Production Of Geopolymer Concrete Research Articles

Taguchi optimization of geopolymer concrete produced with rice husk ash and ceramic dust.

Metakaolin, fly ash, and mostly granulated blast furnace slag (GBFS) are traditionally used in the production of geopolymer. This study, adding to the knowledge base on geopolymer concretes as an alternative to cement mixtures, explored an experimental approach that investigates the use of ceramic dust (CD) and rice husk ash (RHA) with high SiO content instead of GBFS in the production of geopolymers. For this purpose, instead of GBFS, RHA at proportions of 0, 5%, 10%, and 15% and CD at proportions of 0, 10%, 20%, and 30% were used in the production of geopolymer concrete. In addition, groups were determined with a Taguchi L16 matrix with NaOH (an important material in geopolymer production) at 12, 14, 16, and 18 molality. Varying combinations of flow diameter, density, porosity, and water absorption rate were used, and their performance under high temperatures in terms of compressive strength was evaluated. The use of RHA in geopolymer concretes produced using CD and RHA had a negative effect on the flow and water absorption rates. However, the use of CD had a positive effect, and geopolymer concretes with high density and porosity were obtained. In addition, it was determined that strengths > 70MPa could only be obtained if 5-20% CD were used at 14-16 molality. The resistance of geopolymer concretes to high temperatures is lower than normal concretes. However, when comparing RHA and CD, it was determined that the use of CD would be more effective on geopolymer materials, and special measures should be taken at temperatures > 450°C.

Assessment of strength and abrasion resistance of elasto-plastic fiber reinforced concrete using geopolymer based recycled aggregates

Recycled aggregates and geopolymer binders are green materials contributing to the sustainability of the planet. We investigated the performance of geopolymer concrete using recycled aggregates (fly ash (FA) and ground granulated blast furnace slag (GGBS)) related to their mechanical properties. Geopolymer concrete were prepared by mixing 50% low calcium fly ash, 50% GGBS, sodium hydroxide and sodium silicate solution, Coarse aggregate (Natural coarse aggregate, Recycled coarse aggregate), Fine aggregate (Crushed Sand, Riverbed Sand) and elastoplastic fibers. Recycled aggregate used was obtained locally from Istanbul, Turkey. To explore the efficiency of recycled aggregate, during the production of geopolymer concrete, partial replacement of recycled coarse aggregate with natural aggregate was made in 10, 20, 30, and 40%. To compare the results, geopolymer concrete containing 100% natural aggregates was made. Since concrete gains strength with time after casting, On Day-28 and Day-90, the compressive strength, split tensile strength, and flexural strength of those geopolymer based concrete were examined. Results of the test showed that the compressive strength of 28 and 90 days w.r.t. different ratios was 26.8, 25.3, 24.2, 23.1, 23 MPa, and 30.2, 28.1, 27.0, 25.2, 25.0, 23.0 Mpa respectively, while split tensile strength was 1.9, 1.5, 1.5, 1.4, 1.4 MPa and 2.0, 1.9, 1.9, 1.6, 1.5 MPa respectively, and the ultimate flexural strength of tested beams were in the range of 3.53 to 4.54 MPa. Although the general performance of the produced samples was showing a decrement with the increasing ratio of recycle aggregates, the obtained results indicated that using recycled aggregate is up to some extent of 30% is beneficial in terms of strength.

Effect of binder content and recycled concrete aggregate on freeze-thaw and sulfate resistance of GGBFS based geopolymer concretes

