Geopolymer Research Articles

A study on evolution of geopolymer concrete

In current year the waste created from industry is the colossal worry for different climate, wellbeing, and used for land filling. Reusing of squanders and utilizing industrial waste in development elements has all the earmarks of being reasonable arrangement not exclusively to the contamination issue yet additionally a conservative choice in development. There are numerous decisions concerning choice of materials in developments. Because of developing interest in supportable development, specialists and planners are spurred to pick the elements are supplementary realistic. Geo polymer concrete competent economical development is portrayed by use of mechanical squanders to decrease utilization of common assets and energy and contamination of the climate. Substitution of materials over ostensible cement is the thing that makes more environmental friendly concrete as Geo polymer concrete. It restrains fly ash, alkaline solution arrangement as restricting element. Considering usage of mechanical desecrates in Geo polymer Concrete, the current journal surveys different Industrial desecrate materials at various steps in Geo polymer Concrete. Compressive strength of Geo polymer Concrete fusing distinctive desecrate resources is looked into and proposals are recommended at the result of the investigation. The evaluated move toward for improvement of innovative development fabric utilizing mechanical desecrate is valuable to give a likely economical resource. The principle intention of this examination expand the potency of Geo polymer cement and Geo polymer concrete by supplanting characteristic assets with different modern waste materials such as fly ash, GGBS, Copper Slag, M−Sand, Silica Flume etc., reintegrated by natural revenue in Geo polymer concrete. Cost of geopolymer concrete is low similar higher grade strength cement concrete cost. This paper gives an audit of examination period in the region of Geo polymer concrete.

Experimental research of hybrid fibers based Geo-polymer concrete

In development enterprises, concrete is regularly utilized material. For the creation of concrete, development industry utilizes a large portion of the regular assets. During the creation of concrete, carbon dioxide is delivered which may prompts ozone harming substance emanation impact. For this geopolymer concrete has been found for the substitute to the OPC. It utilizes mechanical waste material, for example, fly debris, GGBS, rather than concrete, there by diminishing effects because of concrete. Ground Granulated Blast furnace Slag (GGBS) is a by-product from steel industry. It has good structural and durable properties with less environmental effects. This paper critically reviews the literatures available on GGBS used in cement concrete. The utilization of supplementary cementitious materials is well accepted because of the several improvements possible in the concrete composites and due to the overall economy. The present paper is an effort to quantify the 28-day cementitious efficiency of ground granulated blast furnace slag (GGBS) in concrete at the various replacement levels. It was observed that this overall strength efficiency of GGBS concretes can also be defined through a procedure adopted earlier for other cementitious materials like fly ash and silica fume. Fly debris and GGBS are the covers which respond with basic arrangement like Na2SiO3 and NaOH and structure a gel which effectively ties with fine total and coarse total. Strands are added to the geo polymer concrete in the scope of 0.1%, 0.2%, 0.3%, 0.4% and 0.5% at 0.1% increases. In this examination, different rates of basalt strands, AR glass filaments and polypropylene filaments are added to the geo polymer concrete and the compressive, flexural and split elasticity of various blends were contrasted and geo polymer concrete, to know the quality of shapes, chambers and pillars. In this task, indicated that the more retarder added, the setting season of geo polymer solid will be expanded, subsequently expanding its functionality.

Strength analysis of geo-polymer concrete based on GGBS/rise husk and p-sand

The world is facing now a day a serious causes environmental pollution, because world uses the concrete next to the water and the production of cement is highly extensive. At the time of production of cement and drastic amount of carbon dioxide is emitted which causes huge global warming. So, to reduce the environmental pollution there should be any other replacement material for cement in order to reduce the emission produced in the construction industry. And in this context the use of Geo polymer concrete in which no cement is been used. To produce the Geo polymer, concrete the Portland cement is fully replaced with GGBS (or) Rise husk ash and the fine aggregate is replaced with P-Sand and alkaline Liquid can be used in this process of binding of materials. This alkaline liquid used are Sodium Hydroxide (NAOH) and sodium Silicate (NO2O3) for the Polymerization. Various molarities of Sodium hydroxide (NaoH) solution. i.e., 8 M, 10 M and 12 M for the preparation of different blends. The cube specimen of size 150 mm ×150 mm ×150 mm and 1 m3 cube are taken. And the compressive strength is being calculated for each mix. The compressive strength is tested at the age of 21 days. Then the Sodium hydroxide molarities are cured by direct sunlight and the strength are being calculated for 21 days. This paper includes various laboratory tests conducted on strength of Geo polymer concrete include with the increase of Sodium hydroxide and the aggregate GGBS or Rise husk mix.

