Assessment of Chloride Ion Penetration of Alkali Activated Low Calcium Fly Ash Based Geopolymer Concrete

2016 ◽  
Vol 692 ◽  
pp. 129-137
Author(s):  
Shravan Kumar ◽  
Kolli Ramujee
Keyword(s):  
Fly Ash ◽  
Environmental Control ◽  
Carbon Dioxide Emission ◽  
Engineering Properties ◽  
Natural Seawater ◽  
Fine Aggregate ◽  
Chloride Ingress ◽  
Geopolymer Concrete ◽  
Chloride Permeability ◽  
Test Technique

Fly ash–based geopolymer concrete (GPC) comprised of fly ash, Fine aggregate, coarse aggregate, and an alkaline solution, which is a combination of sodium hydroxide and sodium silicate, can play a significant role with respect to environmental control of greenhouse effects. The reduction in the carbon dioxide emission from cement production can contribute significantly to global temperature reduction. Current studies on geopolymer concrete are primarily focused on geopolymer technology to prepare fly ash–based geopolymer concrete and its Engineering properties determination. However, no specific publications are available with respect to the durability of geopolymer concrete in the marine environment. Corrosion of reinforcing steel due to chloride ingress ion is one of the most common environmental attacks that lead to the deterioration of concrete structures. Therefore, wherever there is a potential risk of chloride induced corrosion, the concrete should be evaluated for chloride permeability. This paper describes an durability testing program, based on Rapid chloride permeability test technique to measure the chloride permeability of in-place concrete. To investigate the durability performance of geopolymer fly ash–based concretes and OPC concretes that have been subjected to natural seawater exposure. A series of 100x50mm specimen were cut from the 100x200mm cylinders of both GPC & OPC to fit them into the test set up. The test results indicated excellent resistance of the geopolymer concrete (GPC) to chloride ingress ion with a less charge passed through them relative to ordinary Portland cement (OPC concrete)

scholarly journals Study of Proportional Variation of Geopolymer Concrete which Self Compacting Concrete

2019 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Purwanto P. ◽  
Himawan Indarto
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plant ◽  
Portland Cement ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Conventional Concrete ◽  
Basic Characteristics ◽  
Carbon Dioxide Co2 ◽  
Proportional Variation

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.

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.

scholarly journals Mechanical Behavior of Double Skinned Composite Hollow Columns using Geopolymer Concrete

2020 ◽  
Vol 8 (5) ◽  
pp. 4691-4696
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Steel Tube ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Ambient Temperatures ◽  
Granulated Blast Furnace Slag ◽  
Heat Curing ◽  
Furnace Slag

This paper comprises of the experimental study of double skinned (DSCFT) Composite hollow columns using Geopolymer concrete. The diameter-thickness (D/t) ratio and the hollowness ratio were consideredas main parameters in designing the specimens. The Geopolymer Concrete used in this project is the most promising technique. It is composed of fly-ash, fine aggregate, coarse aggregate and alkaline solution. By using large volume of ordinary Portland cement (OPC) concrete, the production of cement increases 3% annually. The production of one ton of cement directly liberates about 1 ton of CO2 and indirectly liberates 0.4 ton of CO2 to atmosphere. Among the greenhouse gases, CO2 contributes about 67% of global warming. In this respect fly ash based geopolymer mortar is highly considerable. But most of the previous works on fly ash-based geopolymers concrete reveals that hardening is due to heat curing, which is considered as a limitation for cast in situ applications at low ambient temperatures. In order to overcome this situation, replacing the Ground blast furnace slag with fly ash for various proportions to achieve geopolymer concrete suitable for curing without elevated heat. The Scope of this project is to find optimization level of Ground Granulated blast furnace slag in geopolymer concrete for curing in ambient condition and to analyze the compressive Strength of optimized GGBS based Geopolymer Concrete filled double skinned steel tube by varying the size of the steel tubes.

