scholarly journals INVESTIGATION INTO TECHNOLOGICAL PARAMETERS OF BITUMEN BATCHING IN AN ASPHALT MIXING PLANT

2015 ◽  
Vol 21 (7) ◽  
pp. 958-965 ◽  
Author(s):  
Justas Bražiūnas
Keyword(s):  
Physical And Mechanical Properties ◽  
Void Content ◽  
Technological Parameters ◽  
Technological Processes ◽  
Road Pavement ◽  
Bitumen Content ◽  
Air Void ◽  
Production Conditions ◽  
Mineral Aggregates

An appropriate bitumen content and its properties in hot mix asphalt (HMA) mixture impact on the long-term mechanical strength of the laid asphalt pavement and the required road operation properties. During the production of a HMA mixture in an asphalt mixing plant (AMP), relationships between the structure and interaction of the mixture are established based on technological processes that specify bitumen batching and component mixing. These processes ensure the long-term strength, texture, evenness, the degree of damage and rheological properties of road pavement. The presented mathematical model enables us to determine the distribution of oxygen pressure by time in differently sized drops of bitumen during their fall into a mixer. The model considers oxygen diffusion, which depends on temperature, and heat conductivity, which depends on temperature, density and specific heat. An active experimental investigation under real production conditions demonstrated that the method of bitumen discharge from a batcher, temperature and time spent mixing materials with hot mineral aggregates impact on properties of bitumen binder within the produced HMA mixture. Parameters of technological processes for mixing of bitumen with mineral aggregates that occur in a bitumen batching system (BBS) are stochastic and impact on the composition of bitumen binder as well as physical and mechanical properties of the produced HMA mixture, namely, air void content, stability, flow and Marshall quotient.

scholarly journals Moisture and Frost Resistance of the Recycled Base Rehabilitated with the Foamed Bitumen Technology / Odpornosc Na Oddziaływanie Wody I Mrozu Podbudowy W Technologii Recyklingu Z Asfaltem Spienionym

2012 ◽  
Vol 58 (2) ◽  
pp. 185-198 ◽  
Author(s):  
M. Iwanski ◽  
A. Chomicz-Kowalska
Keyword(s):  
Frost Resistance ◽  
New Technology ◽  
Physical And Mechanical Properties ◽  
Climatic Conditions ◽  
Specific Production ◽  
Central European ◽  
Road Pavement ◽  
Foamed Bitumen ◽  
Cold Recycling ◽  
Production Conditions

Abstract The technology of recycling with foamed bitumen is a new technology of road rehabilitation. Due to the climatic conditions in the Central European countries, road pavement structure should be moisture and frost resistant. Because of its specific production conditions, this is especially important for pavements rehabilitation with the cold recycling technology. Determining the physical and mechanical properties, as well as moisture and frost resistance, depends on binder and filler contents. They are the key elements before its use for road building. The tests presented here have been performed on mineral recycled base mixes with foamed bitumen. The material from the existing layers was used. The content of bitumen binder amounted to 2.0%, 2.5%, 3.0% and 3.5%, while that of cement to 1.0%, 1.5%, 2.0%, 2.5%. The results were subject to the optimization process. This allowed to state that with the use of 2.5% foamed bitumen and 2.0% of cement, the base had the required properties, as well as the moisture and frost resistance.

scholarly journals The Influence of a Polymer Powder on the Properties of a Cold-Recycled Mixture with Foamed Bitumen

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4244 ◽  
Author(s):  
Przemysław Buczyński ◽  
Marek Iwański
Keyword(s):  
Physical And Mechanical Properties ◽  
Void Content ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Polymer Powder ◽  
Varied Chemical ◽  
Foamed Bitumen ◽  
Powder Type ◽  
Air Void ◽  
Reference Mixture

