scholarly journals Investigating mechanical properties of hot mix asphalt containing iron ore flotation tailing

2021 ◽  
Vol 10 (17) ◽  
pp. e122101724220
Author(s):  
Sérgio Pacífico Soncim ◽  
Jonas Henrique de Carvalho Oliveira ◽  
Marconi Oliveira de Almeida ◽  
Carlos Augusto de Souza Oliveira ◽  
Fernanda Maria Belotti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Iron Ore ◽  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Economic Value ◽  
Asphalt Mixture ◽  
Environmental Benefits ◽  
Environmental Damage ◽  
Creep Tests ◽  
Flotation Tailing

Studies involving the use of iron ore tailings from the beneficiation process in different market niches are increasingly necessary due to the large environmental damage caused by their disposal in dams, since they are waste generated in high volumes and which have low economic value for mining companies The main purpose of this study was to investigate mechanical properties of hot mix asphalt mixture containing iron ore flotation tailing. For this, a mixture containing iron ore flotation tailing and a control mixture with natural aggregates and stone dust were prepared according to the Marshall methodology and tests of stability and flow, indirect tensile strength, resilient modulus, fatigue test and dynamic creep tests were conducted. Results show that the mixture with iron ore flotation tailing had performed technically appropriate, due to the similarity of mechanical properties of the control mixture. Therefore, the results obtained revealed that the iron ore flotation tailing presented technical characteristics appropriate to its use incorporated into hot mix asphalt. In addition, their use as an alternative material in asphalt pavements can generate environmental benefits by reducing the volume of material deposition in tailings landfills and exploration areas for mineral aggregate mining.

Performance and Evaluation of Hot Mix Asphalt with an Addition of Lime Kiln Dust as a Mineral Filler Based on Western Australia Conditions

2018 ◽  
Vol 934 ◽  
pp. 212-216 ◽  
Author(s):  
Peerapong Jitsangiam ◽  
Hamid Nikraz ◽  
Korakod Nusit
Keyword(s):  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Hydrated Lime ◽  
Superior Performance ◽  
Mineral Filler ◽  
Lime Kiln ◽  
Performance And Evaluation ◽  
Kiln Dust ◽  
Lime Kiln Dust

This study demonstrates an assessment into the different effects of lime as a mineral filler for use in densely graded hot mix asphalt (HMA). Five percent by mass of hydrated lime and lime kiln dust (LKD) were added to an asphalt mixture as its mineral filler. A series of laboratory tests to evaluate stability and flow, resilient modulus and tensile stripping ratio with reference to a control mix (a commonly used HMA) were performed. The test results showed that mixing hydrated lime into a HMA mix could enhance superior performance of hydrated lime-HMA test samples for all tests, demonstrating no moisture susceptibility. Test samples of HMA with LKD also demonstrated moisture resistance and can offer a sustainable alternative to hydrated lime, yielding one quarter of the cost. The control mix proved to be an inadequate choice upon failing the stripping potential test and therefore deemed to be susceptible to moisture.

scholarly journals Influence of compaction temperature on the properties of Marshall specimens

2015 ◽  
Vol 10 (4) ◽  
pp. 309-315 ◽  
Author(s):  
Ivica Androjić ◽  
Sanja Dimter
Keyword(s):  
Mechanical Properties ◽  
Structural Design ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Maximum Density ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Compaction Temperature ◽  
Asphalt Mix ◽  
Very High

Compaction of hot mix asphalt is influenced by several factors; some related to the environment, some determined by mix and structural design and some by contractor during construction. The temperature of asphalt mixture has the biggest influence on the compaction of asphalt mixtures and their properties. The temperature of asphalt mixture affects viscosity of bitumen and achievement of the maximum density of asphalt mixture. This paper describes a laboratory study on the effects of different installation temperatures on the physico-mechanical properties of specimens of asphalt mixtures: stability, Marshall Quotient (stiffness), density, voids and voids filled with asphalt. By regression analysis of the test results the correlation of certain properties of asphalt mix and compaction temperatures was established. For all the models observed, the coefficients of determination are very high and indicate very solid links. The obtained research results indicate a pronounced effect of compaction temperature on each tested property of asphalt mix.