scholarly journals Characteristics of Blended Geopolymer Concrete Using Ultrafine Ground Granulated Blast Furnace Slag and Copper Slag

2020 ◽  
Vol 44 (6) ◽  
pp. 433-439
Author(s):  
Vijayasarathy Rathanasalam ◽  
Jayabalan Perumalsami ◽  
Karthikeyan Jayakumar
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Blast Furnace Slag ◽  
Copper Slag ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Strength Performance ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper presents the properties of blended geopolymer concrete manufactured using fly ash and ultrafine Ground Granulated Blast Furnace Slag (UFGGBFS), along with the copper slag (CPS) as replacement of fine aggregate (crushed stone sand). Various parameters considered in this study include different sodium hydroxide concentrations (10M, 12M and 14M); 0.35 as alkaline liquid to binder ratio; 2.5 as sodium silicate to sodium hydroxide ratio and cured in ambient curing condition. Further, geopolymer concrete was manufactured using fly ash as the prime source material which is replaced with UFGGBFS (0%, 5%, 10% and 15%). Copper slag has been used as replacement of fine aggregate in this study. Properties of the fresh manufactured geopolymer concrete were studied by slump test. Compressive strength of the manufactured geopolymer concrete was tested and recorded after curing for 3, 7 and 28 days. Microstructure Characterization of Geopolymer concrete specimens was done by Scanning Electron Microscope (SEM) analysis. Experimental results revealed that the addition of UFGGBFS resulted in an increased strength performance of geopolymer concrete. Also, this study demonstrated that the strength of geopolymer concrete increased with an increase in sodium hydroxide concentration. SEM results revealed that the addition of UFGGBFS resulted in a dense structure.

scholarly journals Mechanical and Microstructural Properties of Copper Slag Based Blended Geopolymer Concrete

2021 ◽  
Author(s):  
Vijayasarathy RATHANASALAM ◽  
Jayabalan PERUMALSAMI ◽  
Karthikeyan JAYAKUMAR
Keyword(s):  
Fly Ash ◽  
Mechanical Characterization ◽  
Copper Slag ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granulated Blast Furnace Slag ◽  
Mechanical And Microstructural Properties ◽  
Furnace Slag

This work presents a novel way to examine the characteristics of fly ash, copper slag (CPS) along with the addition of Ultrafine Ground Granulated Blast Furnace Slag (UFGGBFS) based Geopolymer Concrete (GPC) for various molarities (10M, 12M and 14M). In GPC, fly ash was replaced with UFGGBFS (5 %, 10 % and 15 %) and copper slag was used as fine aggregate. Mechanical Characterization such as split tensile, flexural strength, workability and water absorption were conducted . GPC characterization and microstructural behaviour was studied  by examining X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). From experimental results this study concludes that with a rise in molarity of GPC, along with incorporation of UFGGBFS, improved the performance, densification and strength of GPC.

scholarly journals Strength Assessment on Geopolymer Concrete using Ceramic Waste Powder and M-Sand

2020 ◽  
Vol 10 (1) ◽  
pp. 95-100
Keyword(s):  
Fly Ash ◽  
Ceramic Powder ◽  
Source Material ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Polypropylene Fibres ◽  
Strength Assessment ◽  
Ceramic Waste ◽  
Durability Properties ◽  
Strength And Durability

