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This study investigates how to reduce the demand on in non-renewable granite source, by replacing granite aggregate with boiler slag in the stone column. It is a fact that boiler slag is a power station waste material which causes too many environmental problems. By introducing it as a ground improvement technique, we can reduce the bulging and shear failure problems encountered on stone columns application by adding more improvement to the stone column mixture. For more enhancements to the mixture, pulverized fly ash (PFA) of Class F is added. By increasing the amount of PFA, the resistance of the stone column in term of shear and bearing capacity are increased as the PFA pozzolanic reaction begins to produce more strength during the increasing time of the curing period. Both samples of the boiler slag and PFA are taken from Sultan Salahuddin Abdul Aziz Power Station, Klang, Selangor. The materials mixed are sand, cement and water to make boiler slag aggregates -PFA (slag) mixture. This study aims to define the slag concrete performance according to the optimum configuration of the materials used in the mixture. Unconfined Compression Test (UCT) is applied to define the ideal ratio of boiler slag between 60% to 30% ratios from the total weight which applied with 2% ratio of cement from the total weight. The results of the study show that the number of boiler slags, the period of curing, and the method of curing are the most important factors in defining the slag stone column performance. Testing the samples in ordinary circumstances to entire areas can be accomplished by determining the soil properties and meeting them. The best result gained was the 40% ratio of boiler slag in a curing method that preserved the mixture moisture and temperature, which led to the optimum strength of the slag stone column.

Reducing the potential leaching of Mo and Ni from the fly ash (FA) of petroleum coke is an increasingly important issue as Asia and Europe’s demand is expected to drastically intensify as continuing urbanisation and technological innovation demands ever more electricity. In the present study, we investigated coal combustion products (CCP) from a large coal-fired power station fed with a 56:44 coal/petroleum coke blend. Results revealed that leachable concentrations of Mo and Ni from FA were in the upper non-hazardous limit and in the inert limit, respectively (2003/33/EC). Whilst common prevention measures for Mo and Ni based on the adsorption capacity of boiler slag (BS), a mixture of BS: goethite, and jarosite, were considered insufficient to reduce the potential leaching of Mo into FA leachates, a novel chemical stabilisation method based on an aggregate product of portlandite and FA immobilised both Mo and Ni such that the resulting concentrations were below the limits established in the abovementioned 2003 EC Decision. Precipitation may be responsible for the fixation of Mo and Ni in the FA: portlandite aggregates as Ca(MoO4) and NiMoO4, respectively. The findings of this novel study support the use of this aggregate to reduce FA pollutants, which will be of particular interest to nations that remain largely coal/petroleum coke-dependant., We would like to thank the staff of the power station for their support, help, and kind assistance. We wish to also thank the analytical assistance of Mercè Cabañas and Silvia Martinez (Institute of Environmental Assessment and Water Research, Spanish National Research Council, IDÆA-CSIC). The corresponding author also gratefully acknowledges IDAEA-CSIC and the Excelencia Severo Ochoa Project (CEX2018-000794-S), financed by the Ministry of Science and Innovation (MINECO, Spain) and by the Generalitat de Catalunya (AGAUR 2017 SGR41).

número del art. 5705 The potential utilization of boiler slag generated in large amounts from pulverized-coalcombustion (PCC) power plants has recently drawn much attention due to the serious problems caused to ecosystems. In order to make maximal use of the boiler slag and reduce the environmental risk it poses, this study focused on manufacturing acoustic materials using boiler slag from Chinese PCC power plants. Three promising acoustic materials were successfully manufactured from up to 80% boiler slag with different grain sizes, with the addition of 20% Portland cement. The density and compressive strength of the products were inversely proportional and the sound absorption coefficient was positively proportional to the grain size of the boiler slag. The best sound absorption coefficient was obtained in products made from the coarsest fraction of the boiler slag (MS-C). Nonetheless, all the boiler-slag-based acoustic products still demonstrated compressive strength and densities comparable to those of other acoustic materials made of Spanish bottom ash or other conventional/recycled materials. The acoustic products made from the coarsest fraction (MS-C) and medium fraction (MS-M) of the boiler slag presented good noise absorption characteristics, like those of the commercial coarse porous cement that is traditionally used as an acoustic product. Furthermore, the acoustic products were characterized by very low leach ability of potentially hazardous elements. Consequently, the manufacture of acoustic materials is a very promising application for boiler slag. On the one hand, it consumes huge amounts of boiler slag that is generated in large amounts in China. On the other hand, the acoustic products can be used extensively to produce road acoustic barriers with a high sound absorption efficiency, no significant physical or mechanical limitations and no environmental implication Foundation of China 41972179 Foundation of China 41972180 National Key R&D Program of China 2018YFF0215400 Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) CUGCJ1819

