scholarly journals Modeling of compositions and predicting properties of modified mixtures for rough thin-layer coatings

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Dmitriy Chernykh ◽  
Mihail Pakin

In recent years, the approach to experimental and statistical research and optimization of complex multicomponent systems has changed radically. In various fields of scientific and technical research, methods of mathematical planning of experiments are successfully used. Their wide application significantly increases the effectiveness of research, as well as proves their universality and suitability in most studies of building materials. As a result, the authors present a method of mathematical planning of the experiment, which is used to optimize the composition and properties of modified mixtures for rough thin-layer coatings. This method allows a fairly complete and comprehensive assessment of the effect of components on the properties of modified mixtures and to obtain a mathematical model of the process in graphical form, as well as to obtain a theoretical model for evaluating and predicting the physical, mechanical and operational properties of the materials under study. In this article, the first stage of research was used to select the percentage of binder, hydrate lime and additives, and also studied the influence of the variation factor of these components on the physical and mechanical properties of the mixture. At the second stage, changes in response functions were investigated. The results of a complete three-factor experiment allowed us to establish rational ranges of values of the studied components in order to obtain mixtures for rough concolay coatings with optimal values of physical, mechanical and operational parameters.

2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.


2019 ◽  
Vol 964 ◽  
pp. 115-123
Author(s):  
Sigit Tri Wicaksono ◽  
Hosta Ardhyananta ◽  
Amaliya Rasyida ◽  
Feisha Fadila Rifki

Plastic waste is majority an organic material that cannot easily decomposed by bacteria, so it needs to be recycled. One of the utilization of plastic waste recycling is become a mixture in the manufacture of building materials such as concrete, paving block, tiles, roof. This experiment purpose to find out the effect of addition of variation of LDPE and PP thermoplastic binder to physical and mechanical properties of LDPE/PP/Sand composite for construction material application. In this experiment are using many tests, such are SEM, FTIR, compression strength, density, water absorbability, and hardness. the result after the test are the best composition of composite PP/LDPE/sand is 70/0/30 because its have compression strength 14,2 MPa, while density value was 1.30 g/cm3, for the water absorbability is 0.073%, and for the highest hardness is 62.3 hardness of shore D. From the results obtained, composite material can be classified into construction materials for mortar application S type with average compression strength is 12.4 MPa.


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.


2020 ◽  
Author(s):  
Ekaterina Gerasimova ◽  
Elizaveta Gumirova

The paper deals with the problem of utilization of red mud which is a waste product from alumina production using the Bayer method. The principal possible use for the red mud of JSC “Bogoslovsky aluminum plant” (Sverdlovsk region) for the compositions based on Portland cement is shown. It was found that the mud introduction accelerates beginning of the cement paste setting and thickens the paste reducing its mobility. It is concluded that the introduction of red mud up to 30 % is justified in terms of strength indicators. The work is carried out using mathematical planning of experiments. Keywords: red mud, Portland cement, active mineral additive, composition, properties, bauxite, chemical composition, cement stone strength, mathematical planning of experiments


2019 ◽  
Vol 7 (1) ◽  
pp. 126-136
Author(s):  
Hakan Çağlar ◽  
Arzu Çağlar

In this study, it is aimed to make improvements on blended brick (1) which is the first building material has a history of at least 10,000 years. To the blended brick which is a traditional material was kept constant at 5% the addition of fly ash which is industrial waste. It was aim of determine of the effect on the physical and mechanical properties of the blended brick using different ratios (5%, 10%, 15% and 20%) blast furnace slag. In the first stage, the production of fly ash-based blast furnace slag doped sample of blended brick was performed. In the second stage, a variety of experiments were applied to determine the physical and mechanical properties of the blended brick sample. As a result; It has been determined that unit volume weight and compressive strength decreases with the use of industrial wastes in blended brick production. They have occured an increase in porosity and capillary water absorption values. The use of industrial wastes in the production of blended bricks will contribute both improve the properties of the bricks and   the reduction of wastes left to the environment.


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.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Adnan Güven ◽  
Ahmet Bilgil

Pumice, cements (CEM I- and CEM II-type), waste fly and bottom ashes (IFA, GBA, and BBA) supplied from international companies were used to produce lightweight building materials, and physical-mechanical properties of these materials were determined. Axial compressive strength (ACS) values were found above the standards of 4 and 8 MPa (Bims Concrete (BC) 40 and 80 kgf/cm2 class) for cemented (CEM I) pumice-based samples. On the contrary, the ACS values of the pumice-based cemented (CEM II) samples could not be reached to these standards. Best ACS results (compatible with BC80) from these cemented lightweight material samples produced with the ashes were found in 50% mixing ratio as 10.6, 13.2, and 20.5 MPa for BBA + CEM I, GBA + CEM II, and IFA + CEM I, respectively, and produced with pumice were found as 8.4 MPa (same value) for GBA + pumice + CEM II (in 25% mixing ratio), BBA + pumice + CEM I (in 100% mixing ratio), and pumice + IFA + CEM I (in 100% mixing ratio), respectively. According to the results, cemented ash-based lightweight building material produced with and without pumice could widely be used for constructive purposes. As a result of this study, an important input to the ecosystem has been provided using waste ashes, whose storage constitutes a problem.


