Geopolymer Concrete Specimens Research Articles

Studies on the Permeation Properties of Geopolymer Concrete made with Sugarcane Bagasse Fiber

Different fibers like steel, glass, basalt, coconut, sugarcane fibers are used to improve the tensile strength in the concrete. The sugarcane bagasse fiber (SCBF) is utilized in this paper work. This SCBF is the final extract of the sugar industries which contains the large fibers. The main objective of this paper is to study the effect of SCBF on the permeation properties of the geopolymer concrete (GPC) of G40 and compared to its equivalent M40 grade. The specimens of conventional concrete (CC) and conventional concrete with SBF (CCF) are casted and cured in the curing tanks for a period of 28 day, and the GPC and GPCF specimens are casted and oven cured at a temperature of 60OC for a time period of 24 hours and the test are performed after 28 days of ambient curing of the specimens. The permeation test like (Water absorption test, Sorptivity and Water Permeability test) are carried in the paper. Based on the results it is observed that the permeation properties of CCF and GPCF are more resistant when compared to the CC and GPC respectively.

Flexural strength of Lightweight geopolymer concrete using sisal fibres

Lightweight concrete is usually chosen for structural purpose where its use will lead to a lower overall cost of a structure than normal weight concrete by reducing its dead weight. This weight will make it an uneconomical structural material. Attempts have been made in the past to reduce the self-weight of concrete to increase the efficiency of concrete as a structural material. In this research, bamboo sticks are used in the form of coarse aggregate at different proportions to reduce the self-weight of concrete. Also, naturally available fibre named sisal fibre is into the reinforcement to study its properties. The influence of sisal fibres and bamboo sticks on the strength of light weight geopolymer concrete is taken as the main objective of this experimental study. In recent years, a great deal of interest has been created worldwide on the potential applications of light weight concrete and utilization of natural fibres reinforced cement-based composites. In this work, it is also aimed to investigate the strength properties of concrete by casting light weight geopolymer concrete by replacing bamboo aggregates with 10%, 20% and 30% of coarse aggregate. Also, Sisal fibres are added at different proportions as 0.25%, 0.5%, 0.75% and 1.0% by volume of concrete respectively. Evaluation of flexural bending strength for M25 geopolymer concrete specimens was done. Totally 9 number of 500×100×100 mm flexural members are cast and tested under M25 grade of concrete. The 12 M NaOH, ratio of NaOH:Na2SiO3 as 2.5 and ratio of flyash to alkaline activator solution as 0.6 are considered as various parameters for designing the mix of geopolymer concrete. Ambient curing condition is applied for evaluating strength properties. The flexure strength was tested with replacement of coarse aggregate with bamboo sticks and by adding different percentage of sisal fibres. The test results indicated that the sisal fibres were effective in improving the strength of concrete.

Testing and modelling of geopolymer concrete members with fibreglass reinforcement

The poor durability of ordinary Portland cement concrete and the corrosion of conventional steel reinforcement have a major impact on the viability, safety and serviceability of reinforced concrete structures, particularly in marine environments. Geopolymer concrete (GPC) reinforced with corrosion-free glass-fibre-reinforced polymer bars is ideal for projects such as bridge piers in coastal zones where corrosion is severe. This paper reports on an examination into the behaviour of this novel construction material under axial, combined and flexural loading and validation of a numerical model of the material. To this end, 11 GPC specimens constructed with various stirrup spacings were subjected to a range of loading conditions. The concrete was modelled using the widely used concrete damage plasticity model and linear elastic behaviour was used for the fibreglass bars and stirrups. The predicted axial load–deflection responses were in close agreement with the experimental data, especially for concentrically loaded columns. The load capacities of eccentrically loaded columns and beams were slightly overpredicted by the model due to a tendency of the fibreglass stirrups to open up prematurely.

