scholarly journals Stabilization of Peat Soil Using Fly Ash, Bottom Ash and Portland Cement: Soil Improvement and Coal Ash Waste Reduction Approach

Author(s):  
Ali Hauashdh ◽  
Radin Maya Saphira Radin Mohamed ◽  
Junaidah Jailani ◽  
Junita Abd Rahman
2021 ◽  
Vol 7 (1) ◽  
pp. 98-106
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán

Coal fly ash (CFA), coal bottom ash (CBA) are residues produced in thermo-electrical power stations as result of the coal combustion in the same boiler. Therefore, some characteristics of the coal fly ash (CFA) are comparable with those of the coal bottom ash (CBA). Nevertheless, coal bottom ash size is larger than coal fly ash one. Consequently, it was found that it is necessary to grind the coal bottom ash (CBA) to reach a similar size to that one of the CFA. The objective of this paper is to evaluate the performance of Portland cement mortars made with coal fly ash (CFA), coal bottom ash (CBA) or mixes (CFA+CBA), against sulphate attack. The methodology is based on the expansion of slender bars submerged in a sodium sulphate solution (5%) according to the ASTM C-1012/C1012-13 standard. It has been found that mortars elaborated with CEM I 42.5 N (without ashes) presented the largest expansion (0.09%) after a testing period of 330 days. Mortars made with CEM II/A-V exhibited lower expansion (0.03%). Summing up, it can be established that mortar expansion decreases when the coal ash amount increases, independently of the type of coal ash employed. The novelty of this paper relies on the comparison between the performances of Portland cement mortars made with coal fly ash (CFA) or coal bottom ash (CBA) exposed to external sulphate attack. Doi: 10.28991/cej-2021-03091640 Full Text: PDF


J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 223-232
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán

Ground coal bottom ash is considered a novel material when used in common cement production as a blended cement. This new application must be evaluated by means of the study of its pozzolanic properties. Coal bottom ash, in some countries, is being used as a replacement for natural sand, but in some others, it is disposed of in a landfill, leading thus to environmental problems. The pozzolanic properties of ground coal bottom ash and coal fly ash cements were investigated in order to assess their pozzolanic performance. Proportions of coal fly ash and ground coal bottom ash in the mixes were 100:0, 90:10, 80:20, 50:50, 0:100. Next, multicomponent cements were formulated using 10%, 25% or 35% of ashes. In general, the pozzolanic performance of the ground coal bottom ash is quite similar to that of the coal fly ash. As expected, the pozzolanic reaction of both of them proceeds slowly at early ages, but the reaction rate increases over time. Ground coal bottom ash is a promising novel material with pozzolanic properties which are comparable to that of coal fly ashes. Then, coal bottom ash subjected to an adequate mechanical grinding is suitable to be used to produce common coal-ash cements.


2016 ◽  
Vol 857 ◽  
pp. 400-404
Author(s):  
Tian Yu Xie ◽  
Togay Ozbakkaloglu

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


2013 ◽  
Vol 465-466 ◽  
pp. 937-943
Author(s):  
Abd Rahim bin Hj. Awang ◽  
Wan Hilmi bin Wan Mansor ◽  
Ahmad Yusri Bin Mohamad

In Malaysia, coal has been used as a raw material to generate electricity since 1988. In the past, most of the wastage of coal burning especially the bottom ash was not managed properly as it was dumped in the waste pond and accumulated drastically. This research has been conducted to explore the physical characteristic and geotechnical properties of fly ash-bottom ash (FA-BA) mixtures that consist of 30% FA, 50% FA, 70% FA and 90% FA by weight. The physical characteristics, that include the specific gravity, particle size distribution and compaction, were tested for each mixture without any curing. However, the geotechnical properties of the mixtures that include the permeability and shear strength had been studied at various curing periods (0, 14 and 28 days) to review the effect of time on the geotechnical properties of the mixtures. The results show that mixtures with higher FA composition have lower value of specific gravity, well-graded, and need less moisture to be compacted efficiently compared to those mixtures with lower FA composition. The results also show that mixtures with higher FA composition have less drainage characteristics but can be improved by prolonging the curing period. The maximum shear strength was obtained at mixture with 50%FA and the value increased with curing periods. The friction angle obtained ranged from 270to 370. It is also found that the mixtures with lower FA composition are more compressible compared to the mixtures with higher FA composition. The results obtained could be used by others to determine the suitability of different FA-BA mixtures for various usage in Geotechnical Engineering work such as for soil improvement work in weak soils or as backfill materials in embankment construction.


