Development of sustainable construction material from fly ash class C

2020 ◽  
Vol 18 (6) ◽  
pp. 1615-1640
Author(s):  
Eric Asa ◽  
Monisha Shrestha ◽  
Edmund Baffoe-Twum ◽  
Bright Awuku
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Alkaline Solution ◽  
Sustainable Construction ◽  
Geopolymer Concrete ◽  
Curing Time ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Content Type

Purpose Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for the environment. Also, fly ash is a material with sustainable properties. Therefore, this paper aims to focus on the development of sustainable construction materials using 100% high-calcium fly ash and potassium hydroxide (KOH)-based alkaline solution and study the engineering properties of the resulting fly ash-based geopolymer concrete. Laboratory tests were conducted to determine the mechanical properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In phase I of the study, carbon nanotubes (CNTs) were added to determine their effect on the strength of the geopolymer mortar. The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce similar (comparable) strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates a considerable amount of heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond was unable to form a stronger bond. This study also determined that the addition of CNTs to the mix makes the geopolymer concrete tougher than the traditional concrete without CNT. Design/methodology/approach Tests were conducted to determine properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In Phase I of the study, CNTs were studied to determine their effect on the strength of the geopolymer mortar. Findings The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce the same strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates too much heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond. This study also determined that the addition of CNTs to the mix makes the concrete tougher than concrete without CNT. Originality/value This study was conducted at the construction engineering and management concrete laboratory at North Dakota State University in Fargo, North Dakota. All the experiments were conducted and analyzed by the authors.

scholarly journals Durability Study on High Calcium Fly Ash Based Geopolymer Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ganesan Lavanya ◽  
Josephraj Jegan
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Sodium Hydroxide ◽  
Ordinary Portland Cement ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Ordinary Portland Cement Concrete

This study presents an investigation into the durability of geopolymer concrete prepared using high calcium fly ash along with alkaline activators when exposed to 2% solution of sulfuric acid and 5% magnesium sulphate for up to 45 days. The durability was also assessed by measuring water absorption and sorptivity. Ordinary Portland cement concrete was also prepared as control concrete. The grades chosen for the investigation were M20, M40, and M60. The alkaline solution used for present study is the combination of sodium silicate and sodium hydroxide solution with the ratio of 2.50. The molarity of sodium hydroxide was fixed as 12. The test specimens were150×150×150 mm cubes,100×200 mm cylinders, and100×50 mm discs cured at ambient temperature. Surface deterioration, density, and strength over a period of 14, 28, and 45 days were observed. The results of geopolymer and ordinary Portland cement concrete were compared and discussed. After 45 days of exposure to the magnesium sulfate solution, the reduction in strength was up to 12% for geopolymer concrete and up to 25% for ordinary Portland cement concrete. After the same period of exposure to the sulphuric acid solution, the compressive strength decrease was up to 20% for geopolymer concrete and up to 28% for ordinary Portland cement concrete.

High-Volume Fly Ash Concrete for Sustainable Construction

2012 ◽  
Vol 512-515 ◽  
pp. 2976-2981 ◽  
Author(s):  
Jeffery S. Volz
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
High Volume ◽  
Sustainable Construction ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Fly Ash Concrete ◽  
Worldwide Production ◽  
High Volume Fly Ash ◽  
Green Solution

With worldwide production of fly ash approaching 800 million tonnes annually, increasing the amount of fly ash used in concrete will remove more material from the solid waste stream and reduce the amount ending up in landfills. However, most specifications limit the amount of cement replacement with fly ash to less than 25 or 30%. Concrete with fly ash replacement levels of at least 50% – referred to as high-volume fly ash (HVFA) concrete – offers a potential green solution. The following study investigated the structural performance of HVFA concrete compared to conventional portland-cement concrete. Specifically, the research examined both the bond strength of reinforcing steel in HVFA concrete as well as the shear behavior of HVFA reinforced concrete. The results indicate that HVFA concrete performs as well or better than conventional portland-cement concrete.