Based on the situation that the transformations of the technology which is used to reclaim the physical sensible heat of the boiler slag in some industrial captive power plants, it has been used the heat balance method and the equivalent heat drop method to calculate and analyze the thermal economic indicators before and after the transformations of the unit, and then reveal the mechanism of the impact of the boiler slag’s physical sensible heat on the thermal economy of the whole plant.

Boiler slag is a by-product that is derived from coal combustion in wet bottom boilers. Due to its low bulk density, in the compacted state it is an attractive alternative for use as structural fill material. Compared with other coal combustion by-products, the geotechnical and leaching properties of boiler slag are less known. This paper presents the results of laboratory and field investigation of boiler slag, produced in boilers where brown coal is used as fuel. Chemical and mineralogical composition, as well as mechanical properties were studied in the laboratory. A test embankment was constructed in order to identify compaction behavior and the achieved layer stiffness. A lysimeter was installed as part of the test embankment for the long-term monitoring of the quality and quantity of percolated water.

The present world energy production is heavily relying on the combustion of solid fuels like coals, peat, biomass, municipal solid waste, whereas the share of renewable fuels is anticipated to increase in the future to mitigate climate change. In Finland, peat and wood are widely used for energy production. In any case, the combustion of solid fuels results in generation of several types of thermal conversion residues, such as bottom ash, fly ash, and boiler slag. The predominant residue type is determined by the incineration technology applied, while its composition is primarily relevant to the composition of fuels combusted. An extensive research has been conducted on technical suitability of ash for multiple recycling methods. Most of attention was drawn to the recycling of the coal combustion residues, as coal is the primary solid fuel consumed globally. The recycling methods of coal residues include utilization in a cement industry, in concrete manufacturing, and mine backfilling, to name few. Biomass combustion residues were also studied to some extent with forest fertilization, road construction, and road stabilization being the predominant utilization options. Lastly, residues form municipal solid waste incineration attracted more attention recently following the growing number of waste incineration plants globally. The recycling methods of waste incineration residues are the most limited due to its hazardous nature and varying composition, and include, among others, landfill construction, road construction, mine backfilling. In the study, environmental and economic aspects of multiple recycling options of thermal conversion residues generated within a case-study area were studied. The case-study area was South-East Finland. The environmental analysis was performed using an internationally recognized methodology — life cycle assessment. Economic assessment was conducted applying a widely used methodology — cost-benefit analysis. Finally, the results of the analyses were combined to enable easier comparison of the recycling methods. The recycling methods included the use of ash in forest fertilization, road construction, road stabilization, and landfill construction. Ash landfilling was set as a baseline scenario. Quantitative data about the amounts of ash generated and its composition was obtained from companies, their environmental reports, technical reports and other previously published literature. Overall, the amount of ash in the case-study area was 101 700 t. However, the data about 58 400 t of fly ash and 35 100 t of bottom ash and boiler slag were included in the study due to lack of data about leaching of heavy metals in some cases. The recycling methods were modelled according to the scientific studies published previously. Overall, the results of the study indicated that ash utilization for fertilization and neutralization of 17 600 ha of forest was the most economically beneficial method, which resulted in the net present value increase by 58% compared to ash landfilling. Regarding the environmental impact, the use of ash in the construction of 11 km of roads was the most attractive method with decreased environmental impact of 13% compared to ash landfilling. The least preferred method was the use of ash for landfill construction since it only enabled 11% increase of net present value, while inducing additional 1% of negative impact on the environment. Therefore, a following recycling route was proposed in the study. Where possible and legally acceptable, recycle fly and bottom ash for forest fertilization, which has strictest requirements out of all studied methods. If the quality of fly ash is not suitable for forest fertilization, then it should be utilized, first, in paved road construction, second, in road stabilization. Bottom ash not suitable for forest fertilization, as well as boiler slag, should be used in landfill construction. Landfilling should only be practiced when recycling by either of the methods is not possible due to legal requirements or there is not enough demand on the market. Current demand on ash and possible changes in the future were assessed in the study. Currently, the area of forest fertilized in the case-study are is only 451 ha, whereas about 17 600 ha of forest could be fertilized with ash generated in the region. Provided that the average forest fertilizing values in Finland are higher and the area treated with fellings is about 40 000 ha, the amount of ash utilized in forest fertilization could be increased. Regarding road construction, no new projects launched by the Center of Economic Development, Transport and the Environment in the case-study area were identified. A potential application can be found in the construction of private roads. However, no centralized data about such projects is available. The use of ash in stabilization of forest roads is not expected to increased in the future with a current downwards trend in the length of forest roads built. Finally, the use of ash in landfill construction is not a promising option due to the reducing number of landfills in operation in Finland. Publishers version

