Properties of modified Alberta fly ash in relation to utilization in waste management applications

1994 ◽  
Vol 21 (3) ◽  
pp. 419-426 ◽  
Author(s):  
R. C. Joshi ◽  
J. P. A. Hettiaratchi ◽  
Gopal Achari
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Hydraulic Conductivity ◽  
Waste Management ◽  
Tap Water ◽  
Curing Time ◽  
K Value ◽  
Liner Material ◽  
Water Permeation ◽  
Modified Fly Ash

This paper presents the results of a laboratory investigation on hydraulic conductivity (k, also known as coefficient of permeability), compressive strength, and contaminant leachability of self-cementitious fly ash produced by two different coal-fired thermal power plants in Alberta. Hydraulic conductivity data are presented for fly ash and lime-modified fly ash samples with tap water and brine as permeants. The tap water k values of fly ash samples are almost two orders of magnitude higher than 1 × 10−7 cm/s, the usually required k value for a landfill bottom liner material. Addition of lime to fly ash increased the unconfined compressive strength and decreased the k value. The effect was directly proportional to the curing time and the percentage of lime added to the ash. The pozzolanic reactions between lime, water, and alumino-siliceous glass in the fly ash give rise to insoluble cementitious calcium alumino silicate hydrates. These pozzolanic reaction products contribute to strength gain and decrease in k value. It is also quite possible that salt precipitation during brine permeation blocked pore spaces and resulted in decreased k value. Nonetheless, the permeabilities of lime-modified fly ash samples are significantly lower than those of fly ash samples.In general, the amount of trace elements leached from test samples during tap water permeation decreased with increasing curing time and percentage of lime in samples. Exception was lead (Pb). Leachability of Pb increased with increasing lime content and curing time. Leachate pH held constant with time, which indicates that the removal of Ca(OH)2 in pozzolanic reactions did not have a significant impact on the pore solution pH. Key words: fly ash, hydraulic conductivity, contaminants, lime, leachability, liners, waste management, compressive strength, heavy metals.

scholarly journals Hydraulic Conductivity of Compacted Lime-Softening Sludge Used as Landfill Liners

2019 ◽  
Vol 230 (12) ◽  
Author(s):  
Agnieszka Dąbska
Keyword(s):  
Hydraulic Conductivity ◽  
Moisture Content ◽  
Tap Water ◽  
Distilled Water ◽  
Landfill Liners ◽  
Water Permeation ◽  
Lime Softening ◽  
Approximate Polynomial ◽  
Hazardous Waste Landfills

AbstractThe research goal was to investigate the hydraulic conductivity of compacted lime-softening sludge as a material to be applied to landfill liners. In doing so, the effect of compaction and moulding moisture content on the sludge hydraulic conductivity was assessed. An approximate polynomial k10mean at hydraulic gradients ≥30 for degree of compaction (0.95–1.05) and moulding moisture content (28%–36%) was determined. The results of short-term tap water permeation tests revealed that all hydraulic conductivity values were less than 2.5•10–8 m/s. A lowest hydraulic conductivity of 6.5•10–9 m/s, as well as a corresponding moisture content of 31% were then established. The long-term hydraulic conductivity was measured with tap water, distilled water, NaOH and HCl solutions and municipal waste leachate. The factors of permeating liquids and permeation time significantly affected the initial hydraulic conductivity. The long-term hydraulic conductivity increased for NaOH and HCl solutions and decreased for tap and distilled water. A significant reduction of hydraulic conductivity was observed for leachate permeation. The investigated material met the requirements for the liner systems of inert landfill sites regardless of pH and the limit value for hazardous and non-hazardous waste landfills.

Effect of Curing Time and Sintering to the Properties of Geopolymer Mortars

2017 ◽  
Vol 888 ◽  
pp. 184-187
Author(s):  
Salwa Ismail ◽  
Mohammad Faizal Mohd Razali ◽  
Izwan Johari ◽  
Zainal Arifin Ahmad ◽  
Shah Rizal Kasim
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Distilled Water ◽  
Curing Time ◽  
Pore Former ◽  
X Ray ◽  
Before And After ◽  
Naoh Solution ◽  
Added Water ◽  
Alkaline Activator

In this study, the geopolymer mortars were synthesized with fly ash (FA) and silica powder as aluminosilicate sources and a combination of sodium hydroxide (NaOH) solution, sodium silicate (Na2SiO3) solution and distilled water as alkaline activator. Commercial sago was used as a pore former in the mortars. The percentage of sago used were 10, 20 and 30 wt% of FA. The amount of added water used in each mixture was 5% by weight of FA, NaOH solution and Na2SiO3 solution. The formed geopolymer mortars were cured for 1, 3 and 7 days and sintered at 1000 °C. X-ray fluoresence (XRF) shown that FA contains higher amount of silica (SiO2) and alumina (Al2O3) which is important as aluminosilicate sources. The properties of the geopolymer mortars before and after sintered at 1000 °C have been investigated. The results show that geopolymer mortars with 10% of sago content with curing time of 7 days and sintered at 1000 °C give the highest compressive strength of 13.5 MPa.