Characteristics of Blended Geopolymer Concrete Using Ultrafine Ground Granulated Blast Furnace Slag and Copper Slag

This paper presents the properties of blended geopolymer concrete manufactured using fly ash and ultrafine Ground Granulated Blast Furnace Slag (UFGGBFS), along with the copper slag (CPS) as replacement of fine aggregate (crushed stone sand). Various parameters considered in this study include different sodium hydroxide concentrations (10M, 12M and 14M); 0.35 as alkaline liquid to binder ratio; 2.5 as sodium silicate to sodium hydroxide ratio and cured in ambient curing condition. Further, geopolymer concrete was manufactured using fly ash as the prime source material which is replaced with UFGGBFS (0%, 5%, 10% and 15%). Copper slag has been used as replacement of fine aggregate in this study. Properties of the fresh manufactured geopolymer concrete were studied by slump test. Compressive strength of the manufactured geopolymer concrete was tested and recorded after curing for 3, 7 and 28 days. Microstructure Characterization of Geopolymer concrete specimens was done by Scanning Electron Microscope (SEM) analysis. Experimental results revealed that the addition of UFGGBFS resulted in an increased strength performance of geopolymer concrete. Also, this study demonstrated that the strength of geopolymer concrete increased with an increase in sodium hydroxide concentration. SEM results revealed that the addition of UFGGBFS resulted in a dense structure.

Utilization of PET bottles and plastic granules in geopolymer concrete

Abstract This research work investigates the utilization of plastic wastes in the form of Polyethylene terephthalate (PET) bottles. PET bottles are used as a whole bottles inside geopolymer concrete specimen in proportions such as 3, 6 and 12. PET bottles are shredded and crushed to fine powder and are used as a partial replacement of M-sand in proportions such as 5, 10 and 15 percent. The novelty of this work lies in the utilization of PET bottles in geopolymer concrete. In this research, works have been focused to develop pervious geopolymer concrete using Ground Granulated Blast Furnace Slag as the base material. Combination of sodium hydroxide and sodium silicate solution was used as the alkaline activator solution. Properties such as workability, compressive strength, tensile strength and water absorption are determined in this work. Also effort has been made to analyze the behavior of specimen embedded with plastic at elevated temperatures such as 200, 400, 600 and 800 °C. This research unleashes the scope of utilization of waste plastics inside sustainable geopolymer concrete.

Study of strength characteristics of Geo-Polymer Concrete by using Rice husk Ash, Steel fiber and Quarry Dust

Environment pollution is one of the major problems faced by world today. In the field of construction industry mainly, the manufacturing of Portland cement will matter the emission of pollutants results in environmental pollution. To reduce the pollution effect on environment we can use industrial by-products in our construction industry. To produce the geo-polymer concrete the Portland cement is fully replaced with Rice husk ash and the fine aggregate is replaced with quarry dust for the binding of material alkaline liquids are used in this study. Rice husk ash is a by-product from the burning of rice husk at a temperature lower than 6000C.this means that it is in a form that is soft and easy to grind. Rice husk ash is rich in silica about 90%, 5% carbon and 2% K2O. The specific surface of RHA is between 40-100m2/g. The alkaline liquids used in this study Sodium hydroxide (NaOH) and sodium silicate (Na2Sio3). Different molarities of sodium hydroxide solution i.e. 8M and 10M are taken to prepare different mixes. The cube specimens are taken of size 150mm x 150mm x 150mm and the compressive strength is calculated for each of the mix. The geo-polymer concrete specimens are tested for their compressive strength at the age of 7days, mixes of varying sodium hydroxide molarities i.e. 8M and 10M are prepared and they are cured by direct sun-light and strengths are calculated for 7 day. The finding shows that the strength of Geopolymer concrete is increasing with the increase of the molarity of sodium hydroxide.

