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 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.

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.

Influence of CNT Addition to the Frost Resistance of Concrete

2018 ◽  
Vol 760 ◽  
pp. 30-34
Author(s):  
Tomáš Jarolím ◽  
Jiří Brožovský ◽  
Dominik Šácha ◽  
Naděžda Pizúrová
Keyword(s):  
Frost Resistance ◽  
Materials Science ◽  
Climatic Conditions ◽  
Central European ◽  
University Of Technology

Frost resistance of concrete is one of the main durability parameter of Central European climatic conditions. Nanoparticles are the most worldwide examining in materials science. In Brno University of Technology has been interested in nanoparticles for years. First steps were dedicated in identification of nanoparticles (CNT), their dosage and dispersion. After solving before mentioned steps the CNT implementation to concrete could happened. In article was experimentally verify influence of CNT addition to concrete frost resistance after 100 frost cycles. Per results it could be said that addition small dosage of CNT increased frost resistance of concrete.

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.

scholarly journals Research and Analysis on the Principle in Plant Cold Recycling for Foamed Bitumen and Mixture Performance

2021 ◽  
Vol 4 (6) ◽  
Author(s):  
Zecheng Ni ◽  
Shijing Chen ◽  
Yihuan Li ◽  
Hongxi Peng ◽  
Jiawen Liang ◽  
...  
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
External Factors ◽  
Asphalt Pavements ◽  
Huge Amount ◽  
Construction Waste ◽  
The Road ◽  
Road Performance ◽  
Foamed Bitumen ◽  
Cold Recycling

The early asphalt pavement in our country severely reduced the road performance due to various external factors during the use process. According to incomplete statistics, there are more asphalt pavements that need to be renovated and repaired every year in China, and the amount of construction waste such as asphalt concrete and other construction waste reaches 1,000. About ten thousand tons. If such a huge amount of construction waste is not used, it will inevitably cause great pollution to the environment. If it can be reused, not only will it be environmentally friendly and energy-saving, it will also save more than one billion yuan in costs. In view of the above problems, this article conducts related Research and Analysis on the Principle in Plant Cold Recycling for Foamed Bitumen and Mixture Performance to provide reference for future projects.

scholarly journals Factor Influencing Adaptation Choices Employed by Farmers Against Climate Change to Improve Rice Yield in Bugarama Wetland in Rwanda

2020 ◽  
Vol 2 (1) ◽  
pp. 12-22
Author(s):  
Esther Nyirandorimana ◽  
Ezekiel Ndunda ◽  
John Muriuki
Keyword(s):  
Climate Change ◽  
Rice Yield ◽  
New Technology ◽  
Climatic Conditions ◽  
Descriptive Research ◽  
Changing Climate ◽  
Step Model ◽  
Rice Yields ◽  
Market Distance ◽  
Adaptation Method

The changing climate poses a great challenge to many wetlands productivity worldwide. Rice production in wetlands is a major source of livelihood in developing countries such as Rwanda. This study aimed at determining the factors influencing adaptation methods when farmers perceive the changing climate at Bugarama Wetland Rice Scheme in Rwanda. A descriptive research design was used by this study, whereby quantitative and qualitative data was collected. The analysis was based on data collected from 300 selected farmers using systematic random sampling method. We employed descriptive statistics to assess how farmers perceive the effects of climate change and descriptively measured the new adaptation methods used by farmers in Bugarama to increase their yields. The study adopted Heckman two-step model to determine factors that influence adaptation choices, this analysis procedurally required farmers’ knowledge of perception that makes them respond to the effects of changes in climatic conditions by the use of new adaptation methods. The results deduced that level of education (p =0.019), extension access (p=0.001), market distance (p=0.002) and rice income (p < 0.001) had a probability of influencing farmers perceptions about climate change thus need to adapt. Based on the outcome model, results showed that extension access (p < 0.001), household size (p= 0.098), market distance (p= 0.047), rice income (p =0.032), farmers-to-farmers contact (p < 0.001) and effects of climate change on rice (p=0.038) had a greater probability of influencing farmers choice of adaptation method used to improve rice yields. To conclude, the study found that access to informational facilities and rice income, influenced farmers’ perceptions while extension access, rice income, market distance, farmers-to-farmers contact and effects of climate change on rice yield strongly had a probability of determining farmers’ choice of adaptation. This study recommends that the Rwandan government and local administrators need to develop a strategy that would allow farmers to access information facilities about new technology so as to adapt to the effects of climate change thus improve their rice yields.

scholarly journals Application of the foamed bitumen and bitumen emulsion to the road base mixes in the deep cold recycling technology

2016 ◽  
Vol 11 (4) ◽  
pp. 291-301 ◽  
Author(s):  
Marek Iwański ◽  
Anna Chomicz-Kowalska
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Base Layer ◽  
The Road ◽  
Road Base ◽  
Bitumen Emulsion ◽  
Recycling Technology ◽  
Indirect Tensile ◽  
Foamed Bitumen ◽  
Cold Recycling

This paper presents findings of a study concerning the influence of binder type on the mechanical properties of road base in the cold recycling technology. The principal aim of this investigation was to evaluate the mixes in scope of susceptibility to moisture and low-temperatures. In the comparative research foamed bitumen and bitumen emulsion were used in four different concentrations (2.0%, 2.5%, 3.0%, 3.5%). The materials used in the study were reclaimed from an existing road construction layers: reclaimed aggregate from the road base and reclaimed asphalt pavement obtained by milling the surface and binder course. Portland cement in 2.0% concentration was used as a hydraulic binder. The evaluated parameters were: indirect tensile strengths, tensile strength retained and indirect tensile stiffness modulus at 25 °C. These tests were complemented by an evaluation of susceptibility to moisture and frost according to modified procedures implemented by American researchers: Tunnicliff, Root and Lottman. Moreover, tests for low-temperature cracking were conducted according to Finnish standard. The investigations showed that the use of foamed bitumen for road base layer produced in the cold recycling technology results in better mechanical properties and resistance to moisture and frost compared to using bitumen emulsion. The use of 2.5% of foamed bitumen and 2.0% of Portland cement in the recycled road base allowed to meet the established criteria.

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.

Process of Shaped Metal Billets Production from Compositions Based on Iron Powder, Iron Oxide, and Binder

2017 ◽  
Vol 265 ◽  
pp. 250-258
Author(s):  
V.A. Dovydenkov ◽  
O.S. Zvereva ◽  
S.Ya. Alibekov
Keyword(s):  
Iron Oxide ◽  
Thermal Treatment ◽  
Solid Phase ◽  
New Technology ◽  
Physical And Mechanical Properties ◽  
Dimensional Accuracy ◽  
Uniform Density ◽  
Protective Medium ◽  
Experimental And Theoretical Studies ◽  
Mim Technology

A new technology of metal billets production by molding and thermal treatment of compositions based on iron powders of medium dispersion, fine powders of iron oxide, and the thermosetting binder, which provides for the required physical and mechanical properties of the material, is proposed. It is found that, at a certain concentration and dispersion of the components of the solid phase, the injection and direct compression molding of parts of complex shape (similar to the MIM-technology) is possible at pressures from 70 MPa to 100 MPa ensuring uniform density over the cross section. The established stages of thermal treatment of compositions, thermal behavior and protective medium ensuring uniformity of products, and chemical composition of the product material are presented in the paper. The experimental and theoretical studies of the dimensional accuracy of steel products obtained by the developed technology were carried out, and it was discovered that the produced parts were of the precision of steel parts produced by MIM-technology.

Sign in / Sign up

Export Citation Format

Share Document