Effect of GGBFS on setting, workability and early strength properties of fly ash geopolymer concrete cured in ambient condition (original) (raw)
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Materials & Design, 2014
Inclusion of ground granulated blast-furnace slag (GGBFS) with class F fly-ash can have a significant effect on the setting and strength development of geopolymer binders when cured in ambient temperature. This paper evaluates the effect of different proportions of GGBFS and activator content on the workability and strength properties of fly ash based geopolymer concrete. In this study, GGBFS was added as 0%, 10% and 20% of the total binder with variable activator content (40% and 35%) and sodium silicate to sodium hydroxide ratio (1.5-2.5). Significant increase in strength and some decrease in the workability were observed in geopolymer concretes with higher GGBFS and lower sodium silicate to sodium hydroxide ratio in the mixtures. Similar to OPC concrete, development of tensile strength correlated well with the compressive strength of ambient-cured geopolymer concrete. The predictions of tensile strength from compressive strength of ambient-cured geopolymer concrete using the ACI 318 and AS 3600 codes tend to be similar to that for OPC concrete. The predictions are more conservative for heat-cured geopolymer concrete than for ambient-cured geopolymer concrete.
Engineering, Technology and Applied science research/Engineering, Technology and Applied Science Research, 2024
Concrete is used most extensively after water to meet construction requirements. Since the population is increasing day by day, the demand for concrete will always increase, hence, the demand for cement will also increase. The production of cement requires a lot of energy and emits greenhouse gases into the environment. Therefore, an alternative material for cement concrete is required. Geopolymer concrete (GPC) is an alternative to cement made of aluminosilicate materials such as fly ash, Ground Granulated Blast Slag (GGBS), silica fume, metakaolin, etc. If these materials are activated with an alkaline activator, then a bond that is responsible for the strength develops. GPC made with fly ash needs temperature curing to develop its strength, which limits its use on a large scale. In this study, a mix ratio of GPC equivalent to conventional M20 concrete was obtained at ambient curing conditions. The effect of temperature curing was also studied. GPC was prepared in three different mixes. In each mix, the binder content was changed by varying the fly ash and GGBS content. Two sets of cube, beam, and cylindrical samples were prepared from each mixture. One set was cured at ambient temperatures and the other at increased temperatures. The temperature-cured specimens provided higher strength than the ambient-cured. If a strength equivalent to conventional M20 concrete is required for ambient curing, then the mix should be 70% fly ash and 30% GGBS, and the ratio of binder, fine aggregate, and coarse aggregate should be 1:1.5:3.
Strength properties of Fly Ash based Geopolymer Concrete cured at different temperatures
Electronic Journal of Structural Engineering
This paper presents the results of an experimental study of the effect of curing temperature on the compressive strength and split tensile strength of Geopolymer concrete (GPC) which is made using fly ash produced at Norochcholai coal power plant. A relationship between splitting tensile strength and compressive strength also is also developed using test data. The results are then compared with some expressions published in international literature. A mixture of Sodium Silicate and Sodium Hydroxide solutions was used to activate low calcium class F fly ash to form Geopolymers. All specimens were oven cured for 48hours where curing temperature was varied from ambient temperature to 80oC at 20oC intervals. One day of rest period was given to every sample before curing. Test results showed that curing temperature has a significant effect on rate of strength gaining of GPC. The output of this study has provided a better understanding of the correlation between splitting and compressive ...
Applied Sciences
Geopolymer concrete (GPC), also known as an earth friendly concrete, has been under continuous study due to its environmental benefits and potential as a sustainable alternative to conventional concrete construction. However, there is still a lack of comprehensive studies focusing on the influence of all the design mix variables on the fresh and strength properties of GPC. GPC is still a relatively new material in terms of field application and has yet to secure international acceptance as a construction material. Therefore, it is important that comprehensive studies be carried out to collect more reliable information to expand this relatively new material technology to field and site applications. This research work aims to provide a comprehensive study on the factors affecting the fresh and hardened properties of ambient cured fly ash and slag based geopolymer concrete (FS-GPC). Industrial by-products, fly ash from thermal power plants, and ground granulated blast furnace slag fro...
Evaluation of Mechanical Properties of Fly Ash and GGBS Based Geopolymer Concrete
Journal of emerging technologies and innovative research, 2017
Geopolymer concrete is emerging as a promising alternative to conventional concrete. It is produced from by-product materials such as Fly ash (FA), Silica fume, and Ground granulated Blast furnace slag(GGBS), recognized as a low emission alternative binder for concrete. Recent studies have shown that the properties of Geopolymers are mostly similar to those of the OPC binder that is traditionally used for concrete. Geopolymer has limitations of slow setting at ambient temperature which can be eliminated by using GGBS. In the present study, an attempt is made to study the mechanical properties of Geopolymer concrete (GPC) containing GGBS as an additional ingredient. Five mix cases having varying GGBS dosages have been considered to study the mechanical properties. Standard cubes (150 mm), cylinders (150 mm dia. x 300mm. Length) and prisms (100 x 100 x 500 mm) were moulded to evaluate the mechanical properties of Fly Ash and GGBS based Geopolymer concrete. The results of the investiga...