Influences of Crumb Rubber Sizes on Hot Mix Asphalt Mixture

2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Gizing Sami Hamad ◽  
Ramadhansyah Putra Jaya ◽  
Norhidayah Abdul Hassan ◽  
Md. Maniruzzaman A. Aziz ◽  
Mohd Ibrahim Mohd Yusak
Keyword(s):  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Engineering Properties ◽  
Dry Process ◽  
Alternative Material ◽  
Partial Interaction ◽  
Pavement Construction

Crumb rubbers (CRs) have been proposed as pavement components because they are waste materials. Previous studies have attempted to find alternative material in pavement construction that act as additives or property modifier. The current study presents a laboratory experiment using CR recycled from discarded vehicle tiresas additives in hot mix asphalt (HMA). CR was added using the dry process technique. Three rubber sizes were used with the following measurement: 0.15, 0.425, and 1.18mm. CR was added 2% of the weight of total aggregates. Bitumen80/100 penetration was used throughout the experiment. The effect of CR size on the mixture was investigated in terms of resilient modulus, indirect tensile strength (ITS), stability and dynamic creep. Experimental results revealed that the four engineering properties decreased when CR was added to HMA and when CR size was increased. However, the increasedCR size similarly increased the permanent deformation values. The data analysisshowed that 0.15mm CR is the most effective material for asphalt mixturebecause of the partial interaction between rubber particles and bitumen.

scholarly journals Evaluation of Permanent Deformation of CRM-Reinforced SMA and Its Correlation with Dynamic Stiffness and Dynamic Creep

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nuha Salim Mashaan ◽  
Mohamed Rehan Karim
Keyword(s):  
Resilient Modulus ◽  
Dynamic Stiffness ◽  
Permanent Deformation ◽  
Economic Value ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Green Technology ◽  
Waste Materials ◽  
Dynamic Creep ◽  
Waste Tyre

Today, rapid economic and industrial growth generates increasing amounts of waste materials such as waste tyre rubber. Attempts to inspire a green technology which is more environmentally friendly that can produce economic value are a major consideration in the utilization of waste materials. The aim of this study is to evaluate the effect of waste tyre rubber (crumb rubber modifier (CRM)), in stone mastic asphalt (SMA 20) performance. The virgin bitumen (80/100) penetration grade was used, modified with crumb rubber at four different modification levels, namely, 6%, 12%, 16%, and 20% by weight of the bitumen. The testing undertaken on the asphalt mix comprises the indirect tensile (dynamic stiffness), dynamic creep, and wheel tracking tests. By the experimentation, the appropriate amount of CRM was found to be 16% by weight of bitumen. The results show that the addition of CRM into the mixture has an obvious significant effect on the performance properties of SMA which could improve the mixture's resistance against permanent deformation. Further, higher correlation coefficient was obtained between the rut depth and permanent strain as compared to resilient modulus; thus dynamic creep test might be a more reliable test in evaluating the rut resistance of asphalt mixture.

scholarly journals Structural sensitivity of an asphalt pavement to asphalt binder content and mix design method

TRANSPORTES ◽  
2021 ◽  
Vol 29 (4) ◽  
pp. 2456
Author(s):  
Cássio Alberto Teoro Do Carmo ◽  
Géssica Soares Pereira ◽  
Geraldo Luciano de Oliveira Marques ◽  
Paulo Roberto Borges
Keyword(s):  
Mechanical Properties ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Binder Content ◽  
Asphalt Mixtures ◽  
Mix Design ◽  
Structural Sensitivity ◽  
Structural Responses

