Effect on Compressive Strength of Paste/Mortar/Concrete by Changing Bottom Ash Content and Activator pH

2013 ◽  
Vol 742 ◽  
pp. 304-309
Author(s):  
Woo Keun Lee ◽  
Ji Hyeon Lee
Keyword(s):  
Crystal Structure ◽  
Compressive Strength ◽  
Inorganic Material ◽  
Bottom Ash ◽  
Environmental Safety ◽  
Ash Content ◽  
Binder Phase ◽  
Geopolymer Concrete ◽  
Leaching Test ◽  
Alumino Silicate

Geopolymer is a recently developed inorganic material that can be used to produce cement. In addition to being fire and chemical resistant, geopolymer possesses excellent mechanical properties. Geopolymeric materials are synthesized by alkaline activators such as an alumino-silicate source, which forms a gel binder phase. Toxic contaminants are also immobilized in this process. In this study, inorganic paste, different contents of MBA, and several types of activators are investigated to obtain the optimum condition. In addition, the crystalloid and crystal structure of geopolymer was analyzed by XRD and FTIR. The Korea Standard Leaching Test (KSLT) was also used to evaluate the environmental safety of inorganic paste. This study showed that the compressive strength of the WG activator is approximately twice as great as the NaOH and KOH activators. At pH 13, the WG activator also showed the best pH of the activators. In addition, the compressive strength of geopolymer concrete showed about 30 MPa in this condition. Finally, it was confirmed that all harmful heavy metals in MSWI ash were stabilized.

Effect on Compressive Strength by Mixing Ratio of MSWI Melting Slag/Bottom Ash

2009 ◽  
Vol 620-622 ◽  
pp. 631-634
Author(s):  
Woo Keun Lee ◽  
Eun Zoo Park ◽  
Ji Hyeon Lee ◽  
Yeong Seok Yoo
Keyword(s):  
Crystal Structure ◽  
Heavy Metals ◽  
Compressive Strength ◽  
Bottom Ash ◽  
Environmental Safety ◽  
Resource Conservation ◽  
Leaching Test ◽  
Mixing Ratio ◽  
Mswi Bottom Ash ◽  
Melting Slag

In this work, inorganic paste was made from melting slag (MS) of MSWI ash and MSWI bottom ash (MBA) by geopolymer technique. Heavy metals such as Pb and Cu are highly contained in MBA. In the view of environmental protection and resource conservation, recycling of MSWI ash is desirable. MS and MBA were mixed to make inorganic paste. Compressive strength was measured to evaluate the characteristics of inorganic paste after the period of 1, 3 and 7day. Compressive strength of almost 90 MPa was obtained at the mixing ratio of MS : MBA = 9 : 1. And the crystalloid and crystal structure was analyzed by FTIR and XRD. Korea Standard leaching Test (KSLT) is also used to evaluate the environmental safety of inorganic paste. The leached concentration of Pb and Cu were 0.44 ppm and 0.15 ppm, respectively. According to this result, heavy metals were safety immobilized and stabilized.

Microstructure and Mechanical Properties of Ambiently-Cured Blended Coal Ash-Based Geopolymer Concrete

2016 ◽  
Vol 857 ◽  
pp. 400-404
Author(s):  
Tian Yu Xie ◽  
Togay Ozbakkaloglu
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Bottom Ash ◽  
Coal Ash ◽  
Geopolymer Concrete ◽  
Mass Ratio ◽  
Blended Coal ◽  
Microstructure And Mechanical Properties

This paper presents the results of an experimental study on the behavior of fly ash-, bottom ash-, and blended fly and bottom ash-based geopolymer concrete (GPC) cured at ambient temperature. Four bathes of GPC were manufactured to investigate the influence of the fly ash-to-bottom ash mass ratio on the microstructure, compressive strength and elastic modulus of GPC. All the results indicate that the mass ratio of fly ash-to-bottom ash significantly affects the microstructure and mechanical properties of GPCs

Development of Inorganic Binder with MSWI Ash

2008 ◽  
Vol 569 ◽  
pp. 317-320
Author(s):  
Woo Keun Lee ◽  
Eun Zoo Park ◽  
Young Do Kim ◽  
Se Gu Son ◽  
Ji Hyeon Lee
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Environmental Safety ◽  
Waste Incinerator ◽  
Geopolymer Concrete ◽  
Inorganic Binder ◽  
Active Filler ◽  
Mineral Phases ◽  
Solid Waste Incinerator