Strength studies on geopolymer concrete with GGBS and Fly ash
IOP Conference Series: Materials Science and Engineering, 2020
Geopolymer concrete is a pollution controlled and eco-friendly alternate material used for construction in the recent years. This concrete has many advantages and applications. The main aim of this study is to check the effect of Fly ash and Ground Granulated Blast Furnace Slag (GGBS) on the mechanical properties of Geopolymer concrete at different replacement levels of GGBS by fly ash from 0 to 25% with 5% variation. From previous researches on Geopolymer concrete, an optimized mix is identified for testing mechanical behaviour. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) of 12 Molarity is used as activator solution in the ratio of 1:2.5. A carboxylic based admixture called La Hypercrete S25 is added in the mix by 1% of the weight of GGBS for increasing the workability of Geopolymer concrete. Cubes of 100mm size are cast for determining the compression strength behavior. Cylinders of 100mm dia and 200mm height are cast for splitting tensile strength and beams of size 500m...
An Experimental Investigation on GGBFS and Fly Ash Based Geopolymer Concrete
Geopolymer is a new development in the world of concrete in which cement is totally replaced by pozzoloanic materials like fly ash and activated by highly alkaline solutions to act as a binder in the concrete mix. Geopolymer concrete utilizes an alternate material including fly ash as binding material in place of cement. As some of the surveys said one tone manufacturing of cement produces nearly one tone of carbon dioxide and which in turn produces greenhouse gases which cause global warming. Present work selects two l industrial by products such as fly ash and ground granulated blast furnace slag (GGBFS) to manufacture geo polymer concrete. Three Molarities of NaOH 8 M, 10 M, 12 M are considered with the replacement of fly ash with GGBFS and as per Indian Standard Specimens are casted and tested at room temperature curing.
Effect of Temperature on Strength Properties of Fly ash based Geopolymer Concrete
The major problem that the earth facing today is the environmental pollution. Within the housing industry mainly the assembly of Portland cement will cause the emission of pollutants ends up in environmental pollution. Globally, the assembly of cement contributes a minimum of 5 to 7% of CO2. We can reduce the pollution effect on environment, by increasing the usage of commercial products in our housing industry. The major problem the globe is facing today is that the environmental pollution. This work carried on studies of temperature effect on strength of fly ash based geopolymer concrete. Geopolymer concrete is manufactured class F fly ash (100%). Sodium silicate solution and sodium hydroxide solution used as alkaline activator.Cubes of size 150mmX150mmX150mm were made at solution to ash ratio of 0.35. All specimens were cured in oven at 50 0 C, 60 0 C, 70 0 C & 80 0 C for different molarities 5M, 7M, 9M for a period of 20 hours. After oven curing, cubes moved to temperature for curing period. The slump cone test was carried to review the workability of concrete. After curing period of 7 days and 28 days UPV test and compressive test were performed. Concluded that different molarity Geopolymer Concrete attains maximum strength at different temperature conditions. Test results show that the 5M, 7M and 9M Geopolymer Concrete has optimum temperature of 70 0 C.
Mix design development of fly ash and ground granulated blast furnace slag based geopolymer concrete
Journal of Building Engineering, 2018
The paper presents a rational mix design methodology to produce fly ash and ground granulated blast furnace slag (GGBS) based geopolymer concrete under ambient temperature curing condition. Efforts are made to develop the mix design by integrating ACI strength versus water to cement ratio curve of normal concrete, absolute volume method and combined grading concept. The proposed mix design methodology is not only user friendly, but offers also an option to choose between the desired compressive strength and specific alkaline activator content, AAC, to binder solids, BS, ratio or vice-versa. Several samples have been cast and are subjected to experimental investigations in order to produce concrete of required strength and properties. Strength attained by the geopolymer concrete for similar AAC to BS ratio that mimics water to cement ratio of normal concrete has found to be significantly high, in the range from 66 to 32 MPa for AAC to BS ratio from 0.4 to 0.8, respectively. Attempts are also made to propose a modified strength versus AAC to BS ratio curve based on the obtained test results. Finally, the mix design methodology has been depicted in the form of a flow chart, and its usefulness is illustrated with the help of an example.
Effect of curing condition on the mechanical properties of fly ash-based geopolymer concrete
SN Applied Sciences
In the present study, the mechanical properties of geopolymer concrete (GPC) has been investigated. GPC represents a novel technology that is giving significant concern in industrial construction, especially in term of the current emphasis on sustainability. In this study, the NaOH and Na 2 SiO 3 solutions were used as an alkaline solution in all GPC mixes. Na 2 SiO 3 with 10 concentration of molarity, activator-to-FA ratio of 0.4, Na 2 SiO 3 /NaOH ratio of 1.75, and two curing regimes viz., ambient curing, and heat curing at 75 °C for 26 h were employed. The experimental results indicated that the geopolymer concrete strengths, modulus of elasticity, and other mechanical properties increased with heat curing as compared to ambient temperature curing. The elastic modulus of GPC was associated with the compressive strengths and similar to those of OPC concrete. Furthermore, the geopolymer concrete mixture requires proper mix proportion and temperaturecontrolled curing conditions to accomplish good results.