scholarly journals The Influence of Cement Substitution by Biomass Fly Ash on the Polymer–Cement Composites Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.

2020 ◽  
Vol 12 (2) ◽  
pp. 66-71
Author(s):  
DOMINIKA STAŃCZYK ◽  
BEATA JAWORSKA

Practical use of a new type of combustion waste such as an agricultural biomass fly ash in the building materials requires an assessment of its performance. The paper presents the investigation results on the influence of cement substitution (5% and 30%) by this ash on the cement and polymer-cement composites resistance to carbonation. The composites resistance was assessed on the basis of carbonation process over time (up to 360 days) using the phenolphthalein method. It was found that fly ash from agricultural biomass increases the susceptibility to carbonation of polymer-cement composites to a lesser extent than cement composites compared to composites containing siliceous coal fly ash.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3564
Author(s):  
Arnas Majumder ◽  
Laura Canale ◽  
Costantino Carlo Mastino ◽  
Antonio Pacitto ◽  
Andrea Frattolillo ◽  
...  

The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials, but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy performances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(m⋅K), while that of building materials with natural fibers was always lower than 0.162 W/(m⋅K) with lower values for compounds with recycled materials (0.107 W/(m⋅K)). Further developments are underway to analyze the mechanical properties of these materials.


2021 ◽  
Vol 4 (1) ◽  
pp. 27-34
Author(s):  
S-A.Yu. Murtazaev ◽  
A. Uspanova ◽  
M. Hadzhiev ◽  
V. Hadisov

during the implementation of the program to restore the housing stock of the Chechen Republic, as well as during the planned demolition of dilapidated housing, significant volumes of technogenic raw materials were generated, in particular, large volumes of brick and concrete scrap. Enterprises for the production of building materials and products also produce significant volumes of production defects, which accumulate over the years at landfills. Ceramic broken brick and broken brick dropouts are used to fill the roadbed, and the main part still goes to the dump and landfill, which is also an environmental problem. One of the promising ways to use dropouts and broken brick itself is to use them as secondary aggregates in concrete and mortars. This article discusses the issues of improving the quality of ceramic concrete mixtures, choosing the optimal composition and technology for mixing concrete mixtures using dust fractions of dropouts for crushing ceramic brick bricks


2018 ◽  
Vol 163 ◽  
pp. 03005 ◽  
Author(s):  
Beata Jaworska ◽  
Paweł Łukowski ◽  
Jerzy Jaworski

The aim of the presented research was to determine the influence of cement substitution with calcareous fly ash on the mechanical properties of polymer-cement composites. Coal combustion products such as calcareous fly ash have been already used in traditional cement composites as a part of cement and considered potential additions for concrete but its introduction into polymer-cement composites is still under preliminary investigation. The morphology of fly ash causes problems with its compatibility with polymer-cement binders but its insertion into those building materials is another way to utilize mineral combustion products that are cumbersome in storage and recycling. The influence of the mineral addition on polymer-cement composites containing 20% of polymer was especially taken into consideration. Mechanical properties of polymercement mortars modified with calcareous fly ash were tested after 28 and 90 days of curing. As a part of preliminary study, activity index of mineral addition was determined. Polymer-cement composites containing calcareous fly ash were characterized by higher flexural and tensile strength comparing to standardized mortar, even for the mortars containing 40% of mineral addition. The negative effect of the polymer-cement composites modification with calcareous fly ash was especially observed on the compressive strength of this composites.


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.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3398 ◽  
Author(s):  
Nikola Bilandžija ◽  
Tajana Krička ◽  
Ana Matin ◽  
Josip Leto ◽  
Mateja Grubor

Biomass obtained from cultivated energy crops is one of the raw materials with the highest potential in renewable energy production. Although such biomass can be used in production of lignocellulose bioethanol, it is currently mostly used as solid fuel for generating heat and/or electric energy via combustion processes. Calorific values, proximate and ultimate analysis, cell structure and micro- and macro-elements data are considered as basic parameters in the valorization of fuel properties during biomass combustion processes. Energy crops are cultivated with the aim to produce the largest possible quantity of biomass with minimal agro-technical inputs. One of these crops is Sida hermaphrodita (L.) Rusby. Given the fact that the chemical composition of biomass is influenced by a number of agro-ecological and agro-technical factors, the aim of this work was to determine the fuel properties of Sida hermaphrodita biomass obtained from three different harvest seasons (autumn, winter and spring) and cultivated in the area of the Republic of Croatia. On the basis of these investigations it was possible to conclude that harvest delaying towards spring season had a positive impact on suitability of using biomass of Sida hermaphrodita in the combustion process, which primarily means significant lowering the contents of moisture (18.64%), ash (1.94%), and nitrogen (0.65%), but also means increasing the contents of fixed carbon (6.21%) and lignin (25.45%).