Deterioration of ambient-cured and heat-cured fly ash geopolymer concrete by high temperature exposure and prediction of its residual compressive strength

This paper presents an investigation on the performance of ambient-cured and heat-cured low-calcium fly ash geopolymer concrete after exposure to elevated temperatures. The concrete specimens were heated to 100, 200, 400, 600, 800 and 1000 °C at a heating rate of 5 °C/min. The effect of high temperature exposure on geopolymer concrete was studied by visual inspection, mass loss, extent of cracking, residual strength and microstructure investigation. The total length of cross-section cracks and surface cracks reached their peak values at 800 °C and then declined at 1000 °C. The results show that all the concrete specimens could be heated at 600 °C for 2 h without strength loss. Heat-cured geopolymer concrete specimens showed higher residual compressive strengths than the ambient-cured specimens for all the exposure temperatures. A crushing index of 7.7% could be regarded as the threshold value for coarse aggregate to maintain the initial compressive strength of concrete up to 600 °C. Thus, the microstructural damage as observed by SEM images, dehydration of geopolymer shown by thermogravimetric analysis and the reduced strength of coarse aggregate are considered as the contributing factors for strength losses at temperatures higher than 600 °C. Finally, two prediction equations are proposed which correlated well with the experimental results of this study and those reported in published literature.

Strength Enhancement on Mechanical Properties of Geopolymer Concrete with Magnetized Water and Recycled Coarse Aggregate

Cement is probably the mostly widely used construction material in the world. However, the production of cement releases CO2 into the air. Greenhouse effect is mainly caused by carbon- di-oxide. Hence, there is a need to develop sustainable alternatives to Portland cement. One of the suitable alternatives is usage of Geo-Polymer Concrete (GPC) which is made from utilization of waste materials like fly ash and ground granulated blast furnace slag (GGBS) with suitable alkali activators. In general, chemical admixtures are added to get concrete with increased strength. The chemical admixtures for increasing the strength are not easily accessible in rural areas. The fresh and hardened properties of concrete are improved by using magnetic water. The scaling and corrosion are greatly reduced using magnetic water. It is due to the change in microstructure of water molecules making it soft water. Further, recycled coarse aggregate was used with coarse aggregate in the study. The specimens were cast and were investigated for Compressive strength, Split Tensile strength and Flexural strength test after 7 days and 28 days of ambient curing. It was observed that Compressive, Split Tensile and Flexural strength of the GPC specimen with magnetic water increased compared to other mix proportions.

Structural performance of hybrid fiber geopolymer concrete beams

This research work aims at investigating the structural properties of hybrid fiber reinforced geopolymer concrete specimens such as load-deflection behaviour, stiffness, ductility, toughness index. In this research work, effort has been made towards reducing the brittleness of geopolymer concrete by the addition of glass (high modulus) and polypropylene (low modulus) fibers inside GGBS based geopolymer concrete made of M-sand. The glass and polypropylene fibers were added in various proportions such as 1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75,0/1. The research work recorded enhancement of structural properties of geopolymer concrete under ambient curing. This work paved way for the utilization of fibers inside geopolymer concrete and replace cement concrete in all facets.

Comparative Study Involving Effect of Curing Regime on Elastic Modulus of Geopolymer Concrete

Geopolymer Concrete (GPC) as a cement-less construction material has attracted worldwide attention due to its lower carbon footprint. There are numerous studies reported on GPC made using different by-products including fly-ash. However, since the use of bottom-ash is comparatively limited, making potassium-based GPC using this waste can be an alternative to Portland Cement Concrete (PCC). In this study, two methods of accelerated curing were used to determine the influence of elevated temperature on the compressive strength of GPC, composed of 50% bottom-ash and 50% fly-ash. GPC specimens were cured using various temperatures including ambient, 30 °C, 45 °C, 60 °C, and 80 °C for 24 h, all followed by 28 days of ambient curing. The highest compressive strength was obtained with steam curing at a temperature of 80 °C for a duration of 24 h. It is of great significance to evaluate elastic modulus of the concrete mixture so that the short-term rigidity of structures subjected to elongation, bending, or compression can be predicted. In this study, a longitudinal Resonant Frequency Test (RFT) as a non-destructive test (NDT) was used to calculate the elastic modulus of both GPC and a comparative PCC mix. Based on the results, PCC had higher resonant frequency (by about 1000 Hz) compared to GPC. A review of empirical models for predicting GPC’s elastic modulus showed that all of the predicted elastic modulus values were lower than experimental values.

