• Title/Summary/Keyword: geopolymer concrete

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Feasibility study of ambient cured geopolymer concrete -A review

  • Jindal, Bharat Bhushan
    • Advances in concrete construction
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    • v.6 no.4
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    • pp.387-405
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    • 2018
  • Geopolymer concrete is a fastest developing field of research for utilizing industrial and agro waste materials as an alternative for Portland cement based concrete. Geopolymers are formed by the alkaline activation of aluminosilicates rich materials termed as geopolymerization. The process of geopolymerization requires elevated temperature curing which restricts its application to precast industry. This review summarizes the work carried out on developing the geopolymer concrete with the addition of various mineral admixtures at ambient curing temperature conditions. An overview of studies promoting the geopolymer concrete in general building construction is presented. Literature study revealed that geopolymer concrete with the addition of admixtures can exhibit desirable properties at ambient temperature conditions.

An Experiment on Bond Behaviours of Reinforcements Embedded in Geopolymer Concrete Using Direct Pull-out Test (직접 인발 시험을 이용한 지오폴리머 콘크리트의 부착 특성 실험)

  • Kim, Jee-Sang;Park, Jong-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.454-462
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    • 2016
  • Geopolymer concrete is a new class of construction materials that has emerged as an alternative to ordinary Portland cement concrete to reduce the emission of $CO_2$ in the production of concrete. Many researches have been carried out on material developments of geopolymer concrete, however a few studies have been reported on the structural use of them. This paper presents an experiment on the bond behaviors of reinforcements embedded in fly ash based geopolymer concrete. The development lengths of reinforcement for various compressive strength levels of geopolymer concrete, 20, 30 and 40 MPa, and reinforcement diameters, 10, 16 and 25 mm, are investigated. Total 27 specimens were manufactured and pull-out test according to EN 10080 was applied to measure the bond strength and slips between concrete and reinforcements. As the compressive strength levels of geopolymer concrete increase, the bond strength between geopolymer concrete and reinforcement increase. The bond strengths decrease as the diameters of reinforcements increase, which is similar in normal concrete. Also, an estimation equation for the basic development length of reinforcement embedded in geopolymer concrete is proposed based on the experimental results in this study.

Improving compressive strength of low calcium fly ash geopolymer concrete with alccofine

  • Jindal, Bharat Bhushan;Singhal, Dhirendra;Sharma, Sanjay K.;Ashish, Deepankar K.;Parveen, Parveen
    • Advances in concrete construction
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    • v.5 no.1
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    • pp.17-29
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    • 2017
  • Geopolymer concrete is environmentally friendly and could be considered as a construction material to promote the sustainable development. In this paper fly ash based geopolymer concretes with different percentages of alccofine were made by mixing sodium hydroxide and sodium silicate as an alkaline activator and cured at ambient as well as heat environment in an electric oven at $90^{\circ}C$. Effects of various parameters such as the percentage of alccofine, curing temperature, a period of curing, fly ash content, was studied on compressive strength as well as workability of geopolymer concrete. The study concludes that the presence of alccofine improves the properties of geopolymer concrete during a fresh and hardened state of concrete. Geopolymer concrete in the presence of alccofine can be used for the general purpose of concrete as required compressive strength can be achieved even at ambient temperature. The 28 days compressive strength of 73 MPa, when cured at 90-degree Celsius, confirmed that it is also very suitable for precast concrete components.

Mechanical and durability of geopolymer concrete containing fibers and recycled aggregate

  • Abdelaziz Yousuf, Mohamed;Orhan, Canpolat;Mukhallad M., Al-Mashhadani
    • Computers and Concrete
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    • v.30 no.6
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    • pp.421-432
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    • 2022
  • Recently, the interminable ozone depletion and the global warming concerns has led to construction industries to seek for construction materials which are eco-friendly. Regarding this, Geopolymer Concrete (GPC) is getting great interest from researchers and scientists, since it can operate by-product waste to replace cement which can lead to the reduction of greenhouse gas emission through its production. Also, compared to ordinary concrete, geopolymer concrete belongs improved mechanical and durability properties. In spite of its positive properties, the practical use of geopolymer concrete is currently limited. This is primarily owing to the scarce structural, design and application knowledge. This study investigates the Mechanical and Durability of Geopolymer Concrete Containing Fibers and Recycled Aggregate. Mixtures of elastoplastic fiber reinforced geopolymer concrete with partial replacement of recycled coarse aggregate in different proportions of 10, 20, 30, and 40% with natural aggregate were fabricated. On the other hand, geopolymer concrete of 100% natural aggregate was prepared as a control specimen. To consider both strength and durability properties and to evaluate the combined effect of recycled coarse aggregate and elastoplastic fiber, an elastoplastic fiber with the ratio of 0.4% and 0.8% were incorporated. The highest compressive strength achieved was 35 MPa when the incorporation of recycled aggregates was 10% with the inclusion of 0.4% elastoplastic fiber. From the result, it was noticed that incorporation of 10% recycled aggregate with 0.8% of the elastoplastic fiber is the perfect combination that can give a GPC having enhanced tensile strength. When specimens exposed to freezing-thawing condition, the physical appearance, compressive strength, weight loss, and ultrasonic pulse velocity of the samples was investigated. In general, all specimens tested performed resistance to freezing thawing. the obtained results indicated that combination of recycled aggregate and elastoplastic fiber up to some extent could be achieved a geopolymer concrete that can replace conventional concrete.

