scholarly journals PROBABILITY METHODS OF ANALYSIS OF ASSESSMENT OF THE CONDITION OF ROAD CLOTHES IN USE

2021 ◽  
Vol 6 (166) ◽  
pp. 88-93
Author(s):  
A. Batrakova ◽  
S. Urdzik
Keyword(s):  
Probabilistic Models ◽  
Physical And Mechanical Properties ◽  
Climatic Conditions ◽  
Geometric Parameters ◽  
Probabilistic Methods ◽  
Necessary Condition ◽  
Intermediate Layers ◽  
New Construction ◽  
Pavement Structure ◽  
Probability Methods

This article is a continuation of the analysis of methods and criteria for assessing the condition of non-rigid pavement, which contains in its structural layers such hidden defects as cracks, material disintegration, violation of the structure of intermediate layers of monolithic material and others. The variety of models for assessing the condition of the pavement with destruction is explained by: variability of soil-geological, climatic conditions of operation of pavement; the variety of physical and mechanical characteristics of the materials of the structural layers of the pavement and the soil of the ground; heterogeneity of geometric parameters of pavements in the longitudinal and transverse profiles. According to many scientists to assess the condition of the pavement is a necessary condition for the use of methods of probabilistic analysis. Methods of designing and assessing the condition of the pavement structure must take into account the principles of reliability, including probabilistic methods of reliability analysis. Most of the considered probabilistic models for assessing the condition of pavement are focused on the design of new construction, which allows not to take into account the patterns of changes in physical and mechanical properties of materials of structural layers and their geometric parameters during operation. However, the most relevant is to assess the condition of pavement with damage, including hidden cracks. Much of the article is devoted to the analysis of this area of research. According to the results of the analysis, it is concluded that probabilistic methods allow to take into account the heterogeneity of parameters that characterize the stress-strain state of the pavement structure and can be used in models to assess the condition of pavement with cracks in layers of monolithic materials.

Technological and Economic Aspects of Intensive Gardening Development in Russia

2020 ◽  
pp. 28-36
Author(s):  
L.A. Velibekova ◽  
◽  
Sh.M. Magomedgadgiev ◽  
Keyword(s):  
Climatic Conditions ◽  
Necessary Condition ◽  
Healthy Lifestyles ◽  
Current State ◽  
Nursery Management ◽  
The Russian Federation ◽  
The Republic ◽  
Further Development ◽  
Key Industry ◽  
Fruit Plantations

The article notes that the growing popularity of healthy lifestyles contributes to the increase in consumption of fruits and berries. At the same time, the analysis of the dynamics of the gardening industry for 2000-2018 shows that the problem of providing fresh fruits and berries to the population remains one of the most important. Based on actual data, linear and logarithmic models of time series of key industry indicators for the period 2010 – 2019 have been compiled. Calculations showed that in the Russian Federation as a whole the trend of reduction of sown areas of perennial fruit plantations will continue with growth of yield and gross fees. In this regard, the issues of distribution and introduction of gardens of intensive type are updated. An overview of the views of domestic scientists-gardeners on the concept of “intensive garden” is given. It has been established that the distribution of intensive gardens is possible only if there are favorable natural and climatic conditions and a developed scientific and production base of nursery management. The current state and problems of gardening in one of the leading regions – the Republic of Dagestan - are considered. A significant technological lag of region in the further development of intensive horticulture has been identified. Various directions of intensification process in horticulture as the main and necessary condition of growth of efficient and sustainable production are summarized.

Research changes in the properties of butadiene-nitrile rubber under various aging conditions

2021 ◽  
pp. 009524432110290
Author(s):  
Mariya L Davydova ◽  
Aytalina F Fedorova
Keyword(s):  
Accelerated Aging ◽  
Physical And Mechanical Properties ◽  
Exposure Period ◽  
Climatic Conditions ◽  
Nitrile Rubber ◽  
Sterically Hindered Phenols ◽  
Loading Mode ◽  
Hindered Phenols ◽  
The Republic ◽  
Butadiene Nitrile Rubber

This article represents the results of a study of changes in the properties of vulcanizates based on BNR-18 butadiene-nitrile rubber containing as stabilizers the experimental spatially hindered phenols Stafen, CO3, CO4, and industrial antioxidant 6PPD, after accelerated aging (100°C 96 h) and aging under full-scale exposure in extreme climatic conditions of the Republic of Sakha (Yakutia) during 2 years. In winter, the air temperature reached—48°C, in summer—+36.1°C. It is shown that the experimental sterically hindered phenols more effectively under natural exposure conditions. They are characterized by the most stability in terms of strength throughout the entire exposure period. Under conditions of accelerated aging, the vulcanizate containing the industrial antioxidant 6PPD is characterized by the greatest stability of physical and mechanical properties. According to the viscoelastic characteristics obtained in the dynamic loading mode, the contribution of the presented stabilizers in maintaining resistance to temperature and deformation effects compared with unstabilized rubber is confirmed.