Investigation on alkali activated fly ash and slag concrete using neutral grade water glass as activator

The utilization of cement in concrete was an ancient method as well the utilization of cementitious materials in concrete not only improves mechanical properties but also improves workability and durability etc., Today urbanization expands in many folds, so that the usage of cement became more due to this the production of cement increases. The production of cement on one hand affects the environment in form of Carbon dioxide gases on other hand depreciation of raw materials like lime stone and sand etc. Globally many construction industry and researches focussed in reduction of cement content in concrete by production of new alternatives like Geo polymer concrete etc. In this investigation Alkali-Activated Fly Ash slag concrete (AAFSC) is introduced as an alternative for ordinary Portland cement concrete (OPCC). Researchers developed AAFSC with NaOH and Na2SiO3 as activators. In this study AAFSC produced is with neutral grade sodium silicate solution with silica modulus 2.9 (Ms).For production of AAFSC the quantity of binder content is 500kg/m3 by varying binders proportions like Fly Ash and GGBS along with solution/binder ratios varying from 0.6 to 0.7. During this experimental investigation the workability and compressive strength of AAFSC is tested.

Mathematical model for predicting stress-strain behavior of low calcium fly-ash based geopolymer concrete

The focus of the study was to identify the stress strain behavior of geo polymer concrete and salient parameters that influence the mixture proportions and the properties of low calcium fly ash- based geo polymers concrete. To develop geopolymer concrete the chemical proportions are alkaline liquid solution/fly-ash ratio=0.5, Sodium silicate/sodium hydroxide ratio=2.5,16M NaOH and SiO2/Na2O ratio=2.0. The geopolymer concrete mixes have shown improved stress values for the same strain levels compared to that of controlled concrete mix. Normalized stress strain curves are used to compare the behaviours of geopolymer concrete. It can be observed that geopolymer concrete has improved strains for the same stress when compared to conventional concrete. Geopolymer concrete mixes have shown improved stress values for the same strain levels compared to that of controlled concrete mixes.

Proposed mathematical model for stress- strain behaviour of geopolymer concrete

In the present study, appropriate analytic stress-strain mathematical model is developed that can capture the real (observable) stress-strain behaviour of geo polymer concrete. The geo polymer concrete mixes have shown improved stress values for the same strain levels compared to that of controlled concrete mix in M20 grade. The analytical equations for the stress-strain response of conventional and geopolymer concrete mixes have been proposed in the form of y = Ax / (1+Bx+Cx2), both for ascending and descending portions of the curves with different set of values for constants. The proposed equations have shown good correlation with experimental values. The proposed empirical equations can be used as stress block in analyzing the flexural behavior of sections of controlled and geo polymer concrete. The stress-strain curves obtained in the experiment for M20 & G20 grades of controlled and geo polymer concrete exhibit a similar trend when compared to the empirical equations of modified Saenz model. So Saenz mathematical model is successfully evaluated and validated for geopolymer concrete.

An Experimental Study on Short Term Durability and Hardened Properties of Baggasse Ash and Fly Ash Based Geo Polymer Concrete

This project reports the comparison of bagasse ash and fly ash-bagasse ash based on geopolymer concrete. In which cement is fully replaced by pozzolanic material that is rich in silicon and aluminium like fly ash and bagasse ash referred to as “Geopolymer concrete” which is a contemporary material. Geopolymer concrete was actually manufactured by reusing and recycling of industrial solid wastes and by products. Fly Ash, a by-product of coal obtained from the thermal power plant is plenty available worldwide. Fly ash is used as ingredients in concrete which enhance the properties of concrete and utilization of fly ash is helpful for consumption. Bagasse ash is a final waste product of sugar obtained from the sugar mills. The base material, viz. fly ash and Bagasse ash, is activated by alkaline solution that is sodium hydroxide and sodium silicate to produce a binder which is rich in silica and aluminium. Sample 1 is cement. It is replaced by 100% fly ash geopolymer concrete and trial 2 is 10%, 30% & 50% replaced by Bagasse ash in Geopolymer concrete . The project presents the strength and durability of Bagasse ash based Geopolymer concrete and fly ash and Bagasse ash based Geopolymer concrete.

