scholarly journals Improving energy efficiency through the use of waste heat products in the production of building materials

2021 ◽  
Vol 311 ◽  
pp. 07007
Author(s):  
Galina Medvedeva ◽  
Kamilla Giniyatova ◽  
Kamilia Minikaeva

Concern for the sustainable management and recycling of solid waste is becoming more visible in all sectors of the economy. This study explores the possibility of using coal ash residue (waste from Kazan CHPP-2) as a substitute for fine-grained aggregate in sulfur concrete. The trend towards an increase in the level of utilization of waste heat power engineering is an important task. The chemical composition, microstructure and mechanical properties, including density, water absorption, compressive strength and thermal conductivity of sulfur concrete, including coal ash with partial and complete sand replacement, were investigated and the results were compared with those for standard cellular concrete. The authors studied modern heat-insulating materials and materials from industrial waste products. The article analyzes the estimated thickness of the insulating material depending on the type of structure. Outside walls made of sulfur concrete, in addition to high strength properties, have high thermal and economic performance.

2018 ◽  
Vol 212 ◽  
pp. 01013
Author(s):  
Vadim Balabanov ◽  
Victor Baryshok ◽  
Nikita Epishkin

The sharply continental climate of the Irkutsk region is characterized by wide temperature intervals throughout the year. The repeated cyclicity of freezing and thawing of building materials in the water-saturated state influences the change in technical characteristics and the durability of concrete products and structures. The concrete products’ features in such climatic conditions create the need for the production of concretes with improved indicators of physical and mechanical properties. The effect of modifying additives on the technological characteristics of sulfur concrete is established. The effect of all elements of sulfur concrete on its strength and frost resistance. The composition of sulfuric concrete is obtained, which meets all the requirements and also has high strength and increased frost resistance. Formulations with a certain ratio of structural sulfuric concrete mixtures were developed. As a result of the use of technical sulfur in the composition of concrete products, the problem of utilizing annually accumulating reserves of technical sulfur is partially solved. The strength properties of sulfuric concretes easily compete with high-quality brands of concrete, special types of concretes that have in their composition additives.


2015 ◽  
Vol 1085 ◽  
pp. 312-315
Author(s):  
Oleg L. Khasanov ◽  
Edgar S. Dvilis ◽  
Zulfa G. Bikbaeva ◽  
Valentina V. Polisadova ◽  
Alexey O. Khasanov ◽  
...  

Ceramics samples in the form of a parallelepiped with high strength characteristics have been made. For the manufacture of the ceramics samples a powder mixture from submicron В4С powder with additives (1 wt%, 5 wt%, 10 wt%) of boron carbide nanopowder was used. The physical properties of the powder mixtures and strength properties of sintered ceramics have been studied. It was shown that the use of submicron fractions of the boron carbide powder together with nanoadditives is a determining factor in the formation of dense fine-grained structure providing improved physical and mechanical properties of the ceramics.


Food Industry ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 32-43
Author(s):  
Nadezhda Makarova ◽  
Natalya Eremeeva ◽  
Yana Davydova

Edible film spread worldwide as an alternative to biodegradable polymer film can partially replace it as a packaging material for a number of food products. The article presents data on the study of samples of one-, two-, three-, four-, five-, six-, seven-, eight-, nine-, ten-layer edible films. Edible films are based on one of the most common types of fruit – apples. The film peculiarity is the Apple pomace introduction into its composition, which is currently not used enough in the food industry and is waste. The researchers studied: a) organoleptic properties (appearance, color, taste, aroma, chewability), surface microstructure of edible films using the laser microscopy; b) film structure by the IR spectroscopy; C) the ratio of the film to water, to the effects of high and low temperatures; d) strength properties. Research results show that the edible multi-layer film based on Apple raw materials with the addition of Apple pomace is quite suitable for organoleptic indicators for use. Despite the presence of individual cracks and voids in the film structure, it has high strength characteristics, is moderately resistant to water and low temperatures, but loses its plastic properties when MV-heating.


Alloy Digest ◽  
2018 ◽  
Vol 67 (12) ◽  

Abstract MHZ 420 (mininum yield strength of 420 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-831. Producer or source: ThyssenKrupp Steel Europe AG.