The use of waste materials in concrete production is important because of the recycling of these materials. In this context, the use of both geopolymer binder and recycled concrete aggregate (RCA) becomes important. For this purpose, in this study, ground granulated blast furnace slag (GGBFS) based geopolymer concrete containing RCA was designed and freeze–thaw (F-T) and sulfate resistance of these samples were determined. In the production of geopolymer concrete, three different binder contents (300, 400 and 500 kg/m3) and five different ratios of RCA (0, 25, 50, 75 and 100%) were used. Samples that completed curing period were exposed to 100F-T cycles and two sulfate solutions (3% MgSO4 and 1.5% Na2SO4 + 1.5% MgSO4). Compressive strength, ultrasonic pulse velocity (UPV), weight change and sorptivity values ​​of these samples were determined. At the same time, these results were interpreted together with microstructure analysis (SEM and EDS). An exponential relationship was found between Ca/Si and Si/Al ratios of the samples and their compressive strength. Increasing in Ca/Si ratio and decreasing in Si/Al ratio caused an increase in compressive strength. As the binder content amount increased, the resistance of the samples against F-T cycles and sulfate solutions increased. With the increasing RCA ratio in the samples, there were increases in strength losses, but these losses were low and indicated that RCA was suitable for use in geopolymer concrete production.

Behavior of Quarry Rock Dust, Fly Ash and Slag Based Geopolymer Concrete Columns Reinforced with Steel Fibers under Eccentric Loading

Geopolymer concrete, also known as an earth-friendly concrete, has been under continuous study due to its environmental benefits and a sustainable alternative to conventional concrete construction. The supplies of many source materials, such as fly ash (FA) or slag (SG), to produce geopolymer concrete (GPC) may be limited; however, quarry rock dust (QRD) wastes (limestone, dolomite, or silica powders) formed by crushing rocks appear virtually endless. Although significant experimental research has been carried out on GPC, with a major focus on the mix design development, rheological, durability, and mechanical properties of the GPC mixes; still the information available on the structural behavior of GPC is rather limited. This has implications in extending GPC application from a laboratory-based technology to an at-site product. This study investigates the structural behavior of quarry-rock-dust-incorporated fiber-reinforced GPC columns under concentric and eccentric loading. In this study, a total of 20 columns with 200 mm square cross-section and 1000 mm height were tested. The FA and SG were used as source materials to produce GPC mixtures. The QRD was incorporated as a partial replacement (20%) of SG. The conventional concrete (CC) columns were prepared as the reference specimens. The effect of incorporating quarry rock dust as a replacement of SG, steel fibers, and loading conditions (concentric and eccentric loading) on the structural behavior of GPC columns were studied. The test results revealed that quarry rock dust is an adequate material that can be used as a source material in GPC to manufacture structural concrete members with satisfactory performance. The general performance of the GPC columns incorporating QRD (20%) is observed to be similar to that of GPC columns (without QRD) and CC columns. The addition of steel fibers considerably improves the loading capacity, ductility, and axial load–displacement behavior of the tested columns. The load capacities of fiber-reinforced GPC columns were about 5–7% greater in comparison to the CC columns. The spalling of concrete cover at failure was detected in all plain GPC columns, whereas the failure mode of all fiber-reinforced GPC columns is characterized with surface cracking leading to disintegration of concrete cover.

Evaluate Effect Of Temperature On mechanical properties of Geopolymer Concretes blast furnace slag by using nanosilica and polyolefin fiber

Cement production has always been associated with environmental challenges due to carbon dioxide emissions. On the other hand, cement production is an energy-intensive process and leads to the consumption of abundant fossil fuels. In order to solve this problem, the production of geopolymer concrete is on the agenda. The researchers decided to reduce the negative effects of cement production and have superior properties than ordinary concrete . Geopolymer cement matrix, due to the production of abundant hydrated gels, has a higher density and cohesion than the Portland cement matrix, and this is the main reason for increasing the resistance of this type of concrete to high heat compared to ordinary concrete. In this study, the effect of heat on the mechanical properties of slag geopolymer concrete containing 0 to 8% nanosilica and 1 to 2% polyolefin fibers at 90 days of processing age was investigated and XRF, XRD and SEM experiments were used to study the microstructure. In the optimal design of slag geopolymer concrete (containing 8% nanosilica and free of fibers), we saw a decrease of 8 and 44% in the values after and before heating in compressive strength tests and determination of ultrasonic pulse speed of concrete, while in control concrete, the results decreased Reached 38 and 37 percent. In slag geopolymer concrete containing 8% nanosilica and 2% fibers, tensile strength and modulus of elasticity equal to 14 and 34% showed results after and before heating, for control concrete these figures decreased by 51 and 59% in the results. Received, the results of the falling hammer impact test also had a reduction in the resistance of heat-exposed concrete to hammer blows. In the end, the microstructural studies were in overlap and in coordination with the results of the tests of this study.