Influence of nano material (TiO2) on self compacting Geo polymer concrete containing Flyash, GGBS and wollastonite

In the modern age, concrete has become major component in construction field which results in global warming as it contains high amounts of cement. To reduce the carbon footprint and help environment, In our research, cement is elemenated and this type of concrete is called “Geo-polymer concrete”. Binders like Fly-ash, Wollastonite and Ground Granulated Blast Furnace Slag (GGBS) are used and Alkali activators like sodium hydroxide and sodium silicate are used to improve the binding properties of the concrete. Titanium oxide is used to develop self-compacting Geo-polymer concrete (SCGPC). At ambient curing conditions, Fresh and hardened properties are tested at 7, 14 and 28 days. SCGPC mixes are developed by adding Titanium oxide to mixes with and without wollastonite at 2%, 4%, 6%. To obtain the optimum results we need to perform some Fresh and as well as the Hardened properties. The fresh properties tests include slump flow. Hardened properties of the concrete include the Compressive strength and Split Tensile. The optimum test results were obtained at 4% TiO2 with and without wollastonite. There is 18–20% increase in the strength by incorporation of wollastonite.

Development and testing of fast curing, mineral-impregnated carbon fiber (MCF) reinforcements based on metakaolin-made geopolymers

Mineral-impregnated, carbon fiber composites (MCF) are a promising alternative to conventional concrete reinforcements. For the efficient industrial production of MCF, sufficient processing time for the impregnation suspension must be ensured. In the present investigation, a metakaolin-made geopolymer (GP) has been developed and tested for this purpose. The impregnation of carbon-fiber yarns was performed continuously and automated. Subsequently, the MCF were heat-treated at 75 °C to accelerate the reaction processes. The mechanical performance of MCF gradually increased in the advancement of the curing process from 2 to 8 h, which is attributed to the greater extent of geopolymerization. In such extended curing, thermogravimetric and microscopic analysis showed indeed a more “reacted” microstructure but also a higher content of voids. After heating for 8 h, the tensile strength and Young's modulus of MCF reached 2960 MPa and 259 GPa, respectively, when related to the yarn cross-sectional area.

Green Synthesis of High-performance Graphene Geopolymer Composites: A Review on Environment-friendly Extraction of Nanomaterials

Green Synthesis of High-performance Graphene Geopolymer Composites: A Review on Environment-friendly Extraction of Nanomaterials

Study on Workability and Strength Parameters on Geo polymer Concrete by Using GGBFS and Fly ash

Study on Workability and Strength Parameters on Geo polymer Concrete by Using GGBFS and Fly ash

An art of Research on concrete-Ternary blended

In this research, we experiment a ternary blended concrete, which is a concrete with silica fumes, GGBS, and Fly ash. By using sika viscocrete we achieved self compacting also, so it is a ternary blended self compacting geo polymer concrete. Three mixes were chosen namely M1, M2 and M3. The alkaline activator with different molarities were tried to get the optimum strength. The strength factors such as compressive strength and split tensile strength were carried out; similarly the fresh concrete properties such as slump test, flow table test, V-funnel test, U-Box Test & L Box test were carried out. The strength properties are did 7 days and 28 days. This research is mainly focused on fresh concrete properties of ternary blended self compacting geo polymer concrete.

Performance of Fly Ash and Ggbs Based Geopolymer Concrete Using Single Alkaline Activator Solution and Its Cost Analysis

Concrete is the most durable, versatile and reliable building material in the world. Next to water, concrete is the most used material. Ordinary Portland cement production accounts for 5-7% of total greenhous e gas emissions. It also consumes a lot of energy. Today, Geo-polymer concrete (GPC) has become a more sustainable concrete compared to conventional concrete. This research work focuses on the performance of Fly Ash and GGBS based geo-polymer concrete cured in outdoor conditions using a single alkaline activator solution (Geo activator). The variations of Fly Ash and GGBS were (FA100-GGBS0; FA90- GGBS10; FA70-GGBS30; FA50-GGBS50). In this study, only the Geo activator is used to activate Fly Ash and GGBS in the mixtures. Geo polymer concrete of size 100 mm x 100 mm x 100 mm was used in this research work to measure compressive strength at different ages of 7 days and 28 days. The results reveal that the increase in the proportion of GGBS content in the mix increases compression strength of concrete. The cost analysis was also carried for geopolymer concrete, compared with conventional concrete and the results reveals that for the lower grades, the cost will be the same as for conventional concrete and for the higher grades, the use of geo polymer concrete can reduce the cost of construction up to some extent.