The paper investigates the influence of redispersible polymer powder (RPP) on the physical and mechanical properties of a cold-recycled mixture with foamed bitumen (CRM-FB). Four types of RPP with a varied chemical base were used: VA-VeoVA, VA-VeoVa-Ac, EVA and VA/VV/E/Ac. The polymer powder-modified cold recycled mixture with foamed bitumen, (P)CRM-FB, was composed of 45.8% reclaimed asphalt pavement (RAP), 45.8% natural aggregate (VA), 3.0% Portland cement CEM I 42,5R, 3.0% foamed bitumen 50/70 and 3.0% RPP, all dosed by weight. The reference mixture, (R)CRM-FB, served as a reference point for comparison. It was found that RPP improved the workability of the CRM-FB mixture. This results in a reduced number of compaction cycles and lower energy needed to obtain the air void content as in the reference mixture. In addition, the RPP modifier markedly increased the CRM-FB mixture cohesion (ITSDRY) and strength, by approximately 40–70%, depending on the RPP used. These findings are particularly important for CRM-FB mixtures designed for road bases. The present investigations confirmed the improvement of the CRM-FB mixture parameters after the modification with RPP, regardless of the powder type used.

Field Performance of Foaming Warm Mix Asphalt Pavement

2019 ◽  
Vol 2673 (3) ◽  
pp. 281-294 ◽  
Author(s):  
Shenghua Wu ◽  
Weiguang Zhang ◽  
Shihui Shen ◽  
Balasingam Muhunthan
Keyword(s):  
Field Performance ◽  
Warm Mix Asphalt ◽  
Void Content ◽  
Transverse Cracking ◽  
Water Based ◽  
Asphalt Content ◽  
Air Void ◽  
Air Void Content ◽  
Term Field

Water-containing and water-based foaming warm mix asphalt (WMA) technologies have been widely used in recent years but their long-term field performance is scarcely documented. This paper summarizes the field performances of six water-containing foaming and 10 water-based foaming WMA pavements across the United States and compares them with corresponding hot mix asphalt (HMA) pavements. Two series of field distress surveys were conducted to measure wheel-path longitudinal cracking, transverse cracking, and rut depth. Field cores were extracted to measure the in-place air void content, aggregate gradation, and asphalt content. The volumetric properties and field performance of foaming WMA and HMA control pavements were evaluated. The foaming WMA pavements showed slightly higher in-place air void (i.e., lower in-place density) than the HMA pavements. It was also found that the foaming WMA pavements in general had comparable or more wheel-path longitudinal cracking than the HMA pavements. The long-term field performance of foaming WMA pavements for transverse cracking and rutting were found to be similar to control HMA pavements. The study also reinforced the importance of in-place air void and asphalt content, finding that slightly higher asphalt content and lower in-place air void content may be beneficial for long-term resistance to cracking of asphalt pavements. As a result of the findings, the optimal pavement maintenance time was estimated to be four to five years since paving for full-depth pavement projects.

Long-Term Oven-Aging Effects on Fatigue and Initial Stiffness of Asphalt Concrete

1997 ◽  
Vol 1590 (1) ◽  
pp. 89-98 ◽  
Author(s):  
John Harvey ◽  
Bor-Wen Tsai
Keyword(s):  
Fatigue Life ◽  
Asphalt Concrete ◽  
Void Content ◽  
Aging Effects ◽  
Initial Stiffness ◽  
Asphalt Content ◽  
Flexural Beam ◽  
Air Void ◽  
Air Void Content

An investigation of the effects of long-term oven aging (LTOA) on initial stiffness and fatigue of asphalt concrete was made using two typical California asphalts, known to have different aging characteristics, in mixes with one aggregate. Asphalt content, air-voids content, and days of LTOA were varied independently. Stiffness and fatigue were evaluated using the controlled-strain flexural beam test developed by the Strategic Highway Research Program Project A-003A. The results indicated that both mixes exhibited an increase in initial stiffness with LTOA periods of up to six days. The sensitivity of beam fatigue life to LTOA depended on the asphalt. Beams containing Valley asphalt had virtually no change in fatigue life due to LTOA, whereas beams with Coastal asphalt showed some sensitivity to LTOA. For both asphalts, the average reduction in fatigue life from 6 days of LTOA was less than that caused by a 3 percent increase in air-void content or a 1 percent decrease in asphalt content. Simulations of thick and thin pavement structures were performed to reconcile the effects of LTOA, asphalt content, and air-void content on mix fatigue life and stiffness by evaluating their combined effects on predicted pavement fatigue life. The simulations indicated that aging, as induced by LTOA, increased fatigue life for all cases except one.