The Effect of Curing Time on the Properties of Fly Ash-Based Geopolymer Bricks

2012 ◽  
Vol 626 ◽  
pp. 937-941 ◽  
Author(s):  
W.I. Wan Mastura ◽  
H. Kamarudin ◽  
I. Khairul Nizar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
H. Mohammed
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Experimental Work ◽  
Base Material ◽  
Curing Time ◽  
Curing Conditions ◽  
Alkaline Activator

This paper reports the results of an experimental work conducted to investigate the effect of curing conditions on the properties of fly ash-based geopolymer bricks prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the curing time in the range of 1-24 hours respectively. The specimens cured for a period of 24 hours have presented the highest compressive strength for all ratio of fly ash to sand. For increasing curing time improve compressive strength and decreasing water absorption.

Lateritic Soil Treated with Waste Wood Ash As Liner in Landfill Construction

2019 ◽  
Vol 25 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Johnson R. Oluremi ◽  
Adrian O. Eberemu ◽  
Stephen T. Ijimdiya ◽  
Kolawole J. Osinubi
Keyword(s):  
Compressive Strength ◽  
Hydraulic Conductivity ◽  
Unconfined Compressive Strength ◽  
Wood Ash ◽  
Engineering Properties ◽  
Volumetric Shrinkage ◽  
Lateritic Soil ◽  
Waste Wood ◽  
K Value ◽  
British Standard

ABSTRACTInherent variability in engineering properties of lateritic soil in relation to its plasticity, permeability, strength, workability, and natural moisture content, has made it an unpredictable material for use in civil engineering works, resulting in the need for its treatment by stabilization. A lateritic soil classified as A-6(6) and CL, according to American Association of State Highway and Transportation Officials and Unified Soil Classification System of ASTM (2011), was treated with up to 10 percent waste wood ash (WWA). Compaction was carried out using four energies, namely, reduced British Standard light, British Standard light (BSL), West African Standard, and British Standard heavy, on samples, which were then examined for hydraulic conductivity, volumetric shrinkage, and unconfined compressive strength as major criteria for use as liner and for the development of acceptable zones. Specimens with 4 percent WWA content compacted with a minimum BSL energy satisfied the maximum hydraulic conductivity (k) value of 1 × 10−9 m/s, maximum volumetric shrinkage strain of 4 percent, and minimum unconfined compressive strength value of 200 kN/m2 required for use as liner in engineered landfills. The overall acceptable zone was enlarged for up to 4 percent WWA content, thereby accommodating higher moulding water content, but the minimum compactive effort required to achieve it became reduced. The beneficial treatment of lateritic soil with up to 4 percent WWA will perform satisfactorily as liner and covers in waste containment application and will minimize the pollution and environmental impact of wood waste disposal.

Effect of surface-modified fly ash on compressive strength of cement mortar

2019 ◽  
Author(s):  
Ivan Mironyuk ◽  
Tetiana Tatarchuk ◽  
Natalia Paliychuk ◽  
Iryna Heviuk ◽  
Alexander Horpynko ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Mortar ◽  
Surface Modified ◽  
Modified Fly Ash ◽  
Effect Of Surface

Experimental Research of Foam Concrete with Different Fly Ash Level

2013 ◽  
Vol 683 ◽  
pp. 400-403 ◽  
Author(s):  
Jian Wei Yue ◽  
Zan Li Sun ◽  
Yong Feng Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Chemical Method ◽  
Mechanical Test ◽  
Quantitative Relationship ◽  
Low Density ◽  
Curing Time ◽  
Foam Concrete ◽  
Comparative Tests ◽  
Relationship Of

Based on the analysis of structure formation mechanism of foam concrete prepared with chemical method, investigations by a large number of comparative tests and quantitative analysis, quantitative relationship of compressive strength and fly ash dosage on 3d, 7d and 28d foam concrete specimens are analyzed. This investigation examined effect of fly ash that mixed into admixture concerning strength of low –density foam concrete. Mechanical test were performed to measure effect of fly ash on affecting compressive. Results indicate that fly ash significantly reducing compressive strength and increasing thermal conductivity of low-density foam concrete. Moreover, experimental results show that compressive strength of each group is more and smaller with the increase of the curing time.

