scholarly journals Utilization of Electroplating Sludge as Subgrade Backfill Materials: Mechanical and Environmental Risk Evaluation

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yu Zhang ◽  
Peixin Shi ◽  
Lijuan Chen ◽  
Qiang Tang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Content ◽  
Environmental Risk ◽  
Coal Fly Ash ◽  
Surrounding Environment ◽  
Electroplating Sludge ◽  
Backfill Materials ◽  
Standard Limit ◽  
The Impact

The electroplating sludge may pose serious threat to human health and surrounding environment without safe treatment. This paper investigated the feasibility of using electroplating sludge as subgrade backfill materials, by evaluating the mechanical properties and environmental risk of the cement-coal fly ash solidified sludge. In this study, Portland cement and coal fly ash are used to solidify/stabilize the sludge. After curing for 7, 14, and 28 days, the stabilization/solidification sludge specimens were subject to a series of mechanical, leaching, and microcosmic tests. It was found that the compressive strength increased with the increase of cement content, curing time, and the cement replacement by coal fly ash besides water content. Among these factors, the impact of water content on the compressive strength is most noticeable. It was observed that the compressive strength declined by 87.1% when the water content increased from 0% to 10%. Besides, leaching tests showed that the amount of leaching heavy metals were under the standard limit. These results demonstrated utilization of electroplating sludge in subgrade backfill material may provide an alternative for the treatment of electroplating sludge.

scholarly journals Production of ceramics from coal fly ash

2012 ◽  
Vol 18 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Biljana Angjusheva ◽  
Emilija Fidancevska ◽  
Vojo Jovanov
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Solid State ◽  
Liquid Phase ◽  
Bending Strength ◽  
Coal Fly Ash ◽  
Liquid Phase Sintering ◽  
Heating Rates ◽  
Republic Of Macedonia ◽  
The Subject

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96?0.5%, bending strength - 47.01?2 MPa, compressive strength - 170 ?5 MPa) was produced at 1100?C using the heating rate of 10?C/min.

An Investigation of Usability of Brown Coal Fly Ash for Building Materials

2013 ◽  
Vol 438-439 ◽  
pp. 30-35 ◽  
Author(s):  
Nirdosha Gamage ◽  
Sujeeva Setunge ◽  
Kasuni Liyanage
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Brown Coal ◽  
Water Contamination ◽  
Building Materials ◽  
Coal Fly Ash ◽  
Sustainable Building ◽  
Laboratory Investigations ◽  
Cold Pressed ◽  
Initial Results

The Victoria State of Australia has the second largest reserves of brown coal on earth, representing approximately 20% of the worlds reserves, and at current use, could supply Victoria with its energy for over 500 years. Its combustion, annually, yields up to 1.3 million tonnes of fly ash, which is largely use for land-fills. Disposal of fly ash in open dumps cause massive environmental problems such as ground water contamination that may create various health problems. This study focuses on the usability of brown coal fly ash to develop a sustainable building material. A series of laboratory investigations was conducted using brown coal fly ash combined with cement and aggregate to prepare cold pressed samples aiming to test their properties. Initial results indicate that compressive strength satisfies minimum standard compressive strength required for bricks or mortar.

The Effect of Substituting Rdf on the Physical and Environmental Properties of Coal Fly Ash

1988 ◽  
Vol 136 ◽  
Author(s):  
Ashaari B. Mohamad ◽  
David L. Gress
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Activity Index ◽  
Coal Fly Ash ◽  
Pozzolanic Activity ◽  
Portland Cement Concrete ◽  
Fly Ash Concrete ◽  
Refuse Derived Fuel ◽  
Cadmium And Lead

ABSTRACTRefuse-derived-fuel (RDF) consisting mainly of waste paper and plastics is a viable fuel source for the production of power. An experimental test burn partially substituting coal with RDF was undertaken by the Public Service of New Hampshire at the Merrimack Power Station.Five percent and ten percent RDF were substituted, on a BTU basis, for coal in the test bums. The chemical and physical properties of the resulting fly ash were determined. Twelve test burn days were run with 4 days of 5% RDF and 8 days of 10% RDF. Emphasis was placed on investigating the effect of the RDF fly ash on Portland cement concrete.Most of the chemical and physical properties of the coal-RDF fly ash were found to be comparable with ordinary coal fly ash except for the amount of cadmium and lead, the pozzolanic activity index and the compressive strength of fly ash concrete. Cadmium and lead were at average levels of 5.1 ppm and 102.6 ppm for the 5% RDF, and 7.8 ppm and 198.3 ppm for the 10% RDF, respectively. Although the pozzolanic activity index of coal-RDF fly ash increases over normal coal fly ash, preliminary results show that the 28-day compressive strength of concrete with direct replacement of cement and sand decreases by up to 30%. Leaching tests on crushed concrete were conducted to evaluate the environmental effect of acid rain.