In Europe hazardous wastes are classified by 14 criteria including ecotoxicity (H 14). Standardized methods originally developed for chemical and soil testing were adapted for the ecotoxicological characterization of wastes including leachate and solid phase tests. A consensus on which tests should be recommended as mandatory is still missing. Up to now, only a guidance on how to proceed with the preparation of waste materials has been standardized by CEN as EN 14735. In this study, tests including higher plants, earthworms, collembolans, microorganisms, duckweed and luminescent bacteria were selected to characterize the ecotoxicological potential of a boiler slag, a dried sewage sludge, a thin sludge and a waste petrol. In general, the instructions given in EN 14735 were suitable for all wastes used. The evaluation of the different test systems by determining the LC/EC50 or NOEC-values revealed that the collembolan reproduction and the duckweed frond numbers were the most sensitive endpoints. For a final classification and ranking of wastes the Toxicity Classification System (TCS) using EC/LC50 values seems to be appropriate.

Ternary mixtures of geopolymers obtained from the alkaline activation of metakaolin (MK), boiler slag (BS), and rice husk ash (RHA) using a solution of potassium hydroxide were mechanically, thermally, and microstructurally characterized. The geopolymer properties and final microstructures indicate that the addition of BS, despite containing large amounts of unburned material (16.36%), allows for greater densification and greater homogeneity of the geopolymeric gel, which results in greater stability in strength at long curing ages. Substitution of 30% of MK by BS results in an increase in compressive strength of up to 21% and 122% after 28 and 180 days of curing, respectively. These results demonstrate the possibility of the construction sector using geopolymers based on MK and adding BS and RHA to obtain cementitious materials with a lower environmental impact.