Compressive Behaviour of Geopolymer Concrete-Filled Steel Columns at Ambient and Elevated Temperatures

  • Tao, Zhong;Cao, Yi-Fang;Pan, Zhu;Hassan, Md Kamrul
    • International Journal of High-Rise Buildings
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    • v.7 no.4
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    • pp.327-342
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    • 2018
  • Geopolymer concrete (GPC), which is recognised as an environmentally friendly alternative to ordinary Portland cement (OPC) concrete, has been reported to possess high fire resistance. However, very limited research has been conducted to investigate the behaviour of geopolymer concrete-filled steel tubular (GCFST) columns at either ambient or elevated temperatures. This paper presents the compressive test results of a total of 15 circular concrete-filled steel tubular (CFST) stub columns, including 5 specimens tested at room temperature, 5 specimens tested at elevated temperatures and the remaining 5 specimens tested for residual strength after exposure to elevated temperatures. The main variables in the test program include: (a) concrete type; (b) concrete strength; and (c) curing condition of geopolymer concrete. The test results demonstrate that GCFST columns have similar ambient temperature behaviour compared with the conventional CFST counterparts. However, GCFST columns exhibit better fire resistance than the conventional CFST columns. Meanwhile, it is found that the GCFST column made with heat cured GPC has lower strength loss than other columns after exposure to elevated temperatures. The research results highlight the possibility of using geopolymer concrete to improve the fire resistance of CFST columns.

Behavior of geopolymer and conventional concrete beam column joints under reverse cyclic loading

  • Raj, S. Deepa;Ganesan, N.;Abraham, Ruby;Raju, Anumol
    • Advances in concrete construction
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    • v.4 no.3
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    • pp.161-172
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    • 2016
  • An experimental investigation was carried out on the strength and behavior plain and fiber reinforced geopolymer concrete beam column joints and the results were compared with plain and steel fiber reinforced conventional concrete beam column joints. The volume fraction of fibers used was 0.5%. A total of six Geopolymer concrete joints and four conventional concrete joints were cast and tested under reversed cyclic loading to evaluate the performance of the joints. First crack load, ultimate load, energy absorption capacity, energy dissipation capacity stiffness degradation and moment-curvature relation were evaluated from the test results. The comparison of test results revealed that the strength and behavior of plain and fiber reinforced geopolymer concrete beam column joints are marginally better than corresponding conventional concrete beam column joints.

Mechanical Properties of Fly Ash Geopolymer Concrete Incorporating Bamboo Ash (대나무 재를 혼합한 플라이에쉬 지오폴리머 콘크리트의 물리적 특성에 대한연구)

  • Ishak, Shafiq;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.33-34
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    • 2019
  • Malaysia, as a tropical rainforest country, enjoys an abundance of bamboo plant that proliferate throughout the country. The application of geopolymer technology has become a trend and preserve the environment from harm. Fly ash geopolymer concrete has low early strength and requires 24 hours for the concrete to harden. Thus, the presence of calcium and potassium content in bamboo ash could remedy this problem. Besides, there is no research regarding the use of bamboo ash as a binder in geopolymer concrete. Therefore, the presence of bamboo ash could improve the research field with the use of agriculture waste in a building construction. This research aim is to use bamboo ash in the production of fly ash geopolymer concrete. The specimens were casted in $100mm{\times}100mm{\times}100mm$ cubes and sodium based activator were used as the alkaline solutions. The binders are formulated with different binder ratio. All test specimens were cured at ambient temperature ($23^{\circ}C-25^{\circ}C$) and 100% fly ash was chosen as control specimen. To determine the mechanical properties of fly sh geopolymer concrete with the presence of bamboo ash, compressive strength test was conducted. The test results depicted that as the percentage of bamboo ash decreases, compressive strength increases. Also, the addition of 5% of bamboo ash into fly ash geopolymer concrete could improve the early strength in 7 days. The results were proven with the result explained by X-ray fluorescence (XRF) and X-ray diffraction (XRD). Therefore, it can be concluded that the addition of bamboo ash improved the properties of fly ash geopolymer concrete at early ages.