Alloy Digest ◽  
2018 ◽  
Vol 67 (11) ◽  

Abstract MHZ 380 (mininum yield strength of 380 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-828. Producer or source: ThyssenKrupp Steel Europe AG.


2018 ◽  
Vol 188 (2) ◽  
pp. 187-196
Author(s):  
Pawel Ogrodnik ◽  
Bartosz Zegardlo

Modern dynamically developing building industry poses more and more complex challenges to building materials. Elevated constructions must satisfy a number of requirements including safety, durability and being environmentally friendly. The unfavorable impact of increased temperatures on the work of a construction structure is manifested by the change in the properties of the heated material and the occurrence of deformation, stresses and thermal scratches. These are particularly dangerous phenomena when they occur in elements with limited freedom of linear deformation. The purpose of the research presented in this article was to find a solution for concrete that is both resistant to spalling and characterized by high strength properties after heating. The main thesis put forward by the authors of the article is the assumption that deliberate concrete aeration will allow the introduction of evenly distributed micro air bubbles into its volume, which will constitute a reservoir for increasing the volume of water converting into water vapor as a result of a sudden increase in temperature. The presented schema enabled the assumption that the strength parameters of aerated concrete would decrease slightly in relation to non-aerated concrete, however it would be still possible to use in reinforced concrete constructions. As can be seen from the aforementioned analyzes, aeration modification can be an effective means of designing high temperature resistant concrete.


Alloy Digest ◽  
2019 ◽  
Vol 68 (1) ◽  

Abstract MHZ 460 (mininum yield strength of 460 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-835. Producer or source: ThyssenKrupp Steel Europe AG.


Fibers ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 79
Author(s):  
Valery Lesovik ◽  
Roman Fediuk ◽  
Mugahed Amran ◽  
Arbi Alaskhanov ◽  
Aleksandr Volodchenko ◽  
...  

Fibers of various origins are of great importance for the manufacture of new generation cement composites. The use of modified composite binders allows these highly efficient building materials to be used for 3D-printing of structures for various functional purposes. In this article, changes in building codes are proposed, in particular, the concept of the rheological technological index (RTI) mixtures is introduced, the hardware and method for determining which will reproduce the key features of real processes. An instrument was developed to determine a RTI value. The mixes based on composite binders and combined steel and polypropylene fibers were created. The optimally designed composition made it possible to obtain composites with a compressive strength of 93 MPa and a tensile strength of 11 MPa. At the same time, improved durability characteristics were achieved, such as water absorption of 2.5% and the F300 frost resistance grade. The obtained fine-grained fiber-reinforced concrete composite is characterized by high adhesion strength of the fiber with the cement paste. The microstructure of the developed composite, and especially the interfacial transition zone, has a denser structure compared to traditional concrete. The obtained materials, due to their high strength characteristics due to the use of a composite binder and combined fiber, can be recommended for use in high-rise construction.


Alloy Digest ◽  
2019 ◽  
Vol 68 (2) ◽  

Abstract MHZ 500 (mininum yield strength of 500 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-837. Producer or source: ThyssenKrupp Steel Europe AG.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 334
Author(s):  
Jaromir Moravec ◽  
Jiri Sobotka ◽  
Iva Novakova ◽  
Sarka Bukovska

Fine-grained steels belonging to the HSLA group (High-Strength Low-Alloy steels) of steels are becoming increasingly popular and are used in both statically and dynamically stressed structures. Due to the method of their production, and thus also the method use to obtain the required mechanical properties, it is really necessary to limit the heat input values for these steels during welding. When applying temperature cycles, HSLA steels in highly heated heat-affected zones (HAZ) reveal intensive grain coarsening and also softening behaviour. This subsequently results in changes in both mechanical and brittle-fracture properties, and the fatigue life of welded joints. While grain coarsening and structure softening have a major effect on the change of strength properties and KCV (Charpy V-notch impact toughness) values of statically stressed welded joints, the effect of these changes on the fatigue life of cyclically stressed welded joints has not yet been quantified. The paper is therefore conceived so as to make it possible to assess and determine the percentage impact of individual aspects of the welding process on changes in their fatigue life. To be more specific, the partial effects of angular deformation, changes that occur in the HAZ of weld, and the notch effect due to weld geometry are assessed.


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