The use of abundantly available wastes such as Fly ash and ceramic powder in construction industry in the form of geopolymer concrete turns out to be the search of a very promising building material for a sustainable future[15].This study has been undertaken to investigate the strength and durability properties of geopolymer concrete by adding ceramic powder in different percentage as source material in addition with flyash[16]. All investigations are mainly focused towards geopolymer concrete mainly with flyash as source material. In this study, ceramic waste powder is added since it is also one of the major waste material as flyash. Nowadays, almost all the construction are carried out with ceramic products which results with more ceramic waste powder. Thus this work focused to utilize this waste powder into geopolymer concrete. Characteristic strength and primary durability properties are carried out by adding ceramic powder with 50%,40% and30% with fly ash. Thus this paper focuses on varying the proportions of fly ash and ceramic waste powder (50:50, 60:40, 70:30) in geopolymer concrete incorporating with polypropylene fibres in percentage of 0.5%,0.75% and 1% in volume of concrete to evaluate its strength and durability characteristics. The alkaline activator solution used is a mixture of 10 molar Sodium hydroxide and Sodium silicate in the ratio 1:3. Ambient curing condition is applied for the specimens. M-Sand is used instead of fine aggregate, since many literature reveals addition of M-Sand gains more strength in geopolymer Concrete.

scholarly journals Studies on manufactured sand effect on mechanical properties of geopolymer concrete as replacement of river sand in fine aggregate

2021 ◽  
Vol 309 ◽  
pp. 01114
Author(s):  
K. Veera Babu ◽  
T. Srinivas ◽  
Mahathi Tummala
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Material ◽  
Environmental Concerns ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
River Sand ◽  
Natural Sand ◽  
Manufactured Sand ◽  
Low Calcium

Concrete is the most adaptable, long-lasting, and dependable construction material on the planet. There are numerous environmental concerns associated with the production of OPC, and natural sand is becoming more expensive and scarce as a result of unlawful river sand dredging. The greatest replacement material for traditional concrete is geopolymer concrete with low calcium fly ash. The purpose of this paper is to investigate the mechanical properties of geopolymer concrete of grades G30 and G50, which are equivalent to M30 and M50, when river sand is substituted in various quantities with manufactured sand, such as 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. When compared to the equivalent grades of controlled concrete, geopolymer concrete improves mechanical properties such as compressive, tensile, and flexural strengths.

scholarly journals Compressive Strength of Fly-Ash-Based Geopolymer Concrete by Gene Expression Programming and Random Forest

2021 ◽  
Vol 2021 ◽  
pp. 1-17 ◽  
Author(s):  
Mohsin Ali Khan ◽  
Shazim Ali Memon ◽  
Furqan Farooq ◽  
Muhammad Faisal Javed ◽  
Fahid Aslam ◽  
...  
Keyword(s):  
Gene Expression ◽  
Compressive Strength ◽  
Fly Ash ◽  
Random Forest ◽  
Gene Expression Programming ◽  
Curing Temperature ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Soft Computing Techniques ◽  
Water Ratio

Fly ash (FA) is a residual from thermal industries that has been effectively utilized in the production of FA-based geopolymer concrete (FGPC). To avoid time-consuming and costly experimental procedures, soft computing techniques, namely, random forest regression (RFR) and gene expression programming (GEP), are used in this study to develop an empirical model for the prediction of compressive strength of FGPC. A widespread, reliable, and consistent database of compressive strength of FGPC is set up via a comprehensive literature review. The database consists of 298 compressive strength data points. The influential parameters that are considered as input variables for modelling are curing temperature T , curing time t , age of the specimen A , the molarity of NaOH solution M , percent SiO2 solids to water ratio %   S / W in sodium silicate (Na2SiO3) solution, percent volume of total aggregate (   %   A G ), fine aggregate to the total aggregate ratio F / A G , sodium oxide (Na2O) to water ratio N / W in Na2SiO3 solution, alkali or activator to the FA ratio A L / F A , Na2SiO3 to NaOH ratio N s / N o , percent plasticizer ( %   P ), and extra water added as percent FA E W % . RFR is an ensemble algorithm and gives outburst performance as compared to GEP. However, GEP proposed an empirical expression that can be used to estimate the compressive strength of FGPC. The accuracy and performance of both models are evaluated via statistical error checks, and external validation is considered. The proposed GEP equation is used for sensitivity analysis and parametric study and then compared with nonlinear and linear regression expressions.

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