scholarly journals THEORETICAL PRINCIPLES AND EXPERIMENTAL DATA TO IDENTIFY STABILITY OF ASPHALT CONCRETE COMPONENTS IN FINALLY DOSED MINERAL MATERIALS

Transport ◽  
2002 ◽  
Vol 17 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Henrikas Sivilevičius

The duration of asphalt concrete functioning depends on the quality of the asphalt concrete mixture used to pave the road. Grading of hot fractions sieved through technological sieves of asphalt concrete mixture, their pollution with particles of different size as well as stability influence on the quality of an asphalt concrete mixture. Each j - (j = 1...., m) aggregate mineral material or mixture is made up of two (mineral powder, particle of size less than 0,09 or 0,071 mm, and sand, particle of size from 2 to 0,09 mm or 5-0,071 mm) or three (crushed stone, particle size is larger than 2 or 5 mm) mineral components (i = 1, ..., k) . When required technological operations of asphalt concrete mixture production are carried out, the quantity and stability of any i - component in mineral materials change when they move through an asphalt concrete mixer. The more stable the quantity of mineral components in mineral materials (especially in finally dosed) is, the more uniform the composition of asphalt concrete mixture is produced. The experiments showed that when asphalt concrete mixture is produced applying a traditional technology in an asphalt concrete mixer of model D-597, D-508-2A, D-645-3 andD-590, sieved hot fractions of 0–5 mm and 5–15 are polluted with particles of different size by more than 10 per cent; and this pollution is neither uniform nor stable. Following a well-known theory, an average quadratic deviation σ of arithmetic undersized particles sieved through laboratory sieves ~aggregate mineral materials is the greatest when their mean X makes up 50 per cent; therefore, hot fractions of 0–5 mm and 5–15 mm were produced on the experimental data obtained from production as well as regression equations σ = ƒ( X )of statistical indeces of cold mineral powder. The values of average quadratic deviations σ µij of mineral component quantities in those finally dosed mineral materials are obtained from curves drawn according to the regression equations. They can be used to estimate dispersion σ2 Gi of mineral component i in asphalt concrete mixture which depends on the accuracy and stability of technological factors of an asphalt concrete mixer.

2019 ◽  
Vol 945 ◽  
pp. 147-157 ◽  
Author(s):  
Sergei Sergeevich Inozemtcev ◽  
Evgeniy V. Korolev

The comparative analysis of quality indicators of asphalt concrete and methods of their control is discussed in the present article. Classifications of modifiers for improving the quality of asphalt concrete are given. Novel nanoscale modifier for the improvement the resistance to climatic influences on asphalt is developed. The nanomodifier is based on sols of iron hydroxide and silicic acid. Nanomodification consists in processing of the mineral component by nanomodifier; such processing leads to the formation of nanoscale layer on the surface of the mineral carrier. As a mineral carrier we propose a highly porous mineral diatomite powder. The influence of the nanomodifier on the weathering resistance of asphalt concrete is investigated. Resistance to climatic influences was estimated by loss of strength after one nominal year of exposure. To simulate environmental impacts, an environmental chamber was used. The specimens were held in conditions that correspond to combination of summer and winter climate. One nominal year of exposure included 10 cycles of variable water saturation-drying at a temperature of 20 °C and 10 cycles of freezing-thawing (freezing was performed at –20 °C, thawing – at 20 °C). Saturation-drying and freezing-thawing duration was four hours. It was shown that by means of nanomodification the weathering resistance can be increased by 36 %.