Municipal Solid Waste Incinerator (below MSWI) ash is used to develop inorganic binder for preparing geopolymer concrete in this study. Toxic substituents, such as heavy metals are de-toxificated by above-mentioned new solidity technique. Slag and coal fly ash are used as active filler to enhance compressive strength. MSWI ash was mixed with slag and coal fly ash to make geopolymer concrete. They were solidified under alkali condition and dried at 50°C and 80°C, respectively. Compressive strength was measured to evaluate the characteristics of specimens for the period of 3, 7 and 14 days. Compressive strength measurements show a maximum strength of almost 13.7 MPa after 14 days. The mineral phases of specimen were analyzed by XRD. And the morphology was analyzed by the photo of SEM. The micro-structure of inorganic binder prepared was analyzed by FTIR. Korea Standard leaching Test (KSLT) and TCLP method are used to the environmental safety of inorganic binder. Raw FA measured concentrations of Cu and Pb were 0.30 ppm and 28.31 ppm, respectively. Leaching amounts of heavy metal were noticeably reduced after the solidification of MSWI as with active filler. It is possible to de-toxificate MSWI ash by new solidity techniques. And it may be used as alternative concrete.

EVALUATION OF SHRINKAGE AND DURABILITY OF GEOPOLYMER CONCRETE USING F-CLASS COAL ASHES

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Gum Sung Ryu ◽  
Kyung Taek Koh ◽  
Gi Hong An ◽  
Jang Hwa Lee
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bottom Ash ◽  
Drying Shrinkage ◽  
Geopolymer Concrete ◽  
Cement Concrete ◽  
Fly Ash Concrete ◽  
Coal Ashes

This paper evaluates the strength, shrinkage and durability characteristics of concrete using 100% fly ash and bottom ash as binder. It is seen that the compressive strength of activated fly ash and bottom ash concrete reaches respectively 25 MPa and 30 MPa, and that the change in strength is insignificant as per the content of bottom ash powder. Moreover, the total amount of shrinkage of the activated bottom ash concrete appears to be larger than that of the activated fly ash concrete. In addition, the drying shrinkage and durable performance of the activated ash geopolymer concrete is verified to be superior to that of ordinary cement concrete.

scholarly journals Corrosion Evaluation of Geopolymer Concrete Made with Fly Ash and Bottom Ash

2021 ◽  
Vol 13 (1) ◽  
pp. 398
Author(s):  
Priyanka Morla ◽  
Rishi Gupta ◽  
Peiman Azarsa ◽  
Ashutosh Sharma
Keyword(s):  
Fly Ash ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Bottom Ash ◽  
High Rate ◽  
Geopolymer Concrete ◽  
Cell Potential ◽  
Accelerated Corrosion ◽  
Corrosion Evaluation ◽  
Alumino Silicate

Environmental pollution caused by CO2 releasing from the production of cement is a great challenge for the construction industry and has triggered exploration into more sustainable alternatives. Geopolymer Concrete (GPC) is a potential sustainable solution that does not involve the use of cement as a binder. GPC is produced by mixing the alumino-silicate source materials such as fly-ash with alkali activators such as potassium hydroxide (KOH) and potassium silicate (K2SiO3). Unlike Ordinary Portland Concrete (OPC), the characteristics of GPC depend on the precursor materials and therefore vary for different mixes. Consequently, corrosion behavior needs to be evaluated separately for individual mixes. This has narrowed the scope of existing published work on corrosion behavior of GPC. In this study, GPC and OPC specimens were prepared and exposed to accelerated corrosion exposure. Half-cell potential and linear polarization resistance were used to evaluate the corrosion rate in GPC and OPC. Under accelerated conditions, the corrosion rate of the GPC specimens was between 10 µm/year and 20 µm/year exhibiting a moderate to high rate of corrosion. Meanwhile, the corrosion rate of the OPC specimens was between 40 µm/year and 60 µm/year indicating a very high corrosion activity. It can be concluded that GPC has a higher resistance to chloride-induced corrosion; with a low corrosion rate and lower mass loss percentage, compared to OPC.

Effect of Coal Ash Properties on Compressive Strength of Bottom Ash-Based Geopolymer Concrete

2016 ◽  
Vol 857 ◽  
pp. 395-399 ◽  
Author(s):  
Tian Yu Xie ◽  
Togay Ozbakkaloglu
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Compressive Strength ◽  
Chemical Composition ◽  
Ambient Temperature ◽  
Bottom Ash ◽  
Coal Ash ◽  
Geopolymer Concrete ◽  
Strength Gain

This paper presents the results of an experimental study on the behavior of bottom ash-based geopolymer concrete (GPC) cured at ambient temperature. A total of five bathes of bottom ash-based GPC were manufactured. The influence of the particle size and chemical composition of bottom ash on the compressive strength of GPC was investigated. The results indicate that the investigated parameters significantly affect the 28-day compressive strength of bottom ash-based GPCs. It is also found that the strength gain of ambiently-cured coal ash-based GPCs continues beyond the concrete age of 28 days.