The role of temperature and activator solution molarity on the viscosity and hard structure formation of geopolymer pastes

This study aimed to determine the impact of preparation temperature (10 °C to 20 °C) and different alkaline activator solution (AAS) molarities on the rheological behaviour, structure development, mechanical performance during geopolymer (GP) synthesis, and ageing of metakaolin (MK) based GP pastes. By decreasing the AAS molarity from 8 M to 5 M, the viscosity of AAS decreased by up to 1.68 times and GP pastes viscosity by up to 1.74 times. A temperature increase from 10 °C to 20 °C decreased the viscosity of AAS by up to 1.89 times and the viscosity of GP pastes by up to 1.29 times. With the AAS molarity decrease, an increase of GP paste spread diameter of up to 1.7 times was observed. At 10 °C, the spread diameter increased up to 51% and at 20 °C temperature, up to 57%. Decreasing the AAS molarity, MK/AAS ratio and preparation temperature of the samples led to a retardation in the structure formation in the GP samples during GP synthesis from 4 to 8 h. For samples prepared at 10 °C the UPV values were up to 12% lower than in the same composition samples prepared at 20 °C. Decreasing the AAS molarity and MK/AAS ratio in the samples led to a decrease in compressive strength after GP synthesis of up to 30%, however the UPV values and compressive strength in the samples prepared at 10 °C were up to 2.3% and 12.1% lower than in the samples prepared at 20 °C. The XRD results confirmed the compressive strength test results and revealed that a decrease of molarity and temperature led to a less intensive geopolimerisation reaction and hydroxide sodalite formation in the composition. After ageing, the UPV and compressive strength values in the samples mostly increased during the first 7 days, but after 56 days the UPV and compressive strength in the samples prepared at 10 °C and 20 °C practically levelled off.

Application of geopolymers synthesized from incinerated municipal solid waste ashes for the removal of cationic dye from water.

In this study, municipal solid waste bottom ash (MSW-BA) and fly ash (MSW-FA) were used as a source of aluminosilicate to prepare geopolymer (GEO) adsorbents (GEO-MSWBA and GEO-MSWFA) for the removal of methylene blue (MB) from water. The effects of temperature, pH, and initial concentration on the MB adsorption onto GEO-MSWBA and GEO-MSWFA were evaluated. The adsorption isotherms parameters and thermodynamics were also determined. Detailed physical and chemical characterizations of the prepared adsorbents were carried out to further understand their impact on MB adsorption. The results from the scanning electron microscopy revealed a uniform granule-sphere like structure on both prepared geopolymers, which would facilitate the MB adsorption onto the adsorbents. The X-ray diffraction allowed observation of the microstructural transformations that occur after the alkaline activation. The surface areas of the GEO-MSWBA and the GEO-MSWFA were recorded as 32.78 m2/g and 4.5 m2/g, respectively. From the Fourier transform infrared, a stretching vibration of the aluminosilicate tetrahedral was observed, which indicated the success of geopolymerization. The prepared geopolymers showed a high capability of MB adsorption from an aqueous solution. The adsorption process was best suited and explained using the Langmuir isotherm model with a maximum adsorption capacity of 666.7 mg/g for the GEO-MSWBA (at 25°C) and 769.2 mg/g for the GEO-MSWFA (at 35°C). The positive value of the enthalpy (ΔHo) for the GEO-MSWBA suggested the reaction favored endothermic reaction while the negative value of entropy (ΔSo) indicated a solid/liquid random interaction. On the other hand, the negative ΔHo value for the GEO-MSWFA indicated the reaction followed an exothermic reaction causing energy to be released, the positive ΔSo value indicated a good affinity at the solid-liquid surface. The overall negative value for Gibbs free energy (ΔGo) for both adsorbents suggested the adsorption was spontaneous and feasible. It was also inferred that n- π interaction, direct and indirect hydrogen bond, and electrostatic interaction between the MB and the prepared geopolymers facilitated the adsorption process. The current study shows that the GEO-MSWBA and the GEO-MSWFA have a great potential of removing MB as a cationic dye from water without performing any sort of laborious pretreatments.

