scholarly journals Utilization of High Calcium Content Fly Ash: Flexural Strength of Geopolymer Concrete Beams in Sea Water Environment

2016 ◽  
Vol 10 (1) ◽  
pp. 782-793 ◽  
Author(s):  
Ridho Bayuaji ◽  
M Sigit Darmawan ◽  
Boedi Wibowo ◽  
NA Husin ◽  
Srie Subekti
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Sea Water ◽  
Water Environment ◽  
Calcium Content ◽  
High Heat ◽  
Geopolymer Concrete ◽  
High Calcium ◽  
Chloride Environment

This paper presents a study of the flexural strength of geopolymer concrete beam using high calcium content fly ash (FA) in marine environment, without high heat curing. Two series of beam specimens were loaded to failure to study the effect of chloride environment on the flexural strength of geopolymer concrete beams. Series I specimens were subjected to sea environment, whereas series II were kept at room temperature. Tests performed on concrete cylinders show that the sea water has no effect on compressive and splitting tensile stress of high calcium content FA based geopolymer concrete. However, the ratio of splitting and compressive strength for both series was approximately 44%, almost double than that of normal concrete. In addition, the flexural test of concrete beams shows that the average cracking load for series I specimens was 275% higher than that of series II. However, the ultimate load, crack pattern and deflection characteristic for both series were very similar.

scholarly journals Shear Strength of Geopolymer Concrete Beams Using High Calcium Content Fly Ash in a Marine Environment

Buildings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 98 ◽  
Author(s):  
Muhammad Sigit Darmawan ◽  
Ridho Bayuaji ◽  
Hidajat Sugihardjo ◽  
Nur Ahmad Husin ◽  
Raden Buyung Anugraha Affandhie
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Marine Environment ◽  
Sea Water ◽  
Calcium Content ◽  
Shear Load ◽  
Geopolymer Concrete ◽  
Loading Test ◽  
High Calcium ◽  
Concrete Resistivity

This paper deals with the behavior of a geopolymer concrete beam (GCB) under shear load using high calcium content fly ash (FA). The effect of the marine environment on the shear strength of GCB was considered by curing the specimen in a sea splashing zone for 28 days. Destructive and non-destructive tests were carried out to determine the properties of geopolymer concrete in different curing environments. Geopolymer concretes cured at room temperature showed higher compressive strength, slightly lower porosity, and higher concrete resistivity than that of those cured in sea water. From the loading test of the GCB under shear load, there was no effect of a sea environment on the crack pattern and crack development of the beam. The shear strength of the GCB generally exceeded the predicted shear strength based on the American Concrete Institute (ACI) Code.

scholarly journals Pengaruh Penambahan Serat Kawat Bendrat Terhadap Kuat Lentur Beton Geopolimer

2022 ◽  
Vol 10 (1) ◽  
pp. 69-76
Author(s):  
Indrayani Indrayani ◽  
Lina Flaviana Tilik ◽  
Djaka Suhirkam ◽  
Suhadi Suhadi ◽  
Muhammad Prawira Wardana ◽  
...  
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Tensile Load ◽  
Strength Test ◽  
Coal Waste ◽  
Geopolymer Concrete ◽  
Normal Concrete ◽  
Additional Material ◽  
Flexible Beams

Currently, innovation continues to be developed to replace cement with other materials so that the use of cement as a building material can be reduced. Utilization of coal waste (fly ash) is an alternative to subtitude cement. From previous studies, fly ash mixed with alkaline materials in the form of NaOH and Na2SiO3 in a ratio of 1:5 can produce geopolymer concrete. This geopolymer concrete research was continued by adding bendrat wire fibers into the geopolymer concrete mixture. The method used in testing the aggregate, testing the compressive strength of normal concrete K225, testing the flexural strength of normal concrete and geopolymer concrete refers to SNI. Another additional material that is mixed is bendrat wire fiber. The research was carried out in the form of making flexible beams of 10 cm x 10 cm x 50 cm with fiber variations of 0%, 0.5%, and 1,0% at the age of 14 and 28 days. The results of the flexural strength test of the BN beam at the age of 28 days can withstand loads than BG. The average flexural strength obtained with variations of BN, BN+SB 0.5% and BN+SB 1.0% respectively were 2.796 MPa, 3.113 MPa, and 3.879 MPa. The results of testing the average flexural strength of geopolymer concrete beams at 28 days, obtained variations of BG, BG+SB 0.5%, and BG+SB 1.0% respectively were 0 MPa, 0.055 MPa and 0.104 MPa. In addition, geopolymer concrete cannot be used as a beam and the addition of bendrat wire fiber to geopolymer concrete cannot withstand the tensile load on the concrete.