scholarly journals Asphalt Layer Density and Air Voids Content: GPR and Laboratory Testing Data Reliance

2020 ◽  
Vol 15 (3) ◽  
pp. 93-110
Author(s):  
Andrius Baltrušaitis ◽  
Audrius Vaitkus ◽  
Juris Smirnovs
Keyword(s):  
Asphalt Pavement ◽  
Relative Dielectric Permittivity ◽  
Void Content ◽  
Air Voids ◽  
The Road ◽  
Layer Density ◽  
Road Pavement ◽  
Ground Penetrating ◽  
Air Void ◽  
Air Void Content

The assurance of asphalt pavement layer compaction, expressed by ratio between field and laboratory bulk density and air voids content, is one of the main criteria of the durability of asphalt road pavement. Destructive measures should be applied and cores should be taken from the asphalt pavement seeking to determine the representative compaction level of the constructed asphalt layers. New methods are constantly being sought for fast, non-destructive and accurate asphalt layer density and air void determination on road. Ground Penetrating Radar (GPR) can allow determining the qualitative characteristics of asphalt pavement across the entire length of the road without causing damage to the road structure. Relative dielectric permittivity, usually called dielectric value or constant, is the leading property used in GPR applications on road pavement surveys. This article presents GPR measurement results from asphalt base and binder layers of four test sections. GPR measurements were conducted immediately after the end of asphalt layer compaction process. Test points on each layer were selected and density, air void content were determined by drilling cores and testing them in the laboratory. To estimate asphalt layer density and air void content, GPR data were analysed using different existing mathematical models. To justify the reliability of the data measured by GPR, results were checked by comparing them with the results measured directly on cores taken from the asphalt pavement layers.

scholarly journals Revealing changes in the technical parameters of the teat cup liners of milking machines during testing and production conditions

2021 ◽  
pp. 102-111
Author(s):  
Andriy Paliy ◽  
Elchyn Aliiev ◽  
Anatoliy Paliy ◽  
Katerina Ishchenko ◽  
Igor Lukyanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Elongation ◽  
Tensile Force ◽  
Operating Time ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Technological Parameters ◽  
Flow Process ◽  
Fourth Degree ◽  
Production Conditions

To implement effective cow milking, it is necessary to take into account the peculiarities of the milk flow process, the milking machine's adaptability to perform the given technological functions. The aim of research is to establish changes in the design and technological parameters and physical and mechanical properties of teat cup liner of milking machines during its testing and in production conditions. The results obtained will make it possible to make a rational choice of rubber, ensure an efficient milking process during its service life. It is found that the tensile strength of silicone teat cup liner at the beginning of operation was 1.6 times higher than that of a rubber compound, and after 6 months. operation – 1.7 times. With respect to the relative elongation, this difference was 1.4 times, and after operating time – 1.3 times. Studies have proven that rubber during operation changes its physical and mechanical properties: the length of the active part increased by 3.1 mm; wall thickness – 0.2 mm. It is found that the most intensively elastic properties of teat cup liner changed during the first 10–20 days. After 10 days, the closing vacuum increased by 16.6 % compared to the initial one, and after 20 days by 23.3 %, which amounted to 8.57 and 9.06 kPa, respectively. Up to 420 hours of operation, the clamping vacuum reached 11.3 kPa, which is 5.8 % lower than the requirements for toughening teat cup liner for rejection. In general, over the period of experiments, the average value of the vacuum of closing the opposite walls of teat cup liner increased from 7.35 to 12.43 kPa, which is 3.6 % higher than the norm (12 kPa). As a result of experimental studies, the regularity of the rubber tension force depending on the operating time in the form of a fourth degree polynomial is obtained. It is found that after 150 hours of operation, the tensile force of teat cup liner decreased by 21 %

scholarly journals A GPR-Based Pavement Density Profiler: Operating Principles and Applications