Use of waste paper ash or wood ash as substitution to fly ash in production of geopolymer concrete

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.

Sustainable use of polypropylene fibers and palm oil fuel ash in the production of geopolymer concrete

Geopolymer concrete is an innovative advance in the world, in this concrete cement is fully substituted with pozzolanic materials like fly ash and GGBS. In this present study fly ash is replaced with POFA (Palm oil fuel ash) up to 25% (0%,5%,10%,15%,20%,25%), 10% of stone dust is replaced with sand. In addition to the above materials, 0.2% of polypropylene fibers were added to the volume of concrete. 2.5 ratio of sodium silicate and sodium hydroxide solutions are added as Alkali activators for 10M molarity. Initially, the specimens are oven cured 80° C for about 24hrs and after that leave for ambient curing. All the specimens stood tested after 7 and 28 days of ambient curing. The prepared POFA based geopolymer was tested for all types of mechanical properties, like compressive strength, split tensile strength, bending strength and load deflection curve. All these properties are compared with the nominal concrete.

Experimental Investigation on Bagasse ash Based Geopolymer Concrete Subjected to Elevated Tempreture

Geopolymer in recent years is being deemed as a promising alternative to cement concrete, which has remained as backbone of the construction industry. Despite GPC having potential capability of reducing carbon footprint, still many of its characteristics and mechanism to be investigated. The present study represents the utilization of bagasse ash in the production of geopolymer concrete. In order to reduce the ecological imbalance by the emission of CO2 from cement production an attempt has been made to investigate the feasibility of utilizing sugar cane ash as one of the candidate in polymer concrete by maintaining different molar concentration of sodium based alkali activated solutions. Geopolymer concrete has been casted and assessed for the fresh and harden properties. In the present work sugar cane bagasse ash replacement was done partially from 10% to 100% to determine workability and strength parameters. The objective of the work is to find the maximum extent of bagasse ash by reducing GGBS & also to check the suitable silica content. GGBS has been used as a binder materials & to reduce the limitations of GPC with respect to workability, Aura mix super plasticizer has been used. While comparing the results with regular concrete after 28days sun curing shows the positive effect with maximum 30% bagasse ash further increment results in decrease in harden properties such as ultimate compressive strength, flexural strength and split tensile strength. specimens were subjected to the elevated temperature to study the properties of geopolymer concrete such as residual strength, mass loss.

Sustainable Asphalt Concrete for Road Construction and Building Material

In this study, the possibility of producing new geopolymer concrete from olive oil waste in Jordan is presented. Olive oil residues in Jordan and many Mediterranean countries constitute a major environmental and health problem. So far, the waste is disposed of by means of sanitary landfill, and this poses an environmental risk and pollutes the groundwater, the main source of water in Jordan. The ash remaining from burning olive oil residues was used to produce geopolymer concrete by adding sodium hydroxide and without using any Portland cement. Mixtures were prepared using the central composite design. The focus was on the two most important factors affecting the properties of geopolymer concrete, which is the amount of ash and the amount of alkaline solution. After curing the concrete and passing 28 days, the compressive strength, slump, absorption, and porosity were measured. The Results of compressive strength, absorption and porosity was excellent in comparison with the results obtained from conventional concrete. Despite the promising results the slump of the proposed concrete is low, and the slump loss was very fast. Further studies are needed to improve the workability of geopolymer concrete from olive oil waste. This concrete allows to recycle a large amount of olive waste in Jordan and many other countries which reduce the impact on health and environment.

