scholarly journals Freeze-Thaw Performance Characterization and Leachability of Potassium-Based Geopolymer Concrete

2020 ◽  
Vol 4 (2) ◽  
pp. 45 ◽  
Author(s):  
Peiman Azarsa ◽  
Rishi Gupta
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Natural Resources ◽  
Co2 Emission ◽  
Bottom Ash ◽  
Construction Materials ◽  
Standard Test ◽  
Test Method ◽  
Geopolymer Concrete ◽  
Freeze Thaw

It is well known that concrete is one of the most widely used construction materials in the world, and cement as its key constituent is partly responsible for global Carbon Dioxide (CO2) emission. Due to these reasons, high strength concrete with lower CO2 emission, and concrete with lower reliance on natural resources is increasingly popular. Geopolymer Concrete (GPC), due to its capability to minimize the consumption of natural resources, has attracted the attention of researchers. In cold regions, frost action is one of the primary GPC deterioration mechanisms requiring huge expenditures for repair and maintenance. In this regard, two types of GPC (fly-ash based GPC and bottom-ash based GPC) were exposed to the harsh freeze-thaw conditions using a standard test method. The dynamic elastic modulus of both types of GPC was determined using a Non-Destructive Test (NDT) method called Resonant Frequency Test (RFT). The results of RFT after exposing to 300 freeze-thaw cycles showed that bottom-ash based GPC has better freeze-thaw resistance than fly-ash based GPC. Moreover, in this study, the leachability of bottom-ash based GPC was also investigated to trace the heavy metals (including Si, Al, Na, Cr, Cu, Hg) using Toxicity Characteristic Leaching Procedure (TCLP) test. The results of the TCLP test showed that all of the heavy metals could be effectively immobilized into the geopolymer paste.

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

Manufacture of Non-Toxic Lava from Recovery of the Incineration Ash by Plasma Fusing Technology

2011 ◽  
Vol 194-196 ◽  
pp. 2365-2375
Author(s):  
Jai Houng Leu ◽  
Li Fong Wu ◽  
Ay Su
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Dissolution Rate ◽  
Bottom Ash ◽  
Reduction Ratio ◽  
National Standards ◽  
Toxic Heavy Metals ◽  
Mixture Ratio ◽  
Sustainable Operation ◽  
The Stability

This research investigated and explored the overall technical and legal suggestions on mixed ash (bottom ash + fly ash) from the first BOT(built-operation then transfer) incineration plant in south Taoyuan of Taiwan, with the hope of serving as the reference for treating ash from urban refuse incinerator and making sustainable operation management policies in Taiwan. Both bottom ash and fly ash contain high-content harmful metals like lead, chrome, and cadmium, with the lead content exceeding standard value. Plasma fusing technology may effectively settle toxic heavy metals and reduce their dissolution rate. The results show that the increase in percentage of bottom ash could maintain post-fusing strength and produce solidification effect, but this reduced the stability of toxic heavy metals and raised their dissolution rate. Suitable mixture ratio of bottom ash and fly ash was 2:1, volume reduction ratio 0.349, and weight reduction ratio 0.4936. The mixture was fulvous and dense with gloss and adequate strength. The dissolution test of lava products complied with national standards, and they might be used for recycling aggregates and solidifying cement.

Alternative Concrete – Geopolymer Concrete

2021 ◽  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Industry ◽  
Building Material ◽  
Construction Materials ◽  
Raw Material ◽  
Geopolymer Concrete ◽  
Sustainable Solutions ◽  
New Construction ◽  
Alkali Activated

Concrete is the most versatile, durable and reliable material and is the most used building material. It requires large amounts of Portland cement which has environmental problems associated with its production. Hence, an alternative concrete – geopolymer concrete is needed. The general aim of this book is to make significant contributions in understanding and deciphering the mechanisms of the realization of the alkali-activated fly ash-based geopolymer concrete and, at the same time, to present the main characteristics of the materials, components, as well as the influence that they have on the performance of the mechanical properties of the concrete. The book deals with in-depth research of the potential recovery of fly ash and using it as a raw material for the development of new construction materials, offering sustainable solutions to the construction industry.

Durability of concrete containing chloride-based accelerating admixtures

1990 ◽  
Vol 17 (1) ◽  
pp. 102-112
Author(s):  
T. Rezansoff ◽  
D. Stott
Keyword(s):  
Calcium Chloride ◽  
Dynamic Modulus ◽  
Linseed Oil ◽  
Standard Test ◽  
Test Method ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Cement Ratio ◽  
Freeze Thaw ◽  
Water To Cement Ratio

The influence of CaCl2 or a chloride-based accelerating admixture on the freeze–thaw resistance of concrete was evaluated. Three air entrained mix designs were investigated using ASTM C666-84, Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing. All mix designs were similar, using cement contents of 340–357 kg/m3 of concrete, except for the addition of either 2% calcium chloride or 2% High Early Pozzolith, while no accelerating admixture was added to the control mix. The entire test program was repeated four times with water-to-cement ratio of 0.46 and three times with the ratio of 0.43. For the Pozzolith-accelerated concrete, half the samples were coated with boiled linseed oil in all seven series. For the control (unaccelerated) concrete, half the samples were coated with boiled linseed oil in one series for each water-to-cement ratio. Performance was monitored using the dynamic modulus of elasticity as obtained from transverse resonant frequency measurements. Weight loss of the specimens was also measured. Only the control samples (no accelerators) showed sufficient durability to satisfy the standard of maintaining at least 60% of the original dynamic modulus after 300 cycles of alternate freezing and thawing. Sealing with linseed oil showed inconsistent improvement in the durability in the various test series when defined in terms of the dynamic modulus; however, weight losses were the lowest of all categories and surface scaling was minimal. Key words: concrete, durability, freeze–thaw testing, calcium chloride, admixtures, sealants, air void system.