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Prediction of the compressive strength of fly ash geopolymer concrete using gene expression programming

  • Alkroosh, Iyad S.;Sarker, Prabir K.
    • Computers and Concrete
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    • v.24 no.4
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    • pp.295-302
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    • 2019
  • Evolutionary algorithms based on conventional statistical methods such as regression and classification have been widely used in data mining applications. This work involves application of gene expression programming (GEP) for predicting compressive strength of fly ash geopolymer concrete, which is gaining increasing interest as an environmentally friendly alternative of Portland cement concrete. Based on 56 test results from the existing literature, a model was obtained relating the compressive strength of fly ash geopolymer concrete with the significantly influencing mix design parameters. The predictions of the model in training and validation were evaluated. The coefficient of determination ($R^2$), mean (${\mu}$) and standard deviation (${\sigma}$) were 0.89, 1.0 and 0.12 respectively, for the training set, and 0.89, 0.99 and 0.13 respectively, for the validation set. The error of prediction by the model was also evaluated and found to be very low. This indicates that the predictions of GEP model are in close agreement with the experimental results suggesting this as a promising method for compressive strength prediction of fly ash geopolymer concrete.

Development of eco-friendly concrete produced with Rice Husk Ash (RHA) based geopolymer

  • Annadurai, Shalini;Rathinam, Kumutha;Kanagarajan, Vijai
    • Advances in concrete construction
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    • v.9 no.2
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    • pp.139-147
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    • 2020
  • This paper reports the effect of Rice Husk Ash (RHA) in geopolymer concrete on strength, durability and microstructural properties under ambient curing at a room temperature of 25℃ and 65±5% relative humidity. Rice husk was incinerated at 800℃ in a hot air oven. and ground in a ball mill to achieve the required fineness. RHA was partially added in 10, 15, 20, 25, 30 and 35 percentages to fly ash with 10% of GGBS to produce geopolymer concrete. Test results exhibit that the substitution of RHA in geopolymer concrete resulted in reduced strength properties during initial curing. In the initial stage, workability of GPC mixes was affected by RHA particles due to the presence of dormant particles in it. It is evident from the microstructural study that the presence of RHA particles densifies the matrix reducing porosity in concrete. This is due to the presence of RHA in geopolymer concrete, which affects the ratio of silica and alumina, resulting in polycondensation reactions products. This study suggests that incorporation of rice husk ash in geopolymer concrete is the solution for effective utilization of waste materials and prevention of environmental pollution due to the dumping of industrial waste and to produce eco-friendly concrete.

An experimental investigation on the mechanical properties of steel fiber reinforced geopolymer concrete

  • Murali, Kallempudi;Meena, T.
    • Advances in concrete construction
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    • v.12 no.6
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    • pp.499-505
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    • 2021
  • Geopolymer binders fascinate the attention of researchers as a replacement to cement binder in conventional concrete. One-ton production of cement releases one ton of carbon-dioxide in the atmosphere. In the replacement of cement by geopolymer material, there are two advantages: one is the reduction of CO2 in the atmosphere, second is the utilization of Fly ash and Ground granulated blast furnace slag (GGBFS) are by-products from coal and steel industries. This paper focuses on the mechanical properties of steel fiber reinforced geopolymer concrete. The framework considered in this research work is geopolymer source (Fly ash, GGBFS and crimped steel fibre) and alkaline activator which consists of NaOH and Na2SiO3 of molarity 8M. Here the Na2SiO3 / NaOH ratio was taken as 2.5. The variables considered in this experimental work include Binder content (360,420 and 450 kg/m3), the proportion of Fly ash and GGBS (70-30, 60-40 and 50-50) for three different grades of Geopolymer concrete (GPC) GPC 20, GPC 40 and GPC 60. The percentage of crimped steel fibres was varied as 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. Generally, the inclusion of steel fibres increases the flexural and split tensile strength of Geopolymer concrete. The optimum dosage of steel fibres was found to be 0.4% (by volume fraction).