2021 ◽  
Vol 899 ◽  
pp. 137-143
Author(s):  
Yulia A. Sokolova ◽  
Marina A. Akulova ◽  
Baizak R. Isakulov ◽  
Alla G. Sokolova ◽  
Berikbay B. Kul’sharov ◽  
...  

The present paper considers the study of creep and deformation properties of sulfur-containing arbolit exposed to various compression stresses. Investigating the creep of lightweight arbolit concretes greatly affecting the performance of bearing and envelope structures draws a special attention during the last years. This issue is of particular relevance in the regions with hot and sharp continental climate. Arbolit concrete is one of the lightest building materials with low thermal conductivity and good soundproof properties. The modern postulates of theory and practice of creation, development of high-strength arbolit concretes on the base of composite sulfur-containing binders have become the methodological framework of the present research. While carrying out scientific research, the following standard measuring and analysis methods of physical and mechanical properties have been used for sulfur-containing arbolit composites. Experimental tests have been implemented on the 28-days samples made of sulfur-containing arbolit, with the cotton plant footstalks as an organic component. The researched samples were vapor sealed with the purpose to eliminate overlapping the processes of contraction and creep. The experimental results have shown that the analysis of prisms deformation in time demonstrates certain derivation from the pattern. Deformation of prisms made of sulfur-containing arbolit loaded at the low stress level were growing at a slower rate that the same deformations at a higher stress level. No derivation has been observed for the prisms of sulfur-containing haydite concrete. For both types of concrete, creep deformation has reached the values exceeding completely recoverable deformation by a factor of 2 or all the samples, the rapid growth of creep deformation has been observed after loading, followed by the gradual slowdown of deformation growth. For sulfur-containing lightweight concretes, as the test shown, the rate of creep deformation growth depends on the hardening curve in time reflecting the process of concrete hardening. This, if compared with sulfur-containing lightweight concretes, creep of sulfur-containing arbolit concrete is significantly lower that eventually leads to the loss of creep deformation at the same stress level. The obtained results can be used when manufacturing an efficient wall material for residential construction, including seismic areas.


Author(s):  
Viola Hospodarova ◽  
Nadezda Stevulova ◽  
Vojtech Vaclavik ◽  
Tomas Dvorsky ◽  
Jaroslav Briancin

Nowadays, construction sector is focusing in developing sustainable, green and eco-friendly building materials. Natural fibre is growingly being used in composite materials. This paper provides utilization of cellulose fibres as reinforcing agent into cement composites/plasters. Provided cellulosic fibres coming from various sources as bleached wood pulp and recycled waste paper fibres. Differences between cellulosic fibres are given by their physical characterization, chemical composition and SEM micrographs. Physical and mechanical properties of fibre-cement composites with fibre contents 0.2; 0.3and 0.5% by weight of filler and binder were investigated. Reference sample without fibres was also produced. The aim of this work is to investigate the effects of cellulose fibres on the final properties (density, water absorbability, coefficient of thermal conductivity and compressive strength) of the fibrecement plasters after 28 days of hardening. Testing of plasters with varying amount of cellulose fibres (0.2, 0.3 and 0.5 wt. %) has shown that the resulting physical and mechanical properties depend on the amount, the nature and structure of the used fibres. Linear dependences of compressive strength and thermal conductivity on density for plasters with cellulosic fibres adding were observed.


1994 ◽  
Vol 30 (8) ◽  
pp. 177-184 ◽  
Author(s):  
C. James Martel

This paper presents a new mechanical freezing concept for freezing alum or other hydroxide sludges as a conditioning step for dewatering. The basic concept is to freeze a thin layer of sludge on a continuously moving fabric belt. Sludge is attached to the belt by a vacuum drum belt filter which also removes one-half of the water and thus reduces the amount of sludge to be frozen. Filter leaf tests were conducted to determine the operational parameters and approximate production rates of this concept. These tests show that freezing alum sludge in thin layers will separate out the water as ice crystals and transform the solids into the same type of granular material produced in natural freezing beds. The average production rate of frozen sludge was 6.5 kg/hr.m2 at −20°C. The belt area needed for a 10,000-m3/day plant was estimated to be 48 m2. This concept has been patented by the U.S. Patent Office.


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