Proportioning of concrete mixes incorporating fly ash

1976 ◽  
Vol 3 (1) ◽  
pp. 68-82 ◽  
Author(s):  
Ram S. Ghosh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio

A method is described for proportioning fly ash concretes to produce similar compressive strengths as normal Portland cement concrete at 3, 7, 28, and 90 days. The method is primarily based on the Abrams' law relating compressive strength and water–cement ratio. Curves are also presented, for estimating the most economical fly ash to cement ratio for a particular strength and cost of fly ash.

Effect of Curing Time on the Pore Structure of the Portland Cement Concrete

2010 ◽  
Vol 44-47 ◽  
pp. 2592-2596
Author(s):  
Wei Lun Wang ◽  
Peng Liu
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Curing Time ◽  
Hydration Products ◽  
Portland Cement Concrete ◽  
X Ray Diffraction ◽  
Cement Concrete ◽  
X Ray

In this paper, the influence of curing time on the compressive strength and pore structure of the Portland cement concrete was investigated. The phase composition and morphology of hydration products of Portland cement were analyzed with X-ray diffraction (XRD). In addition, the porosity and pore distribution of the concrete were also researched using mercury intrusion porosimetry (MIP), surface area and porosity analyzer (BET). The results show that the influence of curing time on the compressive strength and pore structure of the concrete is obvious. With curing time increasing, the compressive strength of the concrete increased and the porosity decreased. The corresponding fractal dimension of the pore and the microstructure were changed, as well. With time increasing, more hydration products were produced.

Review on Alkali-Activated Fly Ash Based Geopolymer Concrete

2016 ◽  
Vol 841 ◽  
pp. 162-169 ◽  
Author(s):  
Kefiyalew Zerfu ◽  
Januarti Jaya Ekaputri
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Construction Material ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Carbon Credit ◽  
Cement Concrete ◽  
Carbon Dioxide Co2 ◽  
Alkali Activated ◽  
Better Than

Due to environmental pollution form cement industries, some efforts for alternative construction material are increasing. Recently, geopolymer concrete has drawn attention of researchers and engineers because of its lower carbon print and better mechanical property over Portland cement concrete. According to previous studies, geopolymer concrete results almost up to 90% reduction in carbon dioxide (CO2) emission to atmosphere. Mechanical properties of geopolymer concrete such as compressive strength, durability, sulfate resistance, early strength and low shrinkage are better than Portland cement concrete. In addition, the appropriate usage of one ton of fly ash earns one carbon-credit redemption value of about 20 Euros, and hence earned monetary benefits through carbon-credit trade.Therefore, this paper presents a review on the fly ash-based geopolymer concrete. The paper mainly covers composition, mixing and curing process, benefits, limitations and applications of alkali activated fly ash based geopolymer concrete.

Improving the structural performance of reinforced geopolymer concrete incorporated with hazardous heavy metal waste ash

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Suresh Kumar Arunachalam ◽  
Muthukannan Muthiah ◽  
Kanniga Devi Rangaswamy ◽  
Arunkumar Kadarkarai ◽  
Chithambar Ganesh Arunasankar
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Medical Waste ◽  
Source Material ◽  
Geopolymer Concrete ◽  
Deformation Capacity ◽  
Cement Concrete ◽  
Content Type ◽  
Load Carrying ◽  
Reinforced Cement