The effects of marble dust and fly ash on clay soil

2014 ◽  
Vol 21 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Ismail Zorluer ◽  
Suleyman Gucek
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Waste Materials ◽  
Curing Time ◽  
Freeze Thaw ◽  
Marble Dust ◽  
Increased Strength

AbstractThe use of waste materials as an additive in soil stabilization has been widespread. This is important in terms of recycling of waste materials and reducing environmental pollution. The objective of this study is to investigate the beneficial reuse of marble dust and fly ash in soil stabilization. Tests were performed on clay soil mixtures amended with marble dust and fly ash. Marble dust was used as an activator due to fly ash being inadequate for self-cementing. Unconfined compressive strength (qu), freeze-thaw, swelling, and California bearing ratio (CBR) tests were conducted to investigate the effect of marble dust and fly ash, curing time, and molding water content on geotechnical parameters. Addition of marble dust and fly ash increased unconfined compressive strength, CBR, and freeze-thaw strength, but these additives decreased swelling potential and grain loss after freeze-thaw. Increasing the curing time results in increased strength of mixtures and decreased grain loss. As a result, this study shows that the geotechnical properties of clay soil are improved with the addition of marble dust and fly ash. This is an economical and environmentally friendly solution.

Application of Sulfoaluminate Cement for Solidification/Stabilization of Fly Ash from Municipal Solid Waste Incinerators

2012 ◽  
Vol 178-181 ◽  
pp. 795-798 ◽  
Author(s):  
Qi Na Sun ◽  
Jing Miao Li ◽  
Bao Quan Huo ◽  
Ji Bing Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
High Performance ◽  
Curing Time ◽  
Leaching Toxicity ◽  
Binder Ratio ◽  
Waste Incinerators ◽  
Water Binder Ratio

Sulfoaluminate cement (SAC) was utilized for the solidification/stabilization of fly ash from municipal solid waste (MSW) incinerators. The effects of fly ash amount and water/binder ratio were investigated on compressive strength and heavy metals leaching toxicity of solidified matrices at different curing times. The results showed that prolonged curing time, lower fly ash amount and water/binder ratio enhanced the compressive strength and decreased the leaching concentrations of Zn, Pb and Cu. For 28 days cured matrices with fly ash amount 50% and water/binder ratio 0.30, the compressive strength was 32.6 MPa and the leaching concentrations of Zn, Pb and Cu were 14.73, 0.75 and 0.43 mg/L respectively. The leaching concentrations of Zn, Pb and Cu met the demand of GB 5085.3-2007. SAC is proved to be effective for MSW incinerator fly ash solidification/stabilization and high performance matrices for disposal and reuse may be achieved with further formula optimization.

scholarly journals Mechanical Properties, Microstructure, and Chloride Content of Alkali-Activated Fly Ash Paste Made with Sea Water

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1467
Author(s):  
Salman Siddique ◽  
Jeong Gook Jang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sea Water ◽  
Tap Water ◽  
Pure Water ◽  
Degree Of Polymerization ◽  
29Si Nmr ◽  
Water Based ◽  
Ft Ir ◽  
Alkali Activated

The aim of the present study is to investigate the potential of sea water as a feasible alternative to produce alkali-activated fly ash material. The alkali-activated fly ash binder was fabricated by employing conventional pure water, tap water, and sea water based alkali activating solution. The characteristics of alkali-activated materials were examined by employing compressive strength, mercury intrusion porosimetry, XRD, FT-IR, and 29Si NMR along with ion chromatography for chloride immobilization. The results provided new insights demonstrating that sea water can be effectively used to produce alkali activated fly ash material. The presence of chloride in sea water contributed to increase compressive strength, refine microstructure, and mineralogical characteristics. Furthermore, a higher degree of polymerization on the sea water-based sample was observed by FT-IR and 29Si NMR analysis. However, the higher amount of free chloride ion even after immobilization in sea water-based alkali-activated material, should be considered before application in reinforced structural elements.

STUDY ON THE INFLUENCE OF CURING TEMPERATURE ON MECHANICAL PROPERTIES OF MODIFIED FLY ASH MORTAR

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Hirotaka Matsuo ◽  
Koji Takasu ◽  
Hidehiro Koyamada ◽  
Hiroki Suyama
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Strength Properties ◽  
Curing Temperature ◽  
Static Elasticity ◽  
Flotation Technique ◽  
Accumulated Temperature ◽  
Modified Fly Ash

Using fly ash as an admixture for concrete can contribute to environmental load reduction and concrete quality improvement. However, as the quality of fly ash fluctuates depending on the ash source, quality stabilization is required. It was proved that concrete with fly ash of Japanese Industrial Standardized class II has different strength properties depending on curing temperature, but it is not obvious whether concrete with modified fly ash by flotation method has similar properties. In this study, the influence was examined on the mechanical properties when changing the curing temperature of mortar using fly ash modified by the flotation technique. The sealing curing was set to 5°C, 20°C, 40°C and 60°C. Also, after 7 days, 5°C, 40°C and 60°C, is changed to 20°C and compression strength and static elasticity coefficient were measured. The value of compressive strength and static elastic modulus showed that mortar using modified fly ash had the same characteristics as mortar with ordinary fly ash. Because it was represented by one strength compressive estimation curve regardless of the curing temperature, it became clear that compressive strength can be evaluated by roughly using accumulated temperature as an indicator.

Sign in / Sign up

Export Citation Format

Share Document