Aggregate impact value (AIV) of fly ash geopolymer artificial aggregate at different sodium hydroxide (NaOH) concentration

2020 ◽  
Author(s):  
Alida Abdullah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Zarina Yahya ◽  
Romisuhani Ahmad ◽  
...  
Keyword(s):  
Fly Ash ◽  
Sodium Hydroxide ◽  
Aggregate Impact Value

scholarly journals The Effects of Various Concentrations of NaOH on the Inter-Particle Gelation of a Fly Ash Geopolymer Aggregate

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1111
Author(s):  
Alida Abdullah ◽  
Kamarudin Hussin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Zarina Yahya ◽  
Wojciech Sochacki ◽  
...  
Keyword(s):  
Fly Ash ◽  
Natural Resources ◽  
Sodium Hydroxide ◽  
Microstructural Properties ◽  
Particle Volume ◽  
Synthesis Parameters ◽  
Natural Aggregates ◽  
Mechanical And Microstructural Properties ◽  
The Impact ◽  
Aggregate Impact Value

Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for samples with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3. The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited; thus, the inter-particle volume cannot be fully filled by the precipitated gels.

The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
A. Z. Mohd Ali ◽  
◽  
N. A. Jalaluddin ◽  
N. Zulkiflee ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Alkaline Solution ◽  
High Emission ◽  
New Material ◽  
Curing Regime ◽  
Solid Form ◽  
Geopolymer Paste

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. In the process, NaOH was fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared which consists of fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste were decreased. The compressive strength of the dry mix of NaOH showed 55% and the workability has dropped to 58.4%, it showed strength reduction compared to the wet mix method.

Thermal Resistance of Fly Ash Geopolymers with Alumina as Additive

2018 ◽  
Vol 281 ◽  
pp. 182-188
Author(s):  
Yong Sing Ng ◽  
Yun Ming Liew ◽  
Cheng Yong Heah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin
Keyword(s):  
Elevated Temperature ◽  
Fly Ash ◽  
Thermal Resistance ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Room Temperature ◽  
Strength Degradation ◽  
Alumina Addition ◽  
Higher Temperature ◽  
Temperature Exposure

The present work investigates the effect of alumina addition on the thermal resistance of fly ash geopolymers. Fly ash geopolymers were synthesised by mixing fly ash with activator solution (A mixture of 12M sodium hydroxide and sodium silicate) at fly ash/activator ratio of 2.5 and sodium silicate/sodium hydroxide ratio of 2.5. The alumina (0, 2 and 4 wt %) was added as an additive. The geopolymers were cured at room temperature for 24 hours and 60°C for another 24 hours. After 28 days, the geopolymers was heated to elevated temperature (200 - 1000°C). For unexposed geopolymers, the addition of 2 wt % of alumina increased the compressive strength of fly ash geopolymers while the strength decreased when the content increased to 4 wt.%. The temperature-exposed geopolymers showed enhancement of strength at 200°C regardless of the alumina content. The strength reduced at higher temperature exposure (> 200°C). Despite the strength degradation at elevated temperature, the strength attained was relatively high in the range of 13 - 45 MPa up to 1000°C which adequately for application as structural materials.

Effect of NaOH and Water Contents on Solidification of Sodium Silicate Free Geopolymer

2014 ◽  
Vol 625 ◽  
pp. 3-6 ◽  
Author(s):  
Ahmer Ali Siyal ◽  
Lukman Ismail ◽  
Zakaria Man ◽  
Khairun Azizi Azizli
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fly Ash ◽  
Portland Cement ◽  
Sodium Hydroxide ◽  
Fourier Transform Infrared Spectroscopy ◽  
Setting Times ◽  
Behavior Study ◽  
Class F Fly Ash ◽  
Water Contents

Geopolymers are fast setting binder materials possessing strength comparable with Portland cement. In this study solidification and bonding behavior of sodium hydroxide activated class F fly ash geopolymers were determined. Solidification was determined using Vicat apparatus and bonding behavior study was carried out using Fourier transform infrared spectroscopy (FTIR). The decrease in solidification time from 105 minutes to 90 minutes was observed when Na/Al ratio increased from 1 to 1.4. By changing liquid to solid (L/S) ratio from 0.154 to 0.231 initial and final setting times found to increase. FTIR results showed main peaks at 1000 cm-1and 1432 cm-1due to asymmetric stretching of Al-O/ Si-O bonds.

scholarly journals Characterization and Performance of Mechanical Properties of GGBS Based Geo Polymer Mortars

2019 ◽  
Vol 8 (4) ◽  
pp. 8336-8342
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Construction Industry ◽  
Research Paper ◽  
Setting Times ◽  
And Performance ◽  
Creep And Shrinkage