Na državnem cestnem omrežju Republike Slovenije je zaradi dotrajanosti omejena skupna dovoljena masa vozil na 15 premostitvenih objektih. Nastala situacija je posledica konstantnega krčenja sredstev za državne ceste v zadnjih letih, zato potrebne ter že načrtovane sanacije niso bile izvedene. Rešitev nastalih težav je izključno sanacija premostitvenih objektov. Panoga gradbeništvo je tipično storitvena dejavnost in ena izmed pokazateljev vlaganja države v infrastrukturo. Gradnja večine objektov predstavljajo obsežna in kompleksna dela. Problem se kaže v obvladovanju informacij, ki naraščajo z obsegom in številom projektov. Gradbena podjetja uporabljajo različna informacijska orodja, ki jim lajšajo načrtovanje in spremljanje procesa gradnje, tako se pojavi nepovezljivost med posameznimi orodji. Posledice tega so nepreglednost podatkov, nezmožnost avtomatiziranega prenosa podatkov ter vprašljiva kakovost in varnost posameznih podatkov. V prvem delu diplomskega dela smo na splošno predstavili problematiko premostitvenih objektov z vidika poškodb ter obrazložili pomembnost sprotnega ugotavljanja in saniranja poškodb. Na podlagi konkretnega primera (most Dolsko) smo podali opis poškodb ter predlog sanacijskih ukrepov. V nadaljevanju dela je predstavljena priprava projekta za izdelavo terminskega plana in ponudbenega tehno-ekonomskega elaborata. Priprava vsebuje: popis del, strukturo projekta (WBS) in lokacijski potek del. Pri izdelavi popisa del in strukturiranju projekta sta bili uporabljeni programski orodji Xpert in MS Project. V sodelovanju s projektantom smo izdelali lokacijski potek izvedbe del, ki služi kot pomoč pri natančnejši izdelavi terminskega plana. On the Slovenian national road network a total of 15 bridges have a weight limit restriction due to their poor condition. Their condition is a result of cuts in funding of remedial works in recent years consequently already planned remedial works were not undertaken. To remedy the problem rehabilitation of these bridges needs to be performed. Construction industry is a typical business activity and one of the key indicators of state investment in infrastructure. The construction of most structures represents the extensive and complex range of activities. The problem is reflected in the management of information, which increases with the size and number of projects. Construction companies use different IT tools that facilitate their planning and monitoring of the construction processes which may result in bad connectivity between different tools used. The result is a lack of transparency of information, inability to automate data transfer, questionable quality and safety of data. In the first part of the thesis general problems related to damage of bridges and the importance of their assessment and remediation are presented. Based on the actual case (Dolsko bridge) the description of common types of damages and a proposal for remedial action are discussed. The second part of the thesis presents the preparation of the project bill of quantities as a tender documentation. Preparation includes: project scope definition as work breakdown structure (WBS) and location of the course. Structured bill of quantities is prepared using Xpert project management tool and exported to MS Project. In collaboration with the designers, a locational course of execution of works, which serves as an aid in the production of accurate schedule was created.

Namen diplomskega dela je bil preveriti možnost uporabe stranskih produktov, ki nastanejo pri izgorevanju premoga v termoelektrarni Trbovlje za zalivne mase kanalov in geosond in jih primerjati z zalivnimi masami, ki jih je mogoče kupiti na trgu. Zalivna masa je mešanica polnila, veziva in vode, ki mora izpolnjevati zahteve glede pretočnosti, volumenske stabilnosti, trdnosti in druge, za specifične namene rabe, zahtevane lastnosti. Izvedli smo laboratorijske preiskave na različnih mešanicah stranskih produktov izgorevanja premoga ter na referenčni zalivni masi. Preizkusili smo volumensko stabilnost svežih mešanic, z reometrom smo izmerili njihovo viskoznost, opravili meritve vodovpojnosti po Enslinu, meritve adsorpcije na organsko barvilo metilen modro, po Atterbergu smo ugotavljali mejo židkosti bentonita ter merili tlačne trdnosti staranih mešanic. Ugotovili smo, da ima količina dodane vode velik vpliv na rezultate vseh preiskav, da je njen vpliv nelinearen, da bentonit kot dodatek dobro vpliva na stabilnost sveže mešanice, cement pa pripomore k povečanju trdnosti. Žlindra kot polnilo ni izkazala ugodnih rezultatov, prvič zato, ker bi jo morali odsejavati pred uporabo, drugič pa zato, ker ne veže in mešanice z žlindro ne dosegajo ustreznih trdnosti. The purpose of the thesis was to investigate the coal combustion products - CCP- from the brown coal burning thermo-power plant as a component for grouts for backfilling trenches and geo-sounds. The grout is a mixture of inert material, hydraulic binder, additives and water. It must fulfil the criteria of viscosity, volumetric stability, strength and others, for specific usage required properties, like heat permeability. The laboratory tests were performed on different mixtures of fly ash, boiler slag, cement and bentonite. Additionally, a commercial grout was investigated as a reference material. Index properties like the grain size distribution, the Enslin Neff water adsorption test, the Methylene blue test and the Atterberg limit tests were performed on dry row materials. On mixtures with water the volumetric stability and the viscosity were investigated. The compressive strength of hardened grout was measured after 28 days. The investigation shows that the water/dry mass ratio has a great influence to the mixture as well as to the hardened grout properties. Low addition of bentonite improves the stability of fresh mixture properties and the cement improves the strength of hardened fly ash grout. The boiler slag was found not to be suitable as a part of inert fill, because it is to coarse-grained and should be sieved before its use and it has not hydraulic properties.