Strength and Behaviour of Small-Scale Reinforced High Calcium Fly Ash Geopolymer Concrete Beam with Short Shear Span

2016 ◽  
Vol 718 ◽  
pp. 191-195
Author(s):  
Pattanapong Topark-Ngarm ◽  
Trinh Cao ◽  
Prinya Chindaprasirt ◽  
Vanchai Sata
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Small Scale ◽  
Geopolymer Concrete ◽  
Rc Beams ◽  
High Calcium ◽  
High Calcium Fly Ash

The small-scale reinforced high calcium fly ash geopolymer concrete beams with short shear span were studied in this research. Reinforced concrete beams with 150x150 mm2 cross-section and 530 mm in length were used for tests. Conventional reinforced Portland cement concrete beams (RC) with designed concrete compressive strengths of 35, 45 and 55 MPa and high-calcium fly ash geopolymer reinforced concrete beams with similar strength were tested. The geopolymer concretes (GC) were designed with alkaline liquid to fly ash ratio (L/A) of 0.5, sodium silicate to sodium hydroxide (S/H) ratio of 1.0 and two sodium hydroxide (NaOH) concentrations of 10M and 15M. Two temperatures of 23 and 60 °C were used for curing geopolymer reinforced concrete (GRC) beams for 24 hr, while RC beams were moist cured at 23 °C. The maximum sustained moment and shear were compared with the predicted values from the RC-design standard. The results showed that the failure patterns of small GRC beams were different to that of normal RC beam. The small GRC beams failed in flexure whereas the similar small RC beams failed in shear. However, the GRC beams were able to sustain higher shear and moment than the values obtained from the design code. The different in failure mechanism was probably due to the different in modulus of elasticity of geopolymer concrete and normal concrete.

scholarly journals Assessment of the Rheological and Mechanical Properties of Geopolymer Concrete Comprising Fly Ash and Fluid Catalytic Cracking Residue as Aluminosilicate Precursor

2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
High Alumina ◽  
Geopolymer Concrete ◽  
Sem Images

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.

scholarly journals Novel Analytical Method for Mix Design and Performance Prediction of High Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 900
Author(s):  
Chamila Gunasekara ◽  
Peter Atzarakis ◽  
Weena Lokuge ◽  
David W. Law ◽  
Sujeeva Setunge
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Gradient Algorithm ◽  
Geopolymer Concrete ◽  
Statistical Regression ◽  
Solid Ratio ◽  
Marquardt Algorithm ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Matlab Programming

Despite extensive in-depth research into high calcium fly ash geopolymer concretes and a number of proposed methods to calculate the mix proportions, no universally applicable method to determine the mix proportions has been developed. This paper uses an artificial neural network (ANN) machine learning toolbox in a MATLAB programming environment together with a Bayesian regularization algorithm, the Levenberg-Marquardt algorithm and a scaled conjugate gradient algorithm to attain a specified target compressive strength at 28 days. The relationship between the four key parameters, namely water/solid ratio, alkaline activator/binder ratio, Na2SiO3/NaOH ratio and NaOH molarity, and the compressive strength of geopolymer concrete is determined. The geopolymer concrete mix proportions based on the ANN algorithm model and contour plots developed were experimentally validated. Thus, the proposed method can be used to determine mix designs for high calcium fly ash geopolymer concrete in the range 25–45 MPa at 28 days. In addition, the design equations developed using the statistical regression model provide an insight to predict tensile strength and elastic modulus for a given compressive strength.

scholarly journals Resistance to Sulfuric Acid Corrosion of Geopolymer Concrete Based on Different Binding Materials and Alkali Concentrations

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7109
Author(s):  
Wei Yang ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang ◽  
Wei Ge ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Fly Ash ◽  
Acid Corrosion ◽  
Geopolymer Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Naoh Solution ◽  
Sulfuric Acid Corrosion