Potential Use of Sillimanite Sand in Sustainable Geopolymer Concrete Production

Geopolymer concrete is reported as the best possible alternative to cement-based concrete. However, the limitation in the attainment of structural strength using ambient curing has restricted the use of geopolymer concrete for cast-in-situ construction. Therefore, the present study aims to develop ambiently cured geopolymer concrete using sillimanite sand as a replacement for river sand. The strength, durability, and microstructural properties of this concrete are evaluated. In the investigation, the fine aggregates of geopolymer concrete were replaced with 25%, 50%, 75%, and 100% sillimanite sand by weight. The test results revealed that the 8-M and 16-M molarity levels are feasible to attain the structural strength. Specifically, the 16-M molarity level with 50% replacement of fine aggregate with sillimanite sand exhibited higher geopolymerization. The suggested range of optimum replacement levels of fine aggregate with sillimanite sand is 25%–50%. An increase in percentage replacement beyond 50% indicates a reduction in compressive strength and durability properties. The microstructural analysis indicates dense interconnection between the gel networks due to the presence of sillimanite sand, uniform distribution of elements in the mix, and the presence of strong Na–Al–Si gel. The sillimanite-sand-containing geopolymer concrete developed using ambient curing resulted in a sustainable product along with higher mechanical and durability property.

An Experimental Investigation on Geopolymer Concrete Utilising Micronized Biomass Silica and GGBS

In the atmosphere greenhouse gases concentration has rapidly increased due to anthropogenic activities which cause global warming. Portland cement manufacturing process requires enormous amount of energy and also consumes huge quantity of natural resources. To overcome this issue, Portland cement free geopolymer concrete is produced with ground granulated blast furnace slag (GGBS) as main binder and micronized biomass silica (MBS) is substituted in place of GGBS at different quantities. Experimental investigation highlighting mechanical properties and durability performance of geopolymer concrete mixes produced with GGBS and MBS are presented here. Rice husk is used in the manufacture of MBS. Compressive, flexural, split tensile strength, elastic modulus and durability parameters like water absorption, sorptivity, rapid chloride permeability test were conducted. Geopolymer concrete mix with 20 percent MBS and remaining GGBS as binder was found to have optimal strength and durability performance. However, the compressive strength was above the target design strength for all the geopolymer concrete mixes. This experimental investigation vindicates the feasibility of utilizing MBS as a binder raw material in geopolymer concrete production.

Comparison of Hook and Straight Steel Fibers Addition on Malaysian Fly Ash-Based Geopolymer Concrete on the Slump, Density, Water Absorption and Mechanical Properties.

Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.

Application of Gene Expression Programming (GEP) for the Prediction of Compressive Strength of Geopolymer Concrete.

For the production of geopolymer concrete (GPC), fly-ash (FA) like waste material has been effectively utilized by various researchers. In this paper, the soft computing techniques known as gene expression programming (GEP) are executed to deliver an empirical equation to estimate the compressive strength of GPC made by employing FA. To build a model, a consistent, extensive and reliable data base is compiled through a detailed review of the published research. The compiled data set is comprised of 298 experimental results. The utmost dominant parameters are counted as explanatory variables, in other words, the extra water added as percent FA (), the percentage of plasticizer (), the initial curing temperature (), the age of the specimen (), the curing duration (), the fine aggregate to total aggregate ratio (), the percentage of total aggregate by volume (), the percent SiO2 solids to water ratio () in sodium silicate (Na2SiO3) solution, the NaOH solution molarity (), the activator or alkali to FA ratio (), the sodium oxide (Na2O) to water ratio () for preparing Na2SiO3 solution, and the Na2SiO3 to NaOH ratio (). A GEP empirical equation is proposed to estimate the of GPC made with FA. The accuracy, generalization, and prediction capability of the proposed model was evaluated by performing parametric analysis, applying statistical checks, and then compared with non-linear and linear regression equations.

