indrayani

Fly ash is a kind of trash that may degrade the quality of the air. As a result, it is critical that it be used as an ecologically beneficial material. Although cement is the most often used construction material, its manufacturing generates carbon dioxide, which may degrade air quality. The aim of this research was to evaluate the compressive strength and split tensile strength of self-compacting geopolymer concrete (SCGC) cured in seawater, as well as to compare SCGC with and without saltwater. In this research, a cylindrical specimen with a diameter of 10 cm and a height of 20 cm was utilized as the specimen. Fly ash is used in proportion to fine and coarse aggregates at a ratio of 1: 0.65: 1.5. Using a 0.4 activator to binder ratio. The molarity ranges utilized were 11 M, 12 M, 13 M, 14 M, and 15 M. Compressive strength and split tensile strength tests were conducted on 28-day-old concrete. The findings indicated that when the molarity of SCGC treated with seawater increased from 11 to 15 M, the compressive and split tensile strengths increased. Compressive strength values were greatest in SCGC treated at room temperature when an activator of 13 M was used, and compressive strength values dropped in SCGC treated at room temperature when an activator greater than 13 M was used


2019 ◽  
Vol 8 (2) ◽  
pp. 2682-2687

Based0on the results obtained from this study0,the following Conclusions seems to be valid. The increase0in percentage replacement of Fly Ash with Metakaoline from 0% to 10.00% causes increase in Slump value up to 5% and beyond that slump is decreased. This0shows workability is reducing as percentage of Metakaoline increased beyond 5%. Hence, 5% replacement of Fly ash with Metakaoline is suitable from workability0point of view. The increase in percentage replacement0of Fly ash with0Metakaoline from 0% to 5% causes increase in compressive strength of concrete from 17.6MPa to 22.6MPa. Further0increase in percentage replacement of Fly ash with Metakaoline from 5% to 10% causes decrease in the0compressive strength from 22.6MPa to 18.7MPa. Hence, 5.00% replacement of Fly Ash with Metakaoline is advisable from compressive strength point of view .The increase in percentage replacement of Fly ash with Metakaoline from 0% to 5% causes increase in0Split Tensile strength of concrete from 3.72MPa to 4.68MPa. Further0increase in0percentage replacement of Fly ash with Metakaoline from 5% to 10% causes decrease in the split Tensile strength from 4.68MPa to 3.94MPa. Hence, 5.00% replacement of Fly Ash with Metakaoline is advisable from Split Tensile strength point of view. The increase in percentage replacement of Fly ash with Metakaoline from 0% to 5% causes increase in0flexural strength of concrete from 3.0 MPa to 3.36 MPa. Further increase in percentage replacement of Fly ash with Metakaoline from 5% to 10% causes decrease in the flexural strength from 3.36MPa to 3.2MPa.Hence 5.00% replacement of fly ash with Metakaoline is advisable from flexural strength point of view.Finally,it can conclude keeping in view of the workability ,compressive strength ,split tensile strength and flexural strength in mind,5% replacement of fly ash with Metakaolin is recommended for use in GEO POLYMER CONCRETE (GPC).


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