2011 ◽  
Vol 239-242 ◽  
pp. 524-527
Author(s):  
Su De Ma ◽  
Guo Lin Song ◽  
Zong Cheng Miao ◽  
Deng Wu Wang

Microencapsulated phase change material (MEPCM) was successfully prepared by using paraffin as the core material and PMMA as shell material. Both raw materials are innocuous, cheap and rich in resource. The influences of the key factors (i.e. emulsifier, stabilizer, concentration of the oil phase) on synthesis reaction were systematically evaluated. Conditions of synthesis reaction were also optimized. The relevant research results indicate that the prepared microcapsules are regular spheres with smooth and compact surface. The diameter of these spheres ranges from 1 to 2 mm. No obvious overcooling or overheating phenomena can be observed even when the content of paraffin of MEPCM reaches approximately 50 wt%. TGA analyses indicate that the heat resistance of the microcapsule increases by 10 °C compared to the pure paraffin. Accelerated thermal cycling tests also verify that the MEPCM displays good thermal reliability. The MEPCMs synthesized in the current study have potentials for thermal energy storage purposes such as PCM slurries, textiles and building materials.


1992 ◽  
Vol 00 (8) ◽  
pp. 4-4 ◽  
Author(s):  
Eric A. Draper ◽  
Jan Skalny

The need for continued rehabilitation of our concrete infrastructure has lead to the adaptation of modern “state-of-the-art” analytical methods for the characterization of concrete and other cementitious materials. Some of these techniques have not, until relatively recently, been commonly associated with the evaluation of concrete but are very useful both as tools for quality assurance and in the determination of the extent of existing damage. The technique of interest here is the coordinated electron-optical microscopic evaluation of concrete.Concrete is the most widely used building material in the world. Contrary to popular belief, concrete is not inert but chemically very complex and dynamic. While it is true that, pound for pound, concrete and its raw materials (cement, aggregate and water} are the most inexpensive building materials available for construction, it is also true that it responds to its environment in numerous and sometimes very subtle ways. These responses may sometimes result in a loss of durability and tremendous amounts of time and money being expended while searching for the cause(s) of the problem and providing a cost-effect solution A quick survey of any large metropolitan area and the on-going construction repairs to highways and bridge decks there will quickly confirm this.


2018 ◽  
Vol 195 ◽  
pp. 01023 ◽  
Author(s):  
Ari Widayanti ◽  
Ria Asih Aryani Soemitro ◽  
Hitapriya Suprayitno ◽  
Januarti Jaya Ekaputri

Fly ash is a by-product obtained from coal combustion process. Some of the utilization of fly ash is to produce geopolymer products which have high compressive strength, fire, chemical resistance. This paper proposes fly ash from unit 1-7 Suralaya Power Plant Indonesia. The aims of this study are to obtain characterization of fly ash and mechanical properties of geopolymer paste based on variations of the alkali activator ratio. The method was based on previous research and laboratory investigation. XRF and compressive strength were analysed in this study. Alkali activator was obtained from NaOH and Na2SiO3 mixture. The ratio of Na2SiO3 to NaOH was in the range of 0.5-2.5. Geopolymer paste was casted in acrylic cylinders with a diameter of 2 cm and a height of 4 cm. The curing was conducted at room temperature until the day for the compressive strength test at 28 days. The result showed that the fly ash is classified as F class. Increasing the alkali activator ratio influenced the strength. The best composition of geopolymer paste is made with NaOH 8M, and the mass ratio of Na2SiO3 to NaOH is 2.5. This composition produced compressive strength of 98.6 MPa.


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