Compressive strength and microstructure evolution of low calcium brown coal fly ash-based geopolymer

2019 ◽  
Vol 9 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Muhamed Khodr ◽  
David W. Law ◽  
Chamila Gunasekara ◽  
Sujeeva Setunge ◽  
Robert Brkljaca
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Brown Coal ◽  
Microstructure Evolution ◽  
Coal Fly Ash ◽  
Low Calcium

scholarly journals Modification of Ordinary Concrete Using Fly Ash from Combustion of Municipal Sewage Sludge

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 487 ◽  
Author(s):  
Gabriela Rutkowska ◽  
Piotr Wichowski ◽  
Małgorzata Franus ◽  
Michał Mendryk ◽  
Joanna Fronczyk
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sewage Sludge ◽  
Penetration Depth ◽  
Environmental Benefits ◽  
Municipal Sewage ◽  
Partial Replacement ◽  
Municipal Sewage Sludge ◽  
Water Penetration ◽  
The Impact

This article focuses on the impact of fly ash from the combustion of municipal sewage sludge (FAMSS) as a cement additive in the amounts of 5%, 10%, 15%, 20% and 25% (by mass) on selected concrete properties. In the course of the experimental work, water penetration depth and compressive strength measurements were made at various periods of curing (from 2 to 365 days). In addition, the potential impact of FAMSS on the natural environment was examined by determining the leachability of heavy metals. FAMSS-modified concretes showed small values of water penetration depth (lower than 50 mm), as well as good compressive strength (reaching minimum class C30/37 after 130 days of maturing)—similar to the compressive strength obtained for conventional concrete. In addition, the partial replacement of cement with FAMSS has environmental benefits, expressed as a reduction in CO2 emissions. In addition, study has shown that compliance with environmental requirements is associated with heavy metal leaching.

The Impact of Fly Ash after SNCR Treated with Tannin-Based Products on AAC Production

2019 ◽  
Vol 296 ◽  
pp. 173-179 ◽  
Author(s):  
Matěj Lédl ◽  
Lucie Galvánková ◽  
Rostislav Drochytka
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bulk Density ◽  
Catalytic Reduction ◽  
Xrd Analysis ◽  
Gaseous Ammonia ◽  
X Ray Diffraction ◽  
Consistency Test ◽  
Effect Of Treatment ◽  
The Impact

This paper is focused on the effect of treatment of fly ash after selective non-catalytic reduction (SNCR) with tannin on autoclaved aerated concrete (AAC) production in order to reduce or stop ammonia leakage from the fresh mixture due to its alkalinity. A pure form of tannin and a tannin-based product „Farmatan“ were used as a treatment in dosage ranging from 0,5 g – 3 g of agent per 1 kg of fly ash. Efficient dosage was determined at 2 wt.% of fly ash by the speed of an indicator change due to gaseous ammonia diluted in water. The rheological properties of fresh mixtures were observed by consistency test in Viskomat showing that Farmatan causes delay of hydration. The results of bulk density and compressive strength testing revealed that Farmatan causes an increase of bulk density and at higher amount decreases the compressive strength because of thermal crack formation due to combined effect of delayed hydration and thixotropy. Using x-ray diffraction (XRD) analysis there were no differences in phase composition observed.

Compressive strength and hydration of high-volume wet-grinded coal fly ash cementitious materials

2019 ◽  
Vol 206 ◽  
pp. 248-260 ◽  
Author(s):  
Hongbo Tan ◽  
Kangjun Nie ◽  
Xingyang He ◽  
Xiufeng Deng ◽  
Xun Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
High Volume ◽  
Cementitious Materials

Utilization of Fly Ash with Higher Loss on Ignition for Geopolymer Mortar

2015 ◽  
Vol 1129 ◽  
pp. 614-620
Author(s):  
Yasutaka Sagawa ◽  
Shu Ota ◽  
Koji Harada ◽  
Takeyoshi Nishizaki ◽  
Hiroki Goda
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Drying Shrinkage ◽  
Silicate Material ◽  
Loss On Ignition ◽  
Heat Curing ◽  
Higher Temperature ◽  
Curing Condition ◽  
Class F Fly Ash

In this study, utilization of coal fly ash with higher loss on ignition (LOI) for geopolymer mortar was investigated. The fly ash with approximately 9% of LOI was compared with Class F fly ash. Relationship between heat curing condition and strength was clarified. As the results, although compressive strength of geopolymer mortar with higher LOI was 30-50% smaller, it was available for geopolymer mortar as an alumina silicate material. The higher temperature and the longer period for initial curing, the higher strength was obtained. In order to decrease drying shrinkage, the higher temperature and the longer period for heat curing were required.

Possibilities of Using Alternative Materials as a Substitute Binder or Filler into Composites

2015 ◽  
Vol 1105 ◽  
pp. 31-35 ◽  
Author(s):  
Nadežda Števulová ◽  
Ivana Schwarzova ◽  
Viola Hospodarova ◽  
Jozef Junak ◽  
Marcela Ondova ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Steel Slag ◽  
Recycled Concrete ◽  
Partial Replacement ◽  
Alternative Materials ◽  
Activated Coal ◽  
Hemp Fibres ◽  
Lightweight Composites

This article reports on the possibilities of using selected alternative materials like hemp fibres, MgO-cement, recycled concrete, fly ash and steel slag as binder or filler replacement in composite materials in civil engineering production. These binder or filler substitutes were mixed into composites and their compressive strength was tested. The paper is divided into four parts providing the results of experiments. In first part strength parameters of lightweight composites based on natural fibres (hemp hurds) and alternative binder (MgO-cement) are presented. Compressive strength values of concrete samples with partial replacement of cement with mechanochemically activated coal fly ash are given. The third and forth part is aimed to utilization of recycled concrete and steel slag as a natural aggregate replacement in concrete mixture for purpose of structural concrete and surface roads.

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