2019 ◽  
Vol 8 (2) ◽  
pp. 51-62
Author(s):  
Ika Sulianti ◽  
Ibrahim Ibrahim ◽  
Agus Subrianto ◽  
Adelia Monita ◽  
Medici Medici

Styrofoam waste presents the environment issue because it is difficult to decompose. As an effort to recycle this pollutant, styrofoam can be utilized as an additive in asphalt concrete mixture. The use of additives aims to create a flexible pavement layer having good performance and meet the requirements. The purpose of this study is to find out whether the addition of styrofoam can improve the quality of asphalt mixtures, and look for alternative additives that can increase asphalt pavement performance. In this study, researchers used food container styrofoam as an addition and incorforated into Asphalt Concrete Wearing Course (AC-WC) mixture. The styrofoam content was 6.5%; 6.75%; 7% ; 7.25%; and 7.5% of asphalt weight. The optimum asphalt contentused is 5.5%. The value of the optimum stability was 3126,002 kg, found at 7.25% of styrofoam content. The best results of Marshall test was obtained at 6.5% of styrofoam content  with stability value  1362,045 kg, VIM value 4,96%, VMA 15,025%, VFA 67,800%, flow 3,44 mm, and MQ 416,338 kg / mm.


2002 ◽  
Vol 8 (2) ◽  
pp. 125-132
Author(s):  
Henrikas Sivilevičius ◽  
Valentinas Podviezko

A new partial conditional optimization method which enables to select the best ratio of imported fillers not only while designing the composition of asphalt concrete mixture but also while adjusting the composition of the produced asphalt concrete mixture according to the actual quality of hot fractions is presented. The constructed mathematical model, algorithm and the solved task prove that irrespective of the number of fillers (from 2 to 7 and more) the ratio of their mass can be selected which enables to produce an asphalt concrete mixture which meets the requirements of the composition project best. The mass ratio λ of imported fillers A 1 and reclaimed dust A 2, which settled and accumulated in the dry purification equipment of an asphalt concrete plant presented in Regulations DAT.AD-96 was taken into account for the first time. Methodological scientific novelty and a possibility to apply it in practice can improve the control of asphalt concrete mixture production.


2014 ◽  
Vol 584-586 ◽  
pp. 1197-1201 ◽  
Author(s):  
Albert Y. Bashkarev ◽  
Natalia N. Bespalova ◽  
Jarosław Rajczyk

<p>Asphaltic concrete is a composite material in which its mineral components: gravel, quartz sand and mineral powder is coupled by using bitumen. The experimentally determined that the quality of adhesion depends on the temperature at which all components had been mixing of hot asphalt mixes. However, the influence heating time remains unexplored. In this work the strength of compound was investigated on the samples of granite glued with using bitumen in a large range of temperature and time. It has been found that at a temperature of 140 degrees the strength increases significantly with time, but then starts to decline. The authors argue that the process of formation and destruction of adhesive compound bitumen and minerals can be described by the thermofluctuational theory of strength. Bitumen molecules on the boundary surface of the mineral become in a compressed state. The thickness of this layer can achieve 100 µm. The durability of road surfaces and the bond strength of all components asphalt concrete depends from quality of this indicator. Researches were conducted of the influence of the same temperature and time on the mechanical properties of the bitumen, but don’t found significant changes.</p>


2003 ◽  
Vol 9 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Henrikas Sivilevičius

Errors of optimal composition asphalt concrete mixture designed in the laboratory and their importance for road construction are investigated. After the analysis of asphalt concrete production according to the traditional technology, factors influencing its structure, characteristics and quality are systematised. Mathematical models of dependence of medium quadratic deviations of siftings of finite dosed mineral materials through control sieves on the means of siftings are estimated by a regressive analysis. Variations of grading of hot fractions 0–5 mm and 5–15 mm as well as cold mineral powder sieved through technological sieves of mixing equipment and influence of errors of dosing these mineral materials in the produced mixture on the stability of quantity of containing mineral components (crushed stone, sand and mineral filler) are identified. The main trends of asphalt concrete structure and handling of its equipment methods improvement are presented.


2021 ◽  
Vol 2021 (24) ◽  
pp. 193-205
Author(s):  
Ivan Kopynets ◽  
◽  
Volodymyr Kaskiv ◽  
Оleksii Sokolov ◽  
◽  
...  