Purpose Demand for Geopolymer concrete (GPC) has increased recently because of its many benefits, including being environmentally sustainable, extremely tolerant to high temperature and chemical attacks in more dangerous environments. Like standard concrete, GPC also has low tensile strength and deformation capacity. This paper aims to analyse the utilization of incinerated bio-medical waste ash (IBWA) combined with ground granulated blast furnace slag (GGBS) in reinforced GPC beams and columns. Medical waste was produced in the health-care industry, specifically in hospitals and diagnostic laboratories. GGBS is a form of industrial waste generated by steel factories. The best option to address global warming is to reduce the consumption of Portland cement production and promote other types of cement that were not a pollutant to the environment. Therefore, the replacement in ordinary Portland cement construction with GPC is a promising way of reducing carbon dioxide emissions. GPC was produced due to an alkali-activated polymeric reaction between alumina-silicate source materials and unreacted aggregates and other materials. Industrial pollutants such as fly ash and slag were used as raw materials. Design/methodology/approach Laboratory experiments were performed on three different proportions (reinforced cement concrete [RCC], 100% GGBS as an aluminosilicate source material in reinforced geopolymer concrete [GRGPC] and 30% replacement of IBWA as an aluminosilicate source material for GGBS in reinforced geopolymer concrete [IGRGPC]). The cubes and cylinders for these proportions were tested to find their compressive strength and split tensile strength. In addition, beams (deflection factor, ductility factor, flexural strength, degradation of stiffness and toughness index) and columns (load-carrying ability, stress-strain behaviour and load-deflection behaviours) of reinforced geopolymer concrete (RGPC) were studied. Findings As shown by the results, compared to Reinforced Cement Concrete (RCC) and 100% GGBS based Reinforced Geopolymer Concrete (GRGPC), 30% IBWA and 70% GGBS based Reinforced Geopolymer Concrete (IGRGPC) (30% IBWA–70% GGBS reinforced geo-polymer concrete) cubes, cylinders, beams and columns exhibit high compressive strength, tensile strength, flexural strength, load-carrying ability, ultimate strength, stiffness, ductility and deformation capacity. Originality/value All the results were based on the experiments done in this research. All the result values obtained in this research are higher than the theoretical values.

Low Cement/High Fly Ash Concretes: Their Properties and Response to Chemical Admixtures

1987 ◽  
Vol 113 ◽  
Author(s):  
V. H. Dodson
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Calcium Hydroxide ◽  
Pozzolanic Reaction ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Fly Ashes ◽  
Chemical Admixtures ◽  
Reaction With Water

ABSTRACTIn practice, the amount of fly ash added to portland cement concrete varies depending upon the desired end properties of the concrete. Generally, when a given portland cement concrete is redesigned to include fly ash, between 10 and 50% of the cement is replaced by a volume of fly ash equal to that of the cement. Sometimes as much as twice the volume of the cement replaced, although 45.4 kg (100 lbs) of cement will only produce enough calcium hydroxide during its reaction with water to react with about 9 kg (20 lbs) of a typical fly ash. The combination of large amounts of certain fly ashes with small amounts of portland cement in concrete has been found to produce surprisingly high compressive strengths, which cannot be accounted for by the conventional “pozzolanic reaction”. Ratios of cement to fly ash as high as 1:15 by weight can produce compressive strengths of 20.7 MPa (3,000 psi) at I day and over 41.4 MPa (6,000 psi) at 28 days. Methods of identifying these “hyperactive” fly ashes along with some of the startling results, with and without chemical admixtures are described.

Acid Attack Resistance of Magnesium Phosphate Cement

2016 ◽  
Vol 680 ◽  
pp. 392-397
Author(s):  
Zhu Ding ◽  
Meng Xi Dai ◽  
Can Lu ◽  
Ming Jie Zhang ◽  
Peng Cui
Keyword(s):  
Compressive Strength ◽  
Acid Solution ◽  
Portland Cement ◽  
Magnesium Phosphate ◽  
Acid Solutions ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Acid Attack ◽  
High Acid ◽  
Repair Materials

Magnesium phosphate cements (MPC) had been used as repair materials for deteriorated Portland cement concrete structures. In this paper a new MPC was prepared and the basic properties including workability and compressive strength were tested. The acid attack resistance of MPC was investigated by immersing the MPC mortars in solutions at pH 3, 5, and 7, for 14d, 28d and 60d respectively. The compressive strength of MPC mortars after acid attack was tested and the microstructure of MPC were examined. The results showed that the compressive strength of MPC decreased after immersion in acid solution for 14d and 28d, however the strength of MPC with suitable materials mixture can recovered again after 60d immersion. The results indicated MPC has high acid attack resistance in static acid solution. The behavior of MPC in flowing acid solutions is need to be studied further.

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