The goal of this study was to analyze the structural sensitivity of a flexible pavement, whose asphalt layers underwent variations in its mechanical properties due to the asphalt binder content and the mix design method Marshall and Superpave. A variation of ±0.5% within the optimum asphalt binder contents was used (service tolerance) considering possible permissible variations in the asphalt binder content during the asphalt mixture manufacturing process. The values of resilient modulus and indirect tensile strength (Brazilian test) of the resulting asphalt mixtures were applied to the reference pavement structure analyzed by the me-PADS software. The results show that the variations in the asphalt binder content and the asphalt mixtures design method influence the mechanical properties and corresponding structural responses of the pavement investigated: the asphalt layers designed by the Marshall method presented greater sensitivity to the variation in asphalt binder content, which may constitute a technical differential of asphalt mixtures designed by the Superpave method.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

New Paradigm for State Department of Transportation Environmental Initiatives: New York State’s Guidelines and Procedures

2000 ◽  
Vol 1702 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Gary McVoy ◽  
Mark Sengenberger ◽  
Elizabeth Novak
Keyword(s):  
New York ◽  
New York State ◽  
Cost Effective ◽  
State Department ◽  
Regulatory Compliance ◽  
Environmental Benefits ◽  
Environmental Damage ◽  
York State Department ◽  
Department Of Transportation ◽  
New Paradigm

Public-works agencies have an obligation to enhance the environment as opportunities arise. The New York State Department of Transportation (NYSDOT) has developed an environmental initiative to make an affirmative contribution to the environment, using the department’s organizational strengths. The environmental initiative is a paradigm shift applicable to all departments of transportation (DOTs). Conventional reactive regulatory compliance can reduce unnecessary environmental damage and sometimes gain grudging regulatory agency cooperation; however, it is not a positive, satisfying way of doing the people’s work. Through proactive steps, NYSDOT has become an important part of the state’s environmental solution (often at little or no additional cost) and has changed its working relationships with environmental agencies and groups. As these agencies and groups have become partners, instead of adversaries, permit-approval times have improved, mitigation costs have declined, morale has improved, and cost-effective environmental benefits are being realized. Procedures are outlined to apply the engineering capabilities of a DOT to the environmental-stewardship responsibilities shared by all governmental organizations.

Emissions Responsibility and Relative Importance of the Productive Sectors in Turkey: 2002-2011

2014 ◽  
Author(s):  
Celal Taşdoğan ◽  
Bilgen Taşdoğan
Keyword(s):  
Air Pollutants ◽  
Economic Value ◽  
Value Added ◽  
High Growth ◽  
Air Pollutant ◽  
Sustainable Growth ◽  
Environmental Damage ◽  
Relative Importance ◽  
Input Output ◽  
Key Sectors

Turkey has realized high growth rates during the period of 2002-2011, except in 2008 and 2009 years. It is thought that the rapidly growing in the country may cause a lot of environmental damage, especially air pollution problems. In other words, the productive sectors have produced two outputs which are economic value added and air pollutants. This study used input output matrixes are to find out the strategically important sectors as it is known key sectors and weak sectors caused the environmental effects in the country. For this purpose, it has been tried to investigate air pollutant quantities which caused by the production process of the sectors in the period of 2002-2011 and performed the input-output tables for Turkey constructed in the World Input Output Database (WIOD) Project. These input-output tables include the emission satellite accounts, which are CO2 emissions and other air pollutants, respectively N2O, CH4, N2O, NOx, SOx, CO, NMVOC and NH3, disaggregated for the 34 sectors. It is expected that the outcomes of the study may contribute to sustainable growth debates and environmental policy implementations in Turkey.

Counting Fish: Environmental Benefits Calculation for Avoided Costs Analysis in Urban Water Use Efficiency Planning

2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Katie Shulte Joung ◽  
Mary Ann Dickinson
Keyword(s):  
Water Conservation ◽  
Economic Value ◽  
Environmental Benefits ◽  
Urban Water ◽  
Environmental Benefit ◽  
Conservation