Introduction. Mineral powder is an important structural component of asphalt concrete. Mineral powder is the output material obtained after crushing of rocks or powdery remains of the industry. It is made by grinding the following hard rocks: dolomitized limestone, dolomite, limestone. Non-carbonate raw materials and industrial wastes are also used as raw materials. Problem statement. Road construction with the arrangement of asphalt concrete pavements requires a number of components of these mixtures. Due to this, the need in scarce carbonate mineral powders is growing. Therefore, it is advisable to consider researches directed on studying a number of by-products of industry in order to use them as a mineral powder of asphalt concrete. Purpose. To analyze the existing experience of using industrial waste as a mineral powder in production of asphalt concrete mixture for further introduction and improvement of environmental safety and operational characteristics of pavement due to new road construction materials. Materials and methods. Analysis of information sources and experience in the use of industrial waste as a mineral powder and study of requirements for materials and their composition. Results. An analytical review of the experience of using industrial waste as a mineral powder was performed. Various materials have been studied and analyzed, requirements for materials, their particle size distribution, content in asphalt concrete mixture had been established. Conclusions. Analysis of information sources regarding use of industrial waste as a raw material for the production of mineral powder had determined that they are used in the whole volume in different countries and in most cases in road construction. It had been found that the use of various wastes during road construction is a viable option that needs further study.


Author(s):  
V. Yadykina ◽  
E. Kuznetsova ◽  
M. Lebedev

One of the main factors is the structure of asphalt concrete. The most important structural component in asphalt concrete is mineral powder, the quality of which depends on the technical and operational characteristics of the road surface. Different methods of processing mineral materials are used to improve the performance of asphalt concrete in Russia and abroad. In most cases, mechanical activation with organic substances is used during the grinding process. The article presents the results of research on the effect of treatment of mineral powder with the preparation GF-1 on its characteristics and on changes in the physical and mechanical properties of asphalt concrete, as well as on indicators for long-term water saturation. It is shown that as a result of modification, the mineral powder becomes hydrophobic, which has a positive effect on the physical and mechanical characteristics of asphalt concrete with its use. It is found that hydrophobization of mineral powder significantly reduces water saturation and swelling; increases water resistance during long-term water saturation (up to 90 days) of asphalt concrete samples. As a result of hydrophobization, the temperature sensitivity of asphalt concrete increases significantly. Therefore, the composite will work reliably in a wider temperature range.


2001 ◽  
Vol 7 (3) ◽  
pp. 213-223
Author(s):  
Henrikas Sivilevičius

The structure and sequence of technological operations of mixers for bituminous concrete mixtures, functioning in Lithuanian bituminous concrete mixing plants have been analyzed. The problems, which are subject to interest by the owners of bituminous concrete mixers, have been systematized. The necessity and objectives of quality evaluation of the functioning bituminous concrete mixers have been proved. A new multi-criteria mathematical model for determining quality of bituminous concrete—consisting of the sum of 4 group indicators, which evaluate quality of bituminous concrete mixture production in the mixer, environmental care, economy and technological universality—has been provided. The following 9 criteria make up the mathematical model, which can be used for calculation of quality indicator K of the working bituminous concrete mixer: accuracy of the bituminous concrete mixture content, produced in the mixer, ie the conformity of its component quantity with the project requirements (s); its temperature conformity with the temperature determined (t); its homogeneity in the batch, described by the mixing quality of batched components (h); environmental care, when the air is polluted by pollutants, thrown out from bituminous concrete (aa); bituminous concrete mixture production expenses as for one ton of (gi); level of physical and moral wear of the mixer (nl); expenses, needed for its maintenance and reconstruction (rr); use of its capacity when producing bituminous concrete mixture (pn); as well as technological universality of bituminous concrete mixer, ie ability to produce mixtures of different types and marks (tu). Coefficients of significance (importance) of all criteria are determined, using expert research methods. For this purpose a questionnaire for respondents (experts) has been prepared, which was filled by 43 scientists and production specialists, who have good knowledge of technology of bituminous concrete mixture production. The high value of concordation coefficient (W = 0,719) has shown good coordination of expert opinions, because X 2 = 247,5 is much higher than critical X 2 kr value with ε = 8 freedom level and 1% of accepted significance level, which makes up only 20,09. The experts believe that the most important criteria, reflecting the quality of bituminous concrete mixture are S([Xbar] j = 8,60), H([Xbar] j = 7,58), t(Xj = 7,3o), following in the range is the criterion AA (Xmac;j = 4,95), TU([Xbar]j = 4,56), GI([Xbar]j= 3,91), NL([Xbar]j = 3,47), and at the end least important RR([Xbar]j = 2,44) and PN([Xbar]j = 2,19). total sum of criteria is 45. The bituminous concrete mixer quality change when using it has been provided. The relation of its quality coefficient K reduction rhythm and level of conformity with the requirements imposed and constantly getting stricter has been analyzed.