2011 ◽  
Vol 378-379 ◽  
pp. 389-392
Author(s):  
Tomáš Daněk ◽  
Jan Thomas ◽  
Jan Jelínek ◽  
Jiří Mališ

The aim of this study was to quantify the properties of sludge from iron and steel industry with high content of heavy metals, which has been solidified/stabilised by coal fly ash and Portland cement. The mixtures of sludge and coal fly ash and/or cement after of curing were used for tests. The porosity and permeability characteristics of solidified sludge were examined. To understand the behaviour of mixtures in the long term, the prepared mixtures were tested after 14, 28, 56 and 120 days.


2015 ◽  
Vol 773-774 ◽  
pp. 1261-1265 ◽  
Author(s):  
Aeslina Abdul Kadir ◽  
Mohd Ikhmal Haqeem Hassan ◽  
Syed Khairul Hafizi bin Syed Mohamad

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Atikah Rahmi ◽  
Siti Noor Linda Taib ◽  
Fauzan Sahdi

Natural peat is considered incapable of supporting built structure due to its poor engineering properties. Chemical stabilization is one of the peat soil improvement methods which has been studied by many researchers. This study describes an investigation of water additive (W/A) ratio application on cement-stabilized peat strength. Peat soil at different moisture contents, which are 1210%, 803%, and 380%, were stabilized with cement by W/A ratio of 2.0, 2.5, 3.0, 3.5, and 4.0. Unconfined compressive strength (UCS) test was conducted after the specimens were being air-cured for 28 and 56 days. The result shows that there is an increase of UCS value as the decrease of W/A ratio (the increase of cement dosage) and the increase of curing time and peat moisture content. The higher strength found in the specimen with higher moisture content, compared to the lower one at the same W/A ratio, shows that the mix design of cement-stabilized peat using W/A ratio should have differed under different peat natural moisture contents. From the result, it is also found that cement hydrolysis reaction occurred despite the presence of humic acid in the peat soil, which by many studies is assumed will hinder the cement-soil reaction.


1988 ◽  
Vol 25 (4) ◽  
pp. 694-704 ◽  
Author(s):  
P. S. Toth ◽  
H. T. Chan ◽  
C. B. Cragg

Fly ash and bottom ash obtained from coal-fired electric power generating stations can be used as alternatives to natural materials for the construction of structural fills. The engineering properties of coal ash pertinent to its use in structural fills are discussed. Four case studies of coal ash structural fills are presented. The performance of these fills was monitored during and after construction. These cases demonstrate that the physical behavior of fly ash is similar to that of silt and that it can be handled with similar methods. Groundwater monitoring data from existing fly ash fills are presented to show the impact that ash leachate migrating into the groundwater regime has on water quality. Results of long-term corrosion studies are presented to show that metals buried in ash, used in such structures as culverts, cable ducts, guard rails and streetlights, are not adversely affected. Ash leachate was found not to be detrimental to good-quality concrete structures. Key words: fly ash, fill, compaction, leachate, corrosion, concrete.


2013 ◽  
Vol 594-595 ◽  
pp. 465-470 ◽  
Author(s):  
Aeslina binti Abdul Kadir ◽  
Mohd Ikhmal Haqeem Hassan

Over the centuries, concrete is commonly been used in construction world due to its properties. From the conventional concrete until the concrete that has been diversify with innovations, the usefulness is still the same, which is as building materials. One of the innovations called Self-Compaction Concrete (SCC). SCC is a type of concrete that does not require any mechanical compaction at all. This type of concrete will leveled and compacted under its self-weight. Such concrete will accelerate the placement, reduce the labor requirements needed for consolidation, finishing and eliminate environmental pollution. In terms of sustainability, previous researchers have recycled so many waste in SCC for example coal ash, silica fume, hydraulic lime, rice husk ash and fine limestone powder. Recently, recycling fly ash and bottom ash in SCC has grasped the attention of researchers as it demonstrated promising results. Furthermore, previous investigations already confirmed the potential of fly ash and bottom ash in replacing aggregates in SCC represents a better option than landfill and at the same time will decrease pollution problem especially in coal combustion area. This paper reviews the fly ash and bottom ash replacement in SCC.


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