This study focuses on the production of an alternative cementitious material with low environmental impact through the evaluation of two-coal combustion by-products. Hybrid cements based on the alkali activation of fly ash, (FA) and boiler slag (BS) blend with a proportion of Portland cement (OPC) up to 30% were produced. FA and BS contain an unburned material up to 16%. Response Surface Methodology (RSM) was used to optimize the compressive strength. BS geopolymer achieved high compressive strength (>100 MPa at 28 days) and FA geopolymer reached 30 MPa with thermal curing. The addition of OPC helped modify the curing method. In the case of hybrid based on FA (HFA), there was a significant increase in the compressive strength with levels ranging up to 65 MPa at 28 days without requiring a thermal curing. Este estudio se propuso la producción de un material cementicio alternativo de bajo impacto ambiental a partir de la evaluación de dos subproductos de la combustión del carbón. Se elaboraron dos cementos híbridos basados en la activación alcalina de una ceniza volante (FA) y una escoria de parrilla (BS) y adicionados con cemento portland (OPC) hasta en un 30%. FA y BS contienen hasta un 16% de inquemados. Para la optimización de la resistencia a la compresión se utilizó la Metodología de Superficie de Respuesta (MSR). El geopolímero BS alcanzo alta resistencia a la compresión (>100 MPa a 28 días) y el geopolímero FA reporto 30 MPa al aplicar curado térmico. La adición de OPC contribuyo a modificar el método de curado. En el caso del hibrido basado en FA (HFA), se observó un incremento significativo en la resistencia a niveles hasta de 65 MPa a 28 días sin aplicar el curado térmico.

Generating ash from a beneficial energy combustion process is a thermodynamic certainty; whether the process is burning logs in the fireplace, or burning coal in a power plant, or incinerating municipal refuse in a resource recovery facility. Rather than pose a threat to our environment and act as an impediment to siting waste-to-energy facilities, this ash is not harmful and possesses properties suitable for reuse.

One of the environmental challenges is a management of solid wastes produced by industrial activities. Among these industrial activities is energy production from power plant, which produces the waste material during the coal combustion processes. The power plant during the coal combustion processes produces the fly ash, bottom ash and boiler slag. These are solid wastes commonly referred to as coal combustion byproducts (CCBs). The coal combustion byproducts are managed in two ways: They may be disposed of in landfills or surface impoundment ponds, or they may be used in some capacity (commonly referred to as “beneficial use”). In this paper an overview of coal combustion byproducts and their physical properties are presented. The benefits of utilizing CCBs in certain application implying the utilization of CCBs in water and wastewater treatment domain are provided here as well. In fact, this paper attempts to encourage and promote the utilization of native coal combustion byproducts where the needs arise. The appropriate studies of native CCBs provide an opportunity to use these materials for supplemental needs in water environment in the future.

At present the boiler and its auxiliary equipments which are apt to form plugging powder, dust stratification, coking and slag can’t be cleaned easily. Generally, cleaning and overhaul of furnace wall is conducted when the boiler is stopped for maintenance. The abnormally operation, which is caused by dust stratification, plugging powder, coking and slag in boiler and auxiliary equipment pipelines, can lead to increasing of emissions such as CO2, SO2, NOX and heavy metal pollutants. In this paper, a intelligent cleaning machine called high temperature furnace robot is introduced, which can automatically clean plugging powder, dust stratification, coking and slag in boiler and auxiliary equipment pipelines and can conduct on-line monitoring. This robot, which is a combinative machine of robotics, sensors, automation technology, has high research and application value, thus fill a gap in the fields of cleaning robot of power plant boiler and auxiliary equipments.