scholarly journals Effect of various parameters on the workability and strength properties of geopolymer concrete

2021 ◽  
Vol 309 ◽  
pp. 01102
Author(s):  
Nutakki Sai Ketana ◽  
V Srinivasa Reddy ◽  
M V Seshagiri Rao ◽  
S Shrihari
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Properties ◽  
Ash Content ◽  
Geopolymer Concrete ◽  
Alkaline Activator ◽  
Class C ◽  
Class F

In the present study, effect of various molarities of NaOH, various fly ash content and alkaline activator solution (AAS) / fly ash(FA) ratios on the workability of geopolymer concrete(GPC) are studied along with the effect of use of Na2SiO3/NaOH and K2SiO3/KOH as alkaline activator solutions and various fly ash contents on the compressive strength of geopolymer concrete mixes. Observations shows that both Na2SiO3/NaOH and K2SiO3/KOH gives better performance for different molar, AAS/FA and oxide ratios. Class C GPC has better performance than Class F GPC. It was found that the increase in molarity decreases workability of geopolymer concrete. Also, the workability increases with increase in fly ash (FA) content and AAS/FA ratio in geopolymer concrete. Compressive and split tensile strengths decrease with increase in fly ash content.

scholarly journals Comparative Study Involving Effect of Curing Regime on Elastic Modulus of Geopolymer Concrete

Buildings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 101 ◽  
Author(s):  
Peiman Azarsa ◽  
Rishi Gupta
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Resonant Frequency ◽  
Construction Material ◽  
Bottom Ash ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Steam Curing ◽  
Curing Regime

Geopolymer Concrete (GPC) as a cement-less construction material has attracted worldwide attention due to its lower carbon footprint. There are numerous studies reported on GPC made using different by-products including fly-ash. However, since the use of bottom-ash is comparatively limited, making potassium-based GPC using this waste can be an alternative to Portland Cement Concrete (PCC). In this study, two methods of accelerated curing were used to determine the influence of elevated temperature on the compressive strength of GPC, composed of 50% bottom-ash and 50% fly-ash. GPC specimens were cured using various temperatures including ambient, 30 °C, 45 °C, 60 °C, and 80 °C for 24 h, all followed by 28 days of ambient curing. The highest compressive strength was obtained with steam curing at a temperature of 80 °C for a duration of 24 h. It is of great significance to evaluate elastic modulus of the concrete mixture so that the short-term rigidity of structures subjected to elongation, bending, or compression can be predicted. In this study, a longitudinal Resonant Frequency Test (RFT) as a non-destructive test (NDT) was used to calculate the elastic modulus of both GPC and a comparative PCC mix. Based on the results, PCC had higher resonant frequency (by about 1000 Hz) compared to GPC. A review of empirical models for predicting GPC’s elastic modulus showed that all of the predicted elastic modulus values were lower than experimental values.

scholarly journals Bayesian Regularized Artificial Neural Network Model to Predict Strength Characteristics of Fly-Ash and Bottom-Ash Based Geopolymer Concrete

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1729
Author(s):  
Sakshi Aneja ◽  
Ashutosh Sharma ◽  
Rishi Gupta ◽  
Doo-Yeol Yoo
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Compressive Strength ◽  
Fly Ash ◽  
Bottom Ash ◽  
Geopolymer Concrete ◽  
Ann Model ◽  
Testing Procedures ◽  
Precursor Material ◽  
Artificial Neural

Geopolymer concrete (GPC) offers a potential solution for sustainable construction by utilizing waste materials. However, the production and testing procedures for GPC are quite cumbersome and expensive, which can slow down the development of mix design and the implementation of GPC. The basic characteristics of GPC depend on numerous factors such as type of precursor material, type of alkali activators and their concentration, and liquid to solid (precursor material) ratio. To optimize time and cost, Artificial Neural Network (ANN) can be a lucrative technique for exploring and predicting GPC characteristics. In this study, the compressive strength of fly-ash based GPC with bottom ash as a replacement of fine aggregates, as well as fly ash, is predicted using a machine learning-based ANN model. The data inputs are taken from the literature as well as in-house lab scale testing of GPC. The specifications of GPC specimens act as input features of the ANN model to predict compressive strength as the output, while minimizing error. Fourteen ANN models are designed which differ in backpropagation training algorithm, number of hidden layers, and neurons in each layer. The performance analysis and comparison of these models in terms of mean squared error (MSE) and coefficient of correlation (R) resulted in a Bayesian regularized ANN (BRANN) model for effective prediction of compressive strength of fly-ash and bottom-ash based geopolymer concrete.

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