scholarly journals Stabilization of Municipal Solid Waste Fly Ash, Obtained by Co-Combustion with Sewage Sludge, Mixed with Bottom Ash Derived by the Same Plant

2020 ◽  
Vol 10 (17) ◽  
pp. 6075
Author(s):  
Ahmad Assi ◽  
Fabjola Bilo ◽  
Alessandra Zanoletti ◽  
Laura Borgese ◽  
Laura Eleonora Depero ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Sewage Sludge ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Coal Fly Ash ◽  
Bottom Ash ◽  
Solid Material ◽  
Flue Gas Desulfurization ◽  
Stabilization Method

This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue gas desulfurization residues and coal fly ash. Leaching tests were performed on stabilized samples, aged in a laboratory at different times. The results reveal the reduction of the concentrations of heavy metals, particularly Zn and Pb about two orders of magnitude lower with respect to fly ash. The immobilization of heavy metals on the solid material mainly depends on three factors—the amount of used ash, the concentrations of Zn and Pb in as-received fly ash and the pH of the solution of the final materials. The inert powder, obtained after the stabilization, is a new eco-material, that is promising to be used as filler in new sustainable composite materials.

Freeze-thaw resistance of Class F fly ash-based geopolymer concrete

2019 ◽  
Vol 222 ◽  
pp. 474-483 ◽  
Author(s):  
Renda Zhao ◽  
Yuan Yuan ◽  
Zhengqing Cheng ◽  
Tian Wen ◽  
Jian Li ◽  
...  
Keyword(s):  
Fly Ash ◽  
Geopolymer Concrete ◽  
Freeze Thaw ◽  
Class F Fly Ash ◽  
Class F

Feasibility of Reutilizing Municipal Solid Waste Incineration Residues as Construction Materials

2012 ◽  
Vol 164 ◽  
pp. 289-292 ◽  
Author(s):  
Rui Jing Zhang ◽  
Yan Jun Hu
Keyword(s):  
Heavy Metals ◽  
Solid Waste ◽  
Bottom Ash ◽  
Construction Materials ◽  
Fine Fraction ◽  
Road Construction ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Road Base ◽  
Incineration Residues

Abstract: The presented study mainly focused on investigating detailed engineering properties of municipal solid waste incineration residues as road construction materials with different application classes. Also, the leachability of heavy metals and salts in the residues as a function of the ratio of liquid and solid was tested. The Chinese specifications about road construction materials were employed to evaluate the application capacity of the waste incineration residues. The obtained results indicate that bottom ash basically complies with the technical requirements for road base and sub-base materials with exception of the low compataclity and high organic content of the fine fraction. The toxicity test showed that bottom ash can satisfy the limit values of heavy metals and salts that was established by Chinese specification for hazard solid waste. For the application of the ash in road base, it should be mixed with other materials to improve the compataclity. Pretreatment of fine fraction of bottom ash to remove organic matter is necessary.

scholarly journals Leachability of Self-Compacting Concrete (SCC) Incorporated With Fly Ash and Bottom Ash by Using Static Leaching Procedure (SLT)

2015 ◽  
Vol 773-774 ◽  
pp. 1261-1265 ◽  
Author(s):  
Aeslina Abdul Kadir ◽  
Mohd Ikhmal Haqeem Hassan ◽  
Syed Khairul Hafizi bin Syed Mohamad
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Power Plants ◽  
Bottom Ash ◽  
Coal Ash ◽  
Negative Effects ◽  
Self Compacting Concrete ◽  
Aas Method ◽  
Set Up ◽  
Synthetic Acid

The growing demand for electricity resulted in the construction of many coal fired power plants. The increment of the consumption of coal by power plants lead up to production of coal ash. Coal ash contains a range of toxic elements that may have negative effects to human and environmental health. Fly ash (FA) and bottom ash (BA) are the solid residues and mostly arise from coal combustion that being disposed in large quantities every year. The focus of the study is to determine the leachability of Self-Compacting Concrete (SCC) incorporated with FA and BA by using Static Leachate Test (SLT) method. In this study, FA and BA were collected from Kapar Energy Ventures Coal Power Plant in Selangor. The characteristics of Ordinary Portland cement (OPC), FA and BA were determined by using X-Ray Fluorescent (XRF) technique. The different percentages of FA (replace cement) and BA (replace sand) which is 0%, 10%, 20% and 30% were incorporated respectively into SCC. Ten reactors were set up for the leachability test for each solid specimen by using SLT method. The concentrations of leachate samples were analyzed for selected heavy metals content by using Atomic Absorption Spectroscopy (AAS) method. After 40 days conducting the test, the concentrations of selected heavy metals (As, Mn, Cu, Cr, Zn, Ni, Fe and Pb) in the synthetic acid rain leachates from the SCC specimens were significantly lower than the limit specified by the USEPA and EPAV. Therefore, incorporating of FA and BA up to 30% into SCC is potentially feasible.

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