Coal combustion residues which include fly ash, bottom ash and boiler slag is one of the major pollutants as these residues require large land area for their disposal. Among these residues, utilization of bottom ash in the construction industry is very low. This paper explains the use of bottom ash through pelletization. Raw bottom ash could not be pelletized as such due to its coarseness. Though pulverized bottom ash could be pelletized, the pelletization efficiency was low, and the aggregates were too weak to withstand the handling stresses. To improve the pelletization efficiency, different clay and cementitious binders were used with bottom ash. The influence of different factors and their interaction effects were studied on the duration of pelletization process and the pelletization efficiency through fractional factorial design. Addition of binders facilitated conversion of low-calcium bottom ash into aggregates. To achieve maximum pelletization efficiency, the binder content and moisture requirements vary with type of binder. Addition of Ca(OH)2 improved the (i) pelletization efficiency, (ii) reduced the duration of pelletization process from an average of 14-7min, and (iii) reduced the binder dosage for a given pelletization efficiency. For aggregate with clay binders and cementitious binder, Ca(OH)2 and binder dosage have significant effect in reducing the duration of pelletization process. � 2010 Elsevier Ltd.

Coal combustion byproducts (CCBs) arising from energy generation are the most abundant waste streams worldwide. Legislation aimed at reducing environmental pollution associated with coal combustion will continue to add to this waste stream into the future, increasing the need to develop pertinent and safe end uses for these materials. While production of CCBs continues to rise so also do the costs associated with their disposal and landfilling. This chapter presents updated information about the production of the main categories of CCB in the U.S., outlining their individual characteristics and describing their various end uses. Further, it introduces the reader to current research on potential novel end uses of CCBs, and their effect on the environment.

Approximately 90 millions tons of coal combustion by-products are produced annually in the United States, consisting of 54 million tons of fly ash (solid particles removed from smoke), 15 million tons of bottom ash, 3 million tons of boiler slag, and 20 million tons of flue gas desulfurization (FGD) material. Markets for boiler slag are well developed, but only 33% of bottom ash, 25% of fly ash and 8% of FGD residues are beneficially used.

This research assessed those properties of power plant bottom ash likely to affect its use as highway fill or pavement material, based on laboratory investigation conducted on eleven Indiana bottom ashes. Laboratory tests included: chemical analysis, mineralogical study, microscopic examination of ash particles, specific gravity, grain size distribution, sulfate soundness, Los Angeles abrasion, permeability, shear strength, moisture-density relations, degradation under compaction, compressibility, and California bearing ratio. The various test values and properties were compared to- those of representative granular soils or appropriate specifications. These comparisons provide information necessary for judging the suitability of bottom ash in Indiana highway construction. The potential environmental effects of bottom ash utilization were evaluated by performing leaching tests outlined in the EP toxicity test and an Indiana leaching method. Chemical analysis of the leachates showed that bottom ash is nonhazardous, and its effects on the quality of ground water is minimal.

A dynamic penetrometer was designed for the purpose of evaluating compaction quality in fills constructed with boiler slag. Laboratory and field calibration tests were conducted to study the effect of densification on dynamic penetration resistance. The effects of specimen preparation method (pluviation and impact compaction) and saturation on dynamic penetration resistance were investigated in the laboratory. A 0.91-m (3-ft)-deep test fill with dimensions of 6.1 m (20 ft) by 30.5 m (100 ft) was prepared in the field. Dynamic penetration resistance and in situ densities were recorded in this slag fill after 0, 2, 4, 6, 10, and 16 passes of a smooth drum vibratory roller of 5.6 tons (11.2 kips). The field-resistance values were compared with laboratory values. Charts are provided to aid both in selecting the lift thickness/number of roller passes and also for field assessment of densification in boiler slag using the dynamic penetrometer.