From decades it has been recognized that Geopolymer will considerably replace the role of cement in the construction industry. In general, Geopolymer exhibits the property of the peak compressive strength, minimal creep and shrinkage. In this current research paper, Geopolymer mortar is prepared by using GGBS and Fly ash. The mix proportions are of (100-60)%GGBS with Fly ash by 10% replacement. The alkali activators Na0H and Na2Sio3 are used in the study for two different molarities of 4&8. The ratio to Sodium silicates to sodium hydroxide is maintained from 1.5, 2, 2.5 & 3 were used. Mortars are prepared and studied the effect of molarities of alkali activators in their setting times and strengths

scholarly journals Non-Destructive Test on Granite Powder Concrete

2021 ◽  
Vol 9 (4) ◽  
pp. 357-360
Keyword(s):  
Fly Ash ◽  
Sodium Hydroxide ◽  
Silica Fume ◽  
Ambient Air ◽  
Rebound Hammer ◽  
Primary Parameter ◽  
Exploratory Investigation ◽  
Granite Powder ◽  
Test Outcomes ◽  
Non Destructive

This paper presents a definite exploratory investigation on penetrability qualities of granite powder (GP) concrete. The primary parameter researched in this investigation was M30 and M60 grades concrete with substitution of sand by GP of 0, 25,50 and 100 and concrete as fractional supplanting with super plasticiser, fly ash, slag and silica fume. The antacid arrangement utilized for present examination is the mix of sodium hydroxide and sodium silicate arrangement. The test example was 50 mm (thick) x 100 mm (diameter) cylinder shapes heat-relieved at 60°C in an oven. The variety was concentrated on the examples exposed to ambient air just as oven heat relieving. non-destructive tests on cylinders with the help of rebound hammer for a time of 28, 56, 90, 180 and 365 days. The test outcomes show that the substitution of rock and incomplete substitution of admixtures display better execution

Physical, Mechanical and Micro-Structural Properties of F Type Fly-Ash Based Geopolymeric Bricks Produced by Pressure Forming Process

2010 ◽  
Vol 69 ◽  
pp. 69-74 ◽  
Author(s):  
Ömer Arıöz ◽  
Kadir Kilinç ◽  
Mustafa Tuncan ◽  
Ahmet Tuncan ◽  
Taner Kavas
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Heat Treatment Temperature ◽  
Treatment Duration ◽  
Treatment Temperature ◽  
Alumino Silicate ◽  
Heat Treatment Duration

Geopolymer is a new class of three-dimensionally networked amorphous to semi-crystalline alumino-silicate materials, and first developed by Professor Joseph Davidovits in 1978. Geopolymers can be synthesized by mixing alumino–silicate reactive materials such as kaolin, metakaolin or pozzolans in strong alkaline solutions such as NaOH and KOH and then cured at room temperature. Heat treatment applied at higher temperatures may give better results. Depending on the mixture, the optimum temperature and duration vary 40-100 °C and 2-72 hours, respectively. The properties of geopolymeric paste depend on type of source material (fly ash, metakaolin, kaolin), type of activator (sodium silicate-sodium hydroxide, sodium silicate-potassium hydroxide), amount of activator, heat treatment temperature, and heat treatment duration. In this experimental investigation, geopolymeric bricks were produced by using F-type fly ash, sodium silicate, and sodium hydroxide solution. The bricks were treated at various temperatures for different hours. The compressive strength and density of F-type fly ash based geopolymeric bricks were determined at the ages of 7, 28 and 90 days. Test results have revealed that the compressive strength values of F-type fly ash based geobricks ranged between 5 and 60 MPa. It has been found that the effect of heat treatment temperature and heat treatment duration on the density of F-type fly ash based geobricks was not significant. It should be noted that the spherical particle size increased as the heat treatment temperature increased in the microstructure of F-type fly ash based geobricks treated in oven at the temperature of 60 °C for 24 hours.

scholarly journals A Machine Learning-Assisted Numerical Predictor for Compressive Strength of Geopolymer Concrete Based on Experimental Data and Sensitivity Analysis

2020 ◽  
Vol 10 (21) ◽  
pp. 7726
Author(s):  
An Thao Huynh ◽  
Quang Dang Nguyen ◽  
Qui Lieu Xuan ◽  
Bryan Magee ◽  
TaeChoong Chung ◽  
...  
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Sensitivity Analysis ◽  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Engineering Properties ◽  
Percentage Error ◽  
Geopolymer Concrete ◽  
Statistical Measures

Geopolymer concrete offers a favourable alternative to conventional Portland concrete due to its reduced embodied carbon dioxide (CO2) content. Engineering properties of geopolymer concrete, such as compressive strength, are commonly characterised based on experimental practices requiring large volumes of raw materials, time for sample preparation, and costly equipment. To help address this inefficiency, this study proposes machine learning-assisted numerical methods to predict compressive strength of fly ash-based geopolymer (FAGP) concrete. Methods assessed included artificial neural network (ANN), deep neural network (DNN), and deep residual network (ResNet), based on experimentally collected data. Performance of the proposed approaches were evaluated using various statistical measures including R-squared (R2), root mean square error (RMSE), and mean absolute percentage error (MAPE). Sensitivity analysis was carried out to identify effects of the following six input variables on the compressive strength of FAGP concrete: sodium hydroxide/sodium silicate ratio, fly ash/aggregate ratio, alkali activator/fly ash ratio, concentration of sodium hydroxide, curing time, and temperature. Fly ash/aggregate ratio was found to significantly affect compressive strength of FAGP concrete. Results obtained indicate that the proposed approaches offer reliable methods for FAGP design and optimisation. Of note was ResNet, which demonstrated the highest R2 and lowest RMSE and MAPE values.

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