Performance evaluation of sustainable geopolymer concrete produced from ferrochrome slag and silica fume

The main intention of this research is to reuse the industrial by product ferrochrome slag and silica fume as a partial replacement of natural coarse aggregate and fly ash, respectively for the production of Geopolymer concrete with improved mechanical properties. Natural coarse aggregate was replaced by ferrochrome slag (FS) in varying percentages from 0 to 40% by weight. Fly ash was replaced by silica fume (SF) at different percentages 0 to 15% by weight. The combined effect of FS and SF was studied by developing Geopolymer concrete. Tests for compressive strength, splitting tensile strength and flexural strength of the GPC have been carried out at 7, 28 and 90 days of curing. The scanning electron microscope (SEM) was performed for the inspection of surface texture of the microstructure of the hardened samples. X-ray diffraction (XRD) was conducted to investigate the crystallinity of the mineral phases of the material as well as the activation product. Fourier transformed infrared spectroscopy (FTIR) was carried out to know the degree of polymerization of the samples. At 28 days, compressive strength, splitting tensile strength and flexural strength of GPC produced by replacing 30% FS and 10% SF increases by 38.9%, 47% and 20.4% respectively. Acronyms: CS Compressive strength; FS Ferrochrome slag; NCA Natural coarse aggregates; NFA Natural fine aggregates.

Valorization of Geothermal Silica and Natural Bentonite through Geopolymerization: A Characterization Study and Response Surface Design

Geothermal silica is a potential source of amorphous silica for producing geopolymer concrete. The valorization of geothermal silica as a geopolymer concrete provides an opportunity for an added value to the geothermal-based power industry. In

A Critical Review of Waste Glass Powder as an Aluminosilicate Source Material for Sustainable Geopolymer Concrete Production

Incorporation of the waste glass powder (WGP) as an aluminosilicate precursor material in the geopolymer concrete preparation has been researched for the past twenty years as an alternative to the sustainable construction material because of its significant impact on the reduction of greenhouse gases. This paper reviews the various applications of the WGP in the geopolymer matrix production as binary and ternary source material and the impact of the inclusion of WGP on the fresh and hardened characteristics of geopolymer concrete. More research articles associated with the usage of WGP in geopolymer concrete were published in the last ten years. Collective information on the WGP as an aluminosilicate source material in binary, ternary and quaternary blended geopolymer concrete is not available. This review article sums up the newest findings and developments achieved in the synthesis of geopolymer concrete containing WGP as one of the aluminosilicate source material. The study concludes that WGP could be utilized as an innovative and promising eco-friendly aluminosilicate source material to manufacture geopolymer concrete, thereby providing an environmentally eco-friendly solution for the glass and Portland cement based industries.

Effect of high temperatures on mechanical, radiation attenuation and microstructure properties of heavyweight geopolymer concrete

Heavyweight geopolymer concrete (HWGC) is a new concrete type that combines the benefits of geopolymer concrete (GC) and heavyweight concrete. HWGC can be used to produce particular properties such as high radiation shielding, and mass concrete elements. HWGC based on fly ash and ground granulated blast furnace slag, using electric arc furnace steel slag (EAFSS), barite and ilmenite coarse aggregates can substantially have higher specific gravities than concrete made with crushed dolomite. In the experimental work carried out on four main groups, 13 GC mixes are prepared by using heavyweight coarse aggregates (HWCAs) at volume ratios of 0%, 25%, 50%, 75% and 100%. Fresh and mechanical properties, compressive and tensile strengths, and influence of high temperature on radiation are investigated for specimens subjected to high temperatures of up to 900oC for 1, 2 and 3 hours. Moreover, the internal structure of geopolymer is analyzed using scanning electron microscope and energy-dispersive X-ray. Results show a good effect of HWCAs on the properties, radiation shielding and unit weight. The density of heavyweight geopolymer mixes ranges between 2,415 and 3,480 kg/m3, and HWCA ratios contribute to an increase in all properties of GC mixtures using up to 75% of NWCAs. Heavier coarse aggregate of ilmenite dampens the effect of higher temperatures on GC strength compared with lighter aggregates. In addition, replacing crushed dolomite with heavyweight aggregates of EAFSS, barite and ilmenite increases the attenuation rate to 27%, 21% and 13%, respectively. This finding confirms that the type of aggregate used in the production of GC is important for reducing the permeability of X-ray.

