scholarly journals Utilization of Industrial Byproducts for Enhancing the Properties of Cement Mortars at Elevated Temperatures

2021 ◽  
Vol 13 (21) ◽  
pp. 12104
Author(s):  
Vasiliki Pachta ◽  
Eleftherios K. Anastasiou

The research on industrial byproducts, such as slags and fly ash, was intense during the last decades in the building sector. Apart from the environmental benefits coming from their exploitation, their application may lead to the production of cost effective and durable building materials, such as mortars and concrete. The impact of industrial byproducts on the resistance of materials to fire and elevated temperatures was assessed by many scientists, however, it is still an open field of research. In this study, locally available byproducts were investigated, including High Calcium Fly Ash (HCFA), coming from lignite-fired power plants, as well as Ladle Furnace Steel (LFS) slag and Electric Arc Furnace (EAF) slag aggregates, originating from the steel making industry. Six mortar compositions were manufactured with substitution of Ordinary Portland Cement (OPC) with HCFA and LFS slag (20% w/w) and of natural aggregates with EAF slag (50% w/w). At the age of 7, 28, and 90 days, the physico-mechanical properties of the specimens were recorded, while they were further exposed at elevated temperatures, concerning 200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C. After each exposure, their physico-mechanical and microstructure characteristics were identified. From the evaluation of the results, it was asserted that HCFA and EAF slag aggregates enhanced the overall performance of mortars, especially up to 600 °C. LFS was beneficial only in combination with EAF slag aggregates.

2021 ◽  
Vol 13 (19) ◽  
pp. 10544
Author(s):  
Paolo Bragolusi ◽  
Chiara D’Alpaos

PV energy generates economic and environmental benefits (e.g., energy cost-saving, GHG emissions reduction, etc.), which can be capitalized into market prices. There is, therefore, growing interest in assessing the value that PV systems add to solar homes (i.e., homes equipped with PV production plants) market prices. Although the number of solar homes has experienced rapid growth in Europe and Italy, literature investigating the impact of PV power plants on home values is still very limited. This paper aims to fill this gap. We implement a Discrete Choice Experiment (DCE) approach to estimate individuals’ WTP for different typologies of domestic PV plants, which vary in technical characteristics. Our findings show that homebuyers are willing to pay a price premium for solar homes, ranging from some 3% to some 15%, depending on PV panels’ characteristics. These results can provide a wealth of recommendations to different interested parties such as homeowners, homebuyers, realtors, and governments, seeking knowledge on the capitalization effect of residential PV plants on the housing market to implement cost-effective investment strategies or design optimal policy incentives.


Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.


1999 ◽  
Vol 09 (03n04) ◽  
pp. 417-422 ◽  
Author(s):  
V. VIJAYAN ◽  
S. N. BEHERA

Fly ash is a major component of solid material generated by the coal-fired thermal power plants. In India the total amount of fly ash produced per annum is around 100 million tonnes. Fly ash has a great potential for utilization in making industrial products such as cement, bricks as well as building materials, besides being used as a soil conditioner and a provider of micro nutrients in agriculture. However, given the large amount of fly ash that accumulate at thermal power plants, their possible reuse and dispersion and mobilization into the environment of the various elements depend on climate, soils, indigenous vegetation and agriculture practices. Fly ash use in agriculture improved various physico-chemical properties of soil, particularly the water holding capacity, porosity and available plant nutrients. However it is generally apprehended that the application of large quantity of fly ash in fields may affect the plant growth and soil texture. Hence there is a need to characterize trace elements of fly ash. The results of trace element analysis of fly ash and pond ash samples collected from major thermal power plants of India by Particle Induced X-ray Emission (PIXE) have been discussed.


2020 ◽  
Vol 21 ◽  
pp. 24-30
Author(s):  
Suha Ismail Ahmed Ali ◽  
Éva Lublóy

The construction of radiation shielding buildings still developed. Application of ionizing radiations became necessary for different reasons, like electricity generation, industry, medical (therapy treatment), agriculture, and scientific research. Different countries all over the world moving toward energy saving, besides growing the demand for using radiation in several aspects. Nuclear power plants, healthcare buildings, industrial buildings, and aerospace are the main neutrons and gamma shielding buildings. Special design and building materials are required to enhance safety and reduce the risk of radiation emission. Radiation shielding, strength, fire resistance, and durability are the most important properties, cost-effective and environmentally friendly are coming next. Heavy-weight concrete (HWC) is used widely in neutron shielding materials due to its cost-effectiveness and worthy physical and mechanical properties. This paper aims to give an overview of nuclear buildings, their application, and behaviour under different radiations. Also to review the heavy-weight concrete and heavy aggregate and their important role in developing the neutrons shielding materials. Conclusions showed there are still some gaps in improving the heavy-weight concrete (HWC) properties.