Geopolymer binder is expected to be an optimum alternative to Portland cement due to its excellent engineering properties of high strength, acid corrosion resistance, low permeability, good chemical resistance, and excellent fire resistance. To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with different binding materials and concentrations of sodium hydroxide solution (NaOH), metakaolin, high-calcium fly ash, and low-calcium fly ash were chosen as binding materials of GPC for the geopolymerization process. A mixture of sodium silicate solution (Na2SiO3) and NaOH solution with different concentrations (8 M and 12 M) was selected as the alkaline activator with a ratio (Na2SiO3/NaOH) of 1.5. GPC specimens were immersed in the sulfuric acid solution with the pH value of 1 for 6 days and then naturally dried for 1 day until 98 days. The macroscopic properties of GPC were characterized by visual appearance, compressive strength, mass loss, and neutralization depth. The materials were characterized by SEM, XRD, and FTIR. The results indicated that at the immersion time of 28 d, the compressive strength of two types of fly ash-based GPC increased to some extent due to the presence of gypsum, but this phenomenon was not observed in metakaolin-based GPC. After 98 d of immersion, the residual strength of fly ash based GPC was still higher, which reached more than 25 MPa, while the metakaolin-based GPC failed. Furthermore, due to the rigid 3D networks of aluminosilicate in fly ash-based GPC, the mass of all GPC decreased slightly during the immersion period, and then tended to be stable in the later period. On the contrary, in metakaolin-based GPC, the incomplete geopolymerization led to the compressive strength being too low to meet the application of practical engineering. In addition, the compressive strength of GPC activated by 12 M NaOH was higher than the GPC activated by 8 M NaOH, which is owing to the formation of gel depended on the concentration of alkali OH ion, low NaOH concentration weakened chemical reaction, and reduced compressive strength. Additionally, according to the testing results of neutralization depth, the neutralization depth of high-calcium fly ash-based GPC activated by 12 M NaOH suffered acid attack for 98 d was only 6.9 mm, which is the minimum value. Therefore, the best performance was observed in GPC prepared with high-calcium fly ash and 12 M NaOH solution, which is attributed to gypsum crystals that block the pores of the specimen and improve the microstructure of GPC, inhibiting further corrosion of sulfuric acid.

Structural Behaviour of Green Geopolymer Concrete Beams and Columns Made with Waste Wood Ash a Partial Substitution Binder

2022 ◽  
Vol 1048 ◽  
pp. 333-344
Author(s):  
K. Kumar Arun ◽  
M. Muthukannan ◽  
R. Raja Abinaya ◽  
A. Kumar Suresh
Keyword(s):  
Fly Ash ◽  
Concrete Beams ◽  
Wood Ash ◽  
Partial Substitution ◽  
Polymer Concrete ◽  
Geopolymer Concrete ◽  
Structural Behaviour ◽  
Waste Wood ◽  
Toughness Index ◽  
Load Carrying

On the demand of reducing the global warming due to cement production which is used as main constituent in the production of concrete and minimizing the environmental impact caused by the waste and its disposal methods, this study was aimed. This study looked in to detail insight view on effective utilization of waste wood ash in the production of geopolymer concrete beams and columns to alternate the conventional reinforced concrete elements in construction industry. Waste wood ash is a waste by product produced in the nearby hotel and factories by burning the waste wood collected from timber industries and the ash are thrown in to land which creates a major environmental pollution. Geopolymer is a novel inorganic eco-friendly binding agent derived from alkaline solution that stimulates aluminosilicate source material (such as metakaolin, fly ash and GGBS). In this research, behaviour of beams in deflection, ductility factor, flexural strength and toughness index and columns in load carrying ability, stress strain behaviour and load-deflection behaviours were examined for three types of concretes (30% WWA – 70% Fly ash Geo-polymer concrete, Fly ash Geo-polymer concrete and Reinforced Cement Concrete). The results showed that inclusion of waste wood ash in geopolymer concrete helped in enhancing the load carrying capacity of beam and column by 42% and 28%. Further, the behaviour of structural elements in stiffness, ductility and toughness were also improved with the replacement of waste wood ash.

Pervious high-calcium fly ash geopolymer concrete

2012 ◽  
Vol 30 ◽  
pp. 366-371 ◽  
Author(s):  
Tawatchai Tho-in ◽  
Vanchai Sata ◽  
Prinya Chindaprasirt ◽  
Chai Jaturapitakkul
Keyword(s):  
Fly Ash ◽  
Geopolymer Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash
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