Mitigation of environmental problems using brick kiln rice husk ash in geopolymer composites for sustainable development

Brick kilns uses assorted amount of rice husk as fuel to fire the stacks of soil bricks. In India, the rice husk ash (RHA) created during the burning process of bricks has yet to be properly exploited. The main focus of this study is to enhance the structural properties of geopolymer composites using brick kiln incinerated rice husk ash waste. The Physico-chemical analysis of brick kiln rice husk ash indicates the presence of high silica (88%) content with the evidence of XRD and FTIR analysis, SEM images shows high porous structure and PSD analysis gives a bonding nature of particle size as binding ingredient. The geopolymer mixes were made manually with different percentage of RHA 0%, 10%, 20% and 30% replaced partially in Siliceous Flyash. To identify suitability of the mixture for geopolymer concrete production, properties like workability and fresh density of the mixture was investigated using manually casted cubes having a size of 100 ​mm and keeping for oven drying at 40° ±2 ​°C upto 24 ​h. Compressive strength as destructive structural test method was investigated at the respective duration of curing. The findings led to the conclusion that increasing the percentages of RHA in the combination improves the mixture for geopolymer concrete composites with the increase of curing time. At 10% RHA addition, the optimal compressive strength of 42.19 ​N/mm2 was achieved. The compressive strength of the RHA was found to decrease by 0.8% at 10% addition, which is negligible when compared to the control geopolymer mix (i.e., mix with 0% RHA), implying that the RHA from brick kilns can be employed to improve the structural qualities of geopolymer concrete composites.

Compressive strength of geopolymer concrete with fly-ash from Paiton Steam Power Plant and variations of substitution sodium silicate (Na2SiO3) with natural zeolite

Geopolymer concrete is one of the technological innovations of concrete without cement. It was prepared using fine aggregates, coarse aggregates, fly-ash, sodium hydroxide (NaOH), and sodium silicate (Na2SiO3). In the production of geopolymer concrete, sodium silicate and sodium hydroxide serve as an alkaline activator. One of the natural materials that can be used as an alternative material is natural zeolite. Zeolit contains high silica and alumina, that expected to increase the compressive strength of geopolymer concrete. This research aims to develop geopolymer concrete technology by understanding the setting time behaviour and compressive strength by substitution sodium silicate (Na2SiO3) with natural zeolite. The percentage of zeolite that substitute for sodium silicate is 0%, 2.5%, 5%, and 7.5 %. The molarity of NaOH is 12 M. Meanwhile, the ratio of sodium hydroxide and sodium silicate is 1:2.5. Compressive strength testing is carried out on cylindrical specimens 10 cm × 20 cm. The results show that natural zeolite can accelerate the setting time of geopolymer paste. The fastest initial setting time is 48 minutes. Meanwhile, the final setting time is 60 minutes in geopolymer paste with substitution sodium silicate using 7.5 % zeolite. In addition, for compressive strength results, zeolite can increase compressive strength. The highest average of compressive strength results is 46.07 Mpa in substitution of Na2SiO3 with 7.5 % zeolite.

Effect of Partial Replacement of Ground Granulated Blast Furnace Slag with Sugarcane Bagasse Ash as Source Material in the Production of Geopolymer Concrete

The study on the characteristics of geopolymer concrete (GPC) is of ultimate significance to instill assurance in builders and engineers. Abundant available literatures point towards the utilization of fly ash and ground granulated blast furnace slag (GGBFS) as source material in the production of GPC with little on other materials. India produces nearly 350 MMT of sugarcane for the production of sugar, which lies second only to Brazil in the annual production, the disposal of the bagasse creates an environmental issue needs to be effectively utilized. Hence, this work was intended to investigate the effect of utilizing sugarcane bagasse ash (SCBA) as a source material in the production of geopolymer mixes. The fresh (consistency, setting time, soundness and flow), hardened (density, compressive strength, expansion and pH) and microstructural properties (X-ray diffraction) of the tested mixes were asessed. The results infer that 20 % replacement level of GGBFS with SCBA produces superior compressive strength and all other results were within the permissible limits even at 40 % replacement level.