Comparison of Probabilistic and Possibility Theory-Based Methods for Design Against Catastrophic Failure Under Uncertainty

1999 ◽  
Author(s):  
Efstratios Nikolaidis ◽  
Harley Cudney ◽  
Sophie Chen ◽  
Raphael T. Haftka ◽  
Raluca Rosca
Keyword(s):  
Probabilistic Models ◽  
Failure Modes ◽  
Possibility Theory ◽  
Probabilistic Methods ◽  
Sufficient Information ◽  
Catastrophic Failure ◽  
Design Problems ◽  
Available Information ◽  
Theoretical Foundations ◽  
Better Than

Abstract This paper compares probabilistic and possibility-based methods for design against catastrophic failure under uncertainty. It studies the effect of the amount of information on the effectiveness of each method. The study is confined to problems where the boundary between survival and failure is sharp. First, the paper examines the theoretical foundations of probability and possibility. It also compares the two methods when they are used to assess the risk of a system. Finally, it compares the two methods on two design problems. A major difference between probability and possibility is in the axioms about the union of events. Because of this difference, probability and possibility calculi are fundamentally different and one cannot simulate possibility calculus using probabilistic models. It is shown that possibility-based methods can be less conservative than probability-based methods in systems with many failure modes. On the other hand, possibility-based methods tend to be more conservative than probability-based methods in systems that fail only if many unfavorable events occur simultaneously. Probabilistic methods are better than possibility-based methods if sufficient information is available. However, the latter can be better if little information is available. A principal reason is that it is easier to identify the most conservative possibilistic model than the most conservative probabilistic model that is consistent with the available information.

scholarly journals Concrete based on sulfur binder being modified with inorganic additives

2018 ◽  
Vol 212 ◽  
pp. 01013
Author(s):  
Vadim Balabanov ◽  
Victor Baryshok ◽  
Nikita Epishkin
Keyword(s):  
Frost Resistance ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strength Properties ◽  
Climatic Conditions ◽  
Freezing And Thawing ◽  
Concrete Mixtures ◽  
Irkutsk Region ◽  
Water Saturated

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.

Research of Air Flows Dynamics at Construction Works in the Condition of Urban Built-Up Areas

2018 ◽  
Vol 875 ◽  
pp. 183-186 ◽  
Author(s):  
I.V. Stefanenko ◽  
Valery N. Azarov ◽  
Katerina A. Trokhimchuk ◽  
Marina V. Trokhimchuk
Keyword(s):  
Dust Emission ◽  
Physical And Mechanical Properties ◽  
Simulation Modelling ◽  
Climatic Conditions ◽  
Fine Dust ◽  
Software Applications ◽  
Physico Chemical ◽  
Anthropogenic Development ◽  
Air Flows ◽  
Construction Works

The paper shows that the fulfillment of construction works influences the level of fine dust content in urban environment. Investigations of fine dust emissions in the zones of earth excavations and soil spoil banks caused by construction works were carried out. The authors conducted an integrated investigation of the physico-chemical processes in the surface layer of the atmosphere in the course of construction works, which was based on the field and computational experiments. With the help of a laboratory wind-tunnel plant, it was revealed that the character of dust emission during the development of dispersive massifs depends on the climatic conditions, in particular on the wind velocity and the physical-and-mechanical properties of the rocks (humidity, porosity, plasticity indices). A specific-purpose GIS application has been designed which allows modelling the dynamics of air flows in the territories with anthropogenic development. The application is based on the methods of mathematical and simulation modelling, the methods of visualization and surface plotting as well as the methods of software applications development.

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.

Vehicle Risk Level Estimation by Using Experimental Trajectories in Bend

2011 ◽  
Author(s):  
Abdourahmane Koita ◽  
Dimitri Daucher ◽  
Michel Fogli
Keyword(s):  
Probability Density ◽  
Reliability Analysis ◽  
Probabilistic Models ◽  
Hermite Polynomials ◽  
Probabilistic Methods ◽  
Risk Level ◽  
General Context ◽  
Risk Levels ◽  
Modelling Uncertainties ◽  
Non Gaussian

This paper tackles the general context of road safety, focussing on the light vehicles safety in bends. It consists to use a reliability analysis in order to estimate the failure probability of vehicle trajectories. Firstly, we build probabilistic models able to describe measured trajectories in a given bend. The models are transforms of scalar normalized second order stochastic processes which are stationary, ergodic and non-Gaussian. The process is characterized by its probability density function and its power spectral density estimated starting from the experimental trajectories. The probability density is approximated by a development on the Hermite polynomials basis. The second part is devoted to apply a reliability strategy intended to associate a risk level to each class of trajectories. Based on the joint use of probabilistic methods for modelling uncertainties, reliability analysis for assessing risk levels and statistics for classifying the trajectories, this approach provides a realistic answer to the tackled problem.