Experimental studies on pervious geopolymer concrete

The aim of the investigation is to assess the features of the utilization of a geo polymer binder for producing permeable geopolymer concrete. Materials used for producing pervious geopolymer concrete are fly ash, ground granulated blast furnace slag with the proportion of 60:40, sodium silicate solution, sodium hydroxide and coarse aggregate. The strength, functional characteristics and its relationship of the geo polymer pervious concrete were investigated. Compressive strength of geo polymer permeable concrete has enhanced along with the rise in density of Pervious geo polymer concrete. Permeability and voids exhibit a decreasing pattern with the increase in molarity and alkali binder ratio. Based on the strength attainment in the previous geo polymer concrete, it has used as a sub - base and base course of a flexible pavement layers.

Enhancing Index and Strength Properties of Black Cotton Soil using Combination of Geopolymer and Flyash

A Combination of admixtures - fly ash and Geopolymer are used for stabilization of black cotton soil. Black cotton (BC) soils are mainly clayey soils having montmorillonite as their clay mineral. The moisture changes in BC soils will affect compressibility and strength characteristics, which are greatly enhanced with the addition of combination of Flyash (FA) and Geopolymer (GP). The evaluation study includes analysis of soil properties some of index properties like specific gravity, liquid limit, shrinkage limit and Uniaxial compression values. Different percentages of combination of admixtures (percentage by dry weight) are added to natural BC soil and further experiments are performed from these soil mix ratios (MR). The results show that the utilization of combination of admixtures decreases liquid limit by enormously and increases unconfined compressive strength i.e. the strength of the soil.

Performance studies on Geo polymer concrete

Geo polymer concrete, an eco-friendly concrete produced without addition of cement. Though cement is a basic material in the production of concrete; however in global carbon dioxide emission 5 to 8% contribution is from the production of concrete. In geo polymer concrete the absence of cement is replaced by an inorganic alumina silicate compound synthesized using fly ash as a binder. Fly ash involves in reduction of high energy consumption and offers solutions for utilizing waste by products from industries. This paper describes the experimental investigation on fly ash based Geo polymer concrete to evaluate the effects of workability, compressive and split tensile strength in order to ensure the overall performance of the concrete mix. The various parameters has been analysed based on the ratio of liquid to binder, molarity of sodium hydroxide solution, ratio of sodium silicate to sodium hydroxide and alkaline to fly ash ratio. The test results indicate that the compressive strength gradually increases with increase in molarity of NaOH solutions for two different alkaline to fly ash ratios of 0.35 and 0.5 respectively. The split tensile strength of geo polymer concrete is very low and not increases significantly. The workability of mix improves by adding 2% superplasticizer. Further overall performance is greatly influenced by the molarity of NaOH solution and the ratio of alkaline to fly ash to evaluate the early age strength of concrete.

Experimental investigation on characteristics of fly-ash based geo-polymer mixed concrete

Concrete is the mixture of sand, gravel, cement and water which is used in large scale to build structures in our earth and also the second-biggest producer of carbon dioxide emissions. This year alone, over 3.2 billion a lot of carbon dioxide are going to be discharged into our planet’s atmosphere. For over 2,000 years, we have been manufacturing cement by identical primitive technique of the heating and grinding of sedimentary rock. Humanity is currently on Fourth historic period, wherever technological advances are providing Architects, Engineers, and Material Scientists with the tools to supply the succeeding generation of superior, low-impact materials. Materials like geo-polymer concrete is a low-carbon, zero-waste, low cost model to safeguard our natural resources, cut back the carbon dioxide emissions and reduce global warming. In this paper, we've got done a close study on this geo polymer technology.

THz Fingerprints of Cement-Based Materials.

To find materials with an appropriate response to THz radiation is key for the incoming THz technology revolution. Unfortunately, this region of the electromagnetic spectra remains largely unexplored in most materials. The present work aims at unveiling the most significant THz fingerprints of cement-based materials. To this end transmission experiments have been carried out over Ordinary Portland Cement (OPC) and geopolymer (GEO) binder cement pastes in combination with atomistic simulations. These simulations have calculated for the first time, the dielectric response of C-S-H and N-A-S-H gels, the most important hydration products of OPC and GEO cement pastes respectively. Interestingly both the experiments and simulations reveal that both varieties of cement pastes exhibit three main characteristic peaks at frequencies around ~0.6 THz, ~1.05 THz and ~1.35 THz, whose origin is governed by the complex dynamic of their water content, and two extra signals at ~1.95 THz and ~2.75 THz which are likely related to modes involving floppy parts of the dried skeleton.