2021 ◽  
Vol 13 (13) ◽  
pp. 2613
Author(s):  
Nectaria Diamanti ◽  
A. Peter Annan ◽  
Steven R. Jackson ◽  
Dylan Klazinga
Keyword(s):  
Asphalt Pavement ◽  
Wave Impedance ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Air Voids ◽  
New Instrument ◽  
Pavement Engineering ◽  
And Performance ◽  
Air Void ◽  
Air Void Content

Density is one of the most important parameters in the construction of asphalt mixtures and pavement engineering. When a mixture is properly designed and compacted, it will contain enough air voids to prevent plastic deformation but will have low enough air void content to prevent water ingress and moisture damage. By mapping asphalt pavement density, areas with air void content outside of the acceptable range can be identified to predict its future life and performance. We describe a new instrument, the pavement density profiler (PDP) that has evolved from many years of making measurements of asphalt pavement properties. This instrument measures the electromagnetic (EM) wave impedance to infer the asphalt pavement density (or air void content) locally and over profiles.

scholarly journals Study of High-Temperature Properties of Asphalt Mixtures Used for Bridge Pavement with Concrete Deck

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4238
Author(s):  
Piotr Pokorski ◽  
Piotr Radziszewski ◽  
Michał Sarnowski
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Binder Content ◽  
Void Content ◽  
Concrete Bridge ◽  
Asphalt Mixes ◽  
Protective Layers ◽  
Concrete Bridge Decks ◽  
Air Void ◽  
Air Void Content

The paper presents the issue of resistance to permanent deformations of bridge pavements placed upon concrete bridge decks. In Europe, bridge asphalt pavement usually consists of a wearing course and a protective layer, which are placed over the insulation (waterproofing). Protective layers of bridge pavement are commonly constructed using low air void content asphalt mixes as this provides the suitable tightness of such layers. Due to increased binder content, asphalt mixes for bridge pavement may have reduced resistance to permanent deformations. The article presents test results of resistance to permanent deformations of asphalt mixes for the protective layers. In order to determine the composition of mixtures with low air void content and resistance to permanent deformation, an experimental design was applied using a new concept of asphalt mix composition. Twenty-seven different asphalt mixture compositions were analyzed. The mixtures varied in terms of binder content, sand content and grit ratio. Resistance to permanent deformation was tested using the laboratory uniaxial cyclic compression method (dynamic load creep). On the basis of experimental results and statistical analysis, the functions of asphalt mixture permanent deformation resistance were established. This enabled a determination of suitable mixture compositions for protective layers for concrete bridge decks.

Long-Term Forecasting and Optimization of Non-Stationary Well Operation Modes Through Neural Networks Simulation

2021 ◽  
Author(s):  
Roman Yurievich Ponomarev ◽  
Vladimir Evgenievich Vershinin
Keyword(s):  
Neural Network ◽  
Forecast Error ◽  
Optimal Solution ◽  
Hydrodynamic Modeling ◽  
Neural Network Modeling ◽  
Sharp Change ◽  
Technological Parameters ◽  
Production Wells ◽  
Long Term Forecasting

Abstract The article discusses the results of long-term forecasting of non-stationary technological modes of production wells using neural network modeling methods. The main difficulty in predicting unsteady modes is to reproduce the response of producing wells to a sharp change in the mode of one of the wells. Such jumps, as a rule, lead to a rapid increase in the forecast error. Training and forecasting of modes was carried out on the data of numerical hydrodynamic modeling. Two fields with significantly different properties, the number of wells and their modes of operation were selected as objects of modeling. Non-stationarity was set by changing the regime on one or several production wells at different points in time. The LSTM recurrent neural network carried out forecasting of production technological parameters. This made it possible to take into account the time-lagging influence of the wells on each other. It is shown that the LSTM neural network allows predicting unsteady technological modes of well operation with an accuracy of up to 5% for a period of 10 years. The solution of the problem of optimization of oil production is considered on the example of one of the models. It is shown that the optimal solution found by the neural network differs from the solution found by hydrodynamic modeling by 5%. At the same time, a significant gain in calculation time was achieved.

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