2019 ◽  
Vol 296 ◽  
pp. 149-154
Author(s):  
Radomír Sokolář ◽  
Martin Nguyen

Fluid fuel combustion technology in coal-fired power plants is very popular in the Czech Republic, resulting in a relatively high production of a specific by-product - fluidized fly ash (class C according to ASTM definition), which differs from the classical high-temperature fly ash in mineralogical composition with a high sulphur content of anhydrite CaSO4. Fluidized ash is not yet used in the production of fired building materials, where it could be used as a source of calcium oxide (for example, the production of porous ceramic tiles). However, high volume of sulphur dioxide emissions during the re-firing of fluidized fly ash in ceramic raw materials mixtures has been solved. The aim of the paper is definition of temperature ranges of anhydrite decomposition (formation of SO2 emission) from pure class C (fluidized) fly ashes from different sources (power plants) depending on granulometry of fly ash especially.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 487 ◽  
Author(s):  
Gabriela Rutkowska ◽  
Piotr Wichowski ◽  
Małgorzata Franus ◽  
Michał Mendryk ◽  
Joanna Fronczyk

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.


2018 ◽  
Vol 276 ◽  
pp. 110-115
Author(s):  
Martin Ťažký ◽  
Martin Labaj ◽  
Rudolf Hela

The by-products of energy industry are nowadays often affected by new limits governing the production of harmful gases discharged into the air. These stricter and stricter criteria are often met by electricity producers by changing the combustion process in thermal power plants itself. Nowadays, the SNCR (selective non-catalytic reduction) application is quite common in the combustion process in order to help reduce the nitrogen oxide emission. This article deals with the primary measures of thermal power plants, which in particular consist of a modified treatment of raw materials (coal) entering the combustion process. These primary measures then often cause the formation of fly ash with unsuitable fineness for the use in concrete according to EN 450. The paper presents the comparison of the physico-mechanical parameters of several fly ashes with a different fineness values. The primary task is to assess the impact of non-suitable granulometry in terms of EN 450 on the other physico-mechanical parameters of fly ashes sampled within the same thermal power plant. Several fly ashes produced in the Czech Republic and surrounding countries were evaluated in this way.


Author(s):  
Harry Miller ◽  
Anders T. Johnson ◽  
Markus Ahrens ◽  
T. Kenton Flanery

A team forms to address the challenge of low cost, low maintenance gas compression that can be quickly ramped up to meet peak demands. The Natural Gas Industry recognizes the importance of efficient, flexible compression equipment for the transmission of gas. In the early 1900s the Gas Industry met its compression objectives with many small reciprocating compressor units. As competition increased, Gas Companies began employing more cost effective larger units 3.7 MW (5,000 bhp) and eventually gas turbines 11+ MW (15,000+ bhp) became the prime mover of choice. While gas fired engine driven compressors are convenient for gas companies; they are becoming increasingly difficult to install. Environmental restrictions have tightened making permitting difficult. The larger gas turbine units seemed a solution because they were the low capital cost prime mover and clean burning. However, gas turbines have not yet achieved the high degree of flexibility and fuel efficiency gas transporters hoped. Flexibility has become an increasingly important issue because of the new “Peaking Power Plants” that are coming online. Gas companies are trying to solve the problem of low cost, low maintenance compression that can be quickly ramped up to meet peak demands. The idea of using electric motors to drive compressors to minimize the environmental, regulatory, and maintenance issues is not new. The idea of installing an electrically powered, highly flexible, efficient, low maintenance compressor unit directly into the pipeline feeding the load, possibly underground where it won’t be seen or heard, is a new and viable way for the gas and electric industries to do business together. This paper examines the application of totally enclosed, variable speed electric motor driven gas compressors to applications requiring completely automated, low maintenance, quick response gas pressure boosters. In this paper we will describe how a natural gas transporter, compressor manufacturer, motor manufacturer, and power company have teamed up to design the world’s first gas compressor that can be installed directly in the pipeline. We will discuss methodologies for installing the proposed compressor, the environmental benefits — no emissions, a small footprint, minimal noise — and the benefit of being able to install compression exactly where it is needed to meet the peaking requirements of today’s new loads.


Author(s):  
Madhurima Das ◽  
Siba Prasad Mishra

Coping with population growth, houses are built to meet the hike. The prerequisites for concrete and steel reinforcements have surged up globally since last 3 to 4decades. Shortage of natural building materials, increased wastes from coal based industries to augment carbon foot print has worried the engineers to reuse their wastes (such as fibres, powders, granules, etc.) as building materials ingredient. Glass fibre has improved flexural capabilities with fly ash dosages in cement concrete and alternately helps in restricting environmental degradation. Present research aims at investigating the impact of glass fiber (at 1%, 2% and 3% addition) and fly ash (dosages of 10% and 20% over the existing fly ash in PPC). The ingredients and microstructure of composites are found by either X-ray fluorescent spectroscopy or scanning electron microscope. Experimental evaluation results of the blended composite concrete parameters of RCC are experimentally evaluated and compared have shown that concrete with 10% cement substitution with fly ash and 3% fibre showed optimum compressive strength performance than the concrete without fibre and fly ash and also chemically resistant against commonly used M-20 grade of Concrete.


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