Influence of nano TiO2 on strength and durability properties of geopolymer concrete

Geopolymer concrete (GPC) is treated as an ecologically pure construction material because cement is completely retrieved by pozzolanic materials that are abundant in alumina and silica. GPC is actuated with alkaline liquids to begin as a binder in concrete. Geopolymer concrete evince many outstanding properties just as rapid strength, less shrinkage, and less creep, better resistance against sulphate and chloride attacks. The current review is to explore the effect of nano titanium dioxide (nano-TiO 2 ) on fly ash based geopolymer concrete (FAGPC) with oven curing at 60 0 c for 48 hrs. As an initial study, GPC with 10 M was carried out for dissimilar ratios of sodium silicate (Na 2 SiO 3 ) to sodium hydroxide (NaOH) solutions between 1.5 and 3.5. Out of all mixes, alkaline activator ratio harmonize to the highest compressive strength was ascertained at 2.5. This ratio was kept constant for further study in GPC carried out by replacing fly ash with nano TiO 2 between 1% and 5%. For all mixes of GPC with and without nano titanium dioxide, mechanical and durability properties were observed and evaluated. The test results depict that, percentage increase of nano TiO 2 , gives rise to decline in workability and improves strength properties of concrete. The maximum strength enrichment was noticed when 5% of nano-TiO 2 was incorporated in GPC. As percentage of nano TiO 2 hiked in GPC, the results of RCPT, Water absorption and Sorptivity decreased. All these GPC specimens are immersed individually in 5% magnesium sulphate and 5% sodium chloride to know the resistance of geopolymer concrete against sulphate and chloride attacks. Results of this study concluded that increase in nano TiO 2 percentage gives better performance against sulphate and chloride solutions. Change in microstructure and mineral phases of reference geopolymer concrete samples and maximum strength obtained geopolymer concrete samples containing nano TiO 2 was investigated using SEM and XRD analyses.

Influence of activator solution on microstructural and mechanical properties of geopolymer concrete

Geopolymer Concrete (GC) is an innovative and Eco-friendly construction material and an alternative to Portland cement concrete. The binders such as fly ash, Ground Granulated Blast Furnace Slag (GGBS), and cement used to produce GC in this research work. These binders activated through two types of solutions (an alkaline solution which prepared in the laboratory and activator solution purchased commercially). An attempt has made to observe the advantages of commercially available activator solutions on properties of GC. The test results of laboratory prepared alkaline solution based GC specimens compared with commercially available activator solution based GC. The mechanical properties were investigated with 20% and 30% addition of GGBS and cement to fly ash based GC samples. Besides, the analysis of the specimen through SEM and EDS indicated that the components having a considerable influence on the structure of the GC were the Al and Si components. The XRD results revealed that there were no practical differences in the intensity according to the differences in the chemical elements of the alkaline/activator solutions. However, the TG/DT analysis made it possible to identify changes in mass loss of different proportions based GC. The alkaline solution based mixes attained enhanced mechanical properties compared to activator solution based GC samples. The microstructural studies revealed the reasons behind the strength improvement of fly ash-GGBS based GC.

Behaviour of GGBS-dolomite geopolymer concrete short column under axial loading

Geopolymer concrete was developed from Ground Granulated Blast furnace Slag (GGBS) and dolomite which are obtained from steel and rock industries. Optimum proportions of GGBS and dolomite were found out based on the maximum compressive strength. GGBS-Dolomite geopolymer concrete can reduce construction time and cost due to high early age strength. Experimental investigations were conducted to evaluate the behavior of GGBS-dolomite geopolymer concrete short columns under axial loading. GGBS-dolomite geopolymer concrete column showed better stress-strain behavior compared to cement concrete specimens. Load carrying capacity of geopolymer concrete specimens were improved by adding steel fibres at 0.25, 0.5 and 0.75% by volume of concrete. Ductility of geopolymer concrete was enhanced by 18%, 30% and 45% with the addition of steel fibres in the range of 0.25-0.75% by the volume of concrete. Parameters such as ultimate load, deflection, ductility and crack pattern of axially loaded short columns were evaluated using finite element method. It was observed that geopolymer concrete has 28% reduction in cost/ultimate load compared to ordinary concrete. GGBS-dolomite geopolymer concrete short columns without ductile detailing behaves similar to that of cement with ductile detailing (as per IS 13920-2016) with reduced cost/strength ratio.