2018 ◽  
Vol 251 ◽  
pp. 01028
Author(s):  
Alexey Ignatiev ◽  
Denis Gerasimov ◽  
Igor Golikov ◽  
Valeriy Gotovtsev

The paper presents the results of experimental studies to identify the possibility of using large-tonnage industrial mineral waste in the production of asphalt concrete mixtures. As a raw material for the production of asphalt used phosphogypsum - waste production of phosphoric acid, resulting from the processing of apatite. The reserves of this product are measured in millions of tons and are constantly replenished, stored in open dumps, representing a serious threat to the environmental situation in the surrounding areas. Phosphogypsum is a mineral powder material, the dispersion characteristics of which correspond to the mineral powder in the production of asphalt concrete. The method of production of granulated as-falto-concrete mixture developed by the authors of the article by the method of rolling involves the use of a significantly higher content of expensive mineral powder in comparison with typical mixtures. Therefore, the use of cheap phosphogypsum for these purposes is very attractive. However, the first attempts to obtain a granulated product based on phosphogypsum were unsuccessful - the asphalt-concrete mixture did not withstand the effects of moisture. Further studies allowed us to solve the problem of material resistance by modifying bitumen with polyethylene terephthalate, one of the most common household plastic waste. The subject of the article is devoted to the development of prescription and regime parameters of the process of obtaining new material. Test methods for asphalt concrete are strictly standardized in connection with which standard techniques were used. As a result of the research, an asphalt-concrete mixture was obtained, surpassing typical materials in many performance characteristics and allowing to solve a global environmental problem.


2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Khizar Dzhabrailov ◽  
Magomed-Emi Soltamuradov ◽  
Salam Gaziev

In connection with the sharp increase in the traffic flow, the problem of the durability of asphalt concrete pavements comes to the fore – their ability to maintain their properties within a certain period of time within certain limits. In many respects, the quality of future coverage is laid by the adaptability of the laying process, strict compliance with the requirements of project documentation and existing building codes and regulations (SNiP, GOST, ISO, etc.). However, the technology itself of the process of making asphalt concrete pavements is constantly evolving – new complexes are emerging, changes are being introduced to existing structures of machines for building coatings. Addition, reduction and combination of operations of the technological process, including, against the background of improving the quality and, as a result, the durability of the coating, reduce the complexity of the work performed, reduce the number of necessary staff – all of this has a positive effect on the economic component of construction, frees up additional funds. And, as you know, there is already enough evidence that the main factor hindering the development of the road network in the Russian Federation is, just the same, the need to spend huge budget funds (in 2016, about 30 billion rubles were allocated from the federal budget to repair existing roads due to their poor condition). In turn, the road-building industry, which is developing at a high pace, sets stringent requirements to ensure the required level of quality throughout the entire process, starting from the places of production of asphalt-concrete mixture (ABZ).


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