The Idea of Contrasted Differentiation

1936 ◽  
Vol 73 (5) ◽  
pp. 228-238 ◽  
Author(s):  
Arthur Holmes
Keyword(s):  
Basaltic Magma ◽  
Necessary Condition ◽  
Residual Liquid ◽  
Continuous Separation ◽  
Intermediate Composition ◽  
Rock Types ◽  
Crystallization Differentiation ◽  
Intermediate Layers ◽  
Intermediate Rock ◽  
Basic Rocks

As early as 1915, it was made clear by Bowen that, given continuous separation of crystals from the successive residual liquids of a consolidating magma which was initially basaltic in composition, the inevitable result would be a gabbroic rock in depth, a granitic one above, and “various intermediate types in the intermediate layers”. As a necessary condition to the evolution of a magmatic residuum of granitic composition, this process of progressive crystallization differentiation involves the generation of intermediate rock-types from residual liquids of intermediate composition. Certain investigators, however, led by the authors of the Mull memoir (1924), have entirely overlooked the necessity of this condition. Faced with the association of contrasted acid and basic rocks, which is a conspicuous characteristic of many continental central complexes, they have attempted to account for the facts by introducing a modified conception of crystallization differentiation for which Nockolds has recently proposed the name contrasted differentiation. According to this conception, the residual liquid of consolidating basaltic magma is of granitic composition and can be separated in bulk from a crystalline gabbroic phase.

Analysis on Thermal Stresses Adaptability to High Grade Asphalt Pavement Structure in Qinghai-Tibet Plateau

2015 ◽  
Vol 723 ◽  
pp. 395-399
Author(s):  
Ning Li ◽  
Xue Yan Zhou ◽  
Yu Xiang Tian ◽  
Peng Wei Liu
Keyword(s):  
Low Temperature ◽  
Thermal Stresses ◽  
Asphalt Pavement ◽  
Structure Type ◽  
Climatic Conditions ◽  
Tibet Plateau ◽  
Large Temperature ◽  
Climate Conditions ◽  
Pavement Structure ◽  
Qinghai Tibet Plateau

Permafrostregions have harsh climate conditions, continuous low temperature, abrupt cooling, large temperature difference, winds, etc. It has an extremely obvious influencetoasphalt pavement structures and materials. Take Lhasa-Gongga airport highway as an example to analyze the low temperature cracking problem of asphalt pavement caused by the climatic conditions. Using finite element method to contrast and analyze the thermal stresses variation of different asphalt layer, and recommend suitable asphalt pavement structure for Qinghai-Tibet plateau permafrost regions.The results indicate that the thermal stresses of asphalt layer gradually reduce along with the thickness direction of structure, moment of maximum and minimum value also been delayed and thermal stresses of base cause is fairly few. It can reduce thermal stresses of base cause and asphalt layer effectively while using the AC-25, and 4cmAC13 + 6cmAC20 + 8cmAC25 is recommended for Lhasa-Gonggaairport highway pavement structure type.

Study of the Aging of Cold-Cured SKU-PFL Type Polyurethane Filled with Waste Products

2021 ◽  
Vol 899 ◽  
pp. 119-124
Author(s):  
Tatyana R. Safiullina ◽  
Elvira N. Nurieva ◽  
Lyubov A. Zenitova
Keyword(s):  
Mechanical Properties ◽  
Silica Gel ◽  
Physical And Mechanical Properties ◽  
Climatic Conditions ◽  
Petrochemical Production ◽  
Waste Products ◽  
Material Quality ◽  
Before And After ◽  
Microsoft Office

The article describes the results of aging of samples of cold-cured molded polyurethanes of SKU-PFL brand filled with zeolite and silica gel - wastes of petrochemical production. The samples were aged under normal climatic conditions for 5 years. Filling of the samples varied from 10 to 50 %wt. Investigations of physical and mechanical properties of the samples before and after aging were carried out, the basic indicators of material quality were calculated using Microsoft Office Excel package. As a result of researches it was established that after aging the basic physical and mechanical properties of cast polyurethanes of SKU-PFL brand of cold curing filled with zeolite and silica gel change insignificantly, however the best resistance to aging are in samples with 20 %wt. zeolite and 10 %wt. silica gel filling both before and after aging that allowed to recommend them for long-term use of articles.

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