ENGINEERING PROPERTIES OF LIGHTWEIGHT GEOPOLYMER CONCRETE USING PALM OIL CLINKER AGGREGATE

The palm oil industry generates a significant amount of wastes which their managing has been a major environmental concern in producing countries. The utilization of these wastes as an aggregate source for concrete production will help to sanitize the environment and provides a cheaper and renewable aggregates source for construction industries. This paper presents the results of the experimental program conducted on fly-ash based geopolymer concrete containing Palm Oil Clinker Aggregate (POCA). Several geopolymer concrete mixes were prepared in which POC was used as a replacement to both fine and coarse aggregates at different percentages starting from 25% to 100%. Mix proportioning was done in accordance with ACI 211.1-91. Geopolymer concrete specimens were cast, cured at ambient conditions and tested for the slump, density, water absorption and compressive, shear and flexural strengths. Overall, the use of fly ashbased geopolymer binder and POCA can enhance the sustainability aspects in concrete production as well as produce a high strength concrete. A concrete mixture containing 100% POCA can produce a structural lightweight concrete having a compressive strength of more than 30 MPa and a density of 1821 kg/m3. The use of a geopolymer binder promotes the workability and strength of POCA concrete and reduces its water absorbability. Incorporation of POCA up to 75% did not much change the structural efficiency of the produced concrete, while it was reduced by 32% when the POCA fully replaced the natural aggregate. Nevertheless, the benefits in terms of cost, energy, and environmental savings cannot be overlooked.

Developing Geopolymer Concrete Properties by Using Nanomaterials and Steel Fibers

This research investigates the simultaneous impact of two different types of steel fibers, nanometakaolin, and nanosilica on the mechanical properties of geopolymer concrete (GPC) mixes. To achieve this aim, different geopolymer concrete mixes were prepared. Firstly, with and without nanomaterials (nanosilica and nanometakaolin) of 0, 2%, 4%, 6%, and 8% from ground granulated blast furnace slag (GGBFS) were used. Secondly, steel fiber (hooked end and crimped) content of (0, 0.5%, 1, and 1.5%) was used. Thirdly, optimum values of nanomaterials with the optimum values of steel fiber were used. Crimped and hooked‐end steel fibers were utilized with an aspect ratio of 60 and a length of 30 mm. Geopolymer mixes were manufactured by using a constant percentage of alkaline activator to binder proportion equal to 0.45 with GGBFS cured at ambient conditions. For alkaline activator, sodium hydroxide molar (NaOH) and sodium hydroxide solution (NaOH) were used according to a proportion (Na2SiO3/NaOH) of 2.33. The hardened concrete tests were performed through the usage of splitting tensile strength, flexural, and compressive experiments to determine the impact of steel fibers, nanometakaolin, and nanosilica individually and combined on performance of GPC specimens. The results illustrated that using a mix composed of the optimum steel fibers (1% content) accompanied by an optimum percentage of 6% nanometakaolin or 4% nanosilica demonstrated a significant enhancement in the mechanical properties of GPC specimens compared to all other mixtures. Besides, the impact of using nanomaterials individually was found to be predominant on compressive strength on GPC specimens especially with the usage of the optimum values. However, using nanomaterials individually compared to using the steel fibers individually was found to have approximately the same splitting tensile strength and flexural performance.

Performance evaluation of fly ash/slag based geopolymer concrete beams with addition of lime

This paper evaluates the structural properties of geopolymer concrete beams with the addition of hydrated lime. The fly ash and GGBS are added in powder form with the ratio of 60% and 40%. A total number of six beam specimens are tested under two point static loading condition. The beams are cured under room temperature in ambient condition. Out of six beams three beams are geopolymer concrete beams with molarity concentration of 8 M, 10 M and 12 M respectively and another three beams the hydrated lime is replaced by 5% by weight of alumino silicate materials. The load deflection behaviour and flexural parameters like stiffness, ductility and energy absorption capacity are studied and compared with conventional geopolymer concrete specimen.

Durability properties of geopolymer concrete made from fly ash in presence of Kaolin

Effect of Kaolin on the durability of Fly ash based geopolymer concrete has been studied. Four different geopolymer concrete specimens designated as MX1, MX2, M3 and MX4 were made. The specimens were cured in oven at 100 °C for 3 days and left for another 28 days at room temperature before exposing them to chemical environment. The specimens were subjected to 2% sulphuric acid and 5% sodium sulphate to investigate their durability properties. Resistance to chemical attack was evaluated as per changes in weight and loss in compressive strength at different intervals of time. Grade 40 Ordinary Portland Cement (OPC) concrete was cast and subjected to the same condition to serve as a control. The results showed that the resistance of geopolymer concrete incorporating Kaolin was significantly higher than that of control and also higher than geopolymer concrete with 100% fly ash. The overall performance showed that the resistance of all the geopolymer concrete mixtures to chemical attack were higher than that of OPC concrete.

Effects of ultra fine slag as mineral admixture on the compressive strength, water absorption and permeability of rice husk ash based geopolymer concrete

Geopolymer concrete (GPC) is a sustainable green concrete, replaces ordinary Portland cement concrete prepared by activating aluminosilicate based industrial waste materials with an alkaline solution as an alkaline activator. In this paper rice husk ash (RHA) based GPC was prepared with varying the percentages of ultra-fine slag (UFS) and RHA, activated with an alkaline mixture of sodium hydroxide and sodium silicate with desired proportion. The ambient curing method was used at an average temperature of 27-degree Celsius. The compressive strength, the durability property of GPC in terms of water permeability and water absorption were investigated. Effects of several parameters such as the percentage of ultrafine slag, duration of curing, RHA content on water permeability, and water absorption of geopolymer concrete was studied. The result shows that the inclusion of ultra-fine slag significantly improvises the durability properties of RHA based geopolymer concrete. GPC specimens prepared with ultra-fine slag appear to have improved densification. The analysis of results shows that with a higher percentage of ultra-fine slag in rice husk ash geopolymer concrete has a substantial effect in enhancing the strength properties.

Effect of Ground Granulated Blast Furnace Slag as Partial Replacement in Fly Ash-Based Geopolymer Concrete

Replacement of Ordinary Portland cement (OPC) with geopolymer concrete (GPC) using fly ash is currently utilized in the construction industry to reduce the excessive carbon footprint. However, fly ash has lower strength development compared to OPC. Due to that reason, ground granulated blast furnace slag (GGBFS) is chosen to be blended with fly ash to produce GPC with improved mechanical strength. The analysis of the mechanical properties includes workability, compressive strength and splitting tensile strength of hardened GPC specimens have been carried out. The specimens were prepared with different percentages of GGBFS, from 0 % up to 20 %, partially replacing the fly ash-based GPC. Experimental results showed that the slump, compressive strength and splitting tensile strength of the GPC increase as the GGBFS percentage increases and found to be suitable for structural application.

Effect of GGBS and chloride on compressive strength and corrosion performance of steel in fly ash-GGBS based geopolymer concrete

This study investigates the effect of GGBS on strength and corrosion performance of steel in chloride contaminated fly ash-GGBS based geopolymer concrete (GPC). Fly ash and fly ash-GGBS based GPC mixes were added with 0% and 3.5% of NaCl during the time of preparation. Corrosion potential measurement and corrosion current density by linear polarization resistance (LPR) measurement were performed on reinforced cylindrical GPC specimens. Results indicated that the fly ash-GGBS based GPC showed higher compressive strength as compared to fly ash based GPC, due to formation of N-(C)-A-S-H and C-S-H gel in fly ash-GGBS based GPC which is evident from FESEM analysis. The chloride admixed GPC mixes achieved lower compressive strength than that of control (0% NaCl) GPC mixes. There was a higher probability of corrosion initiation and higher corrosion current density of steel reinforcement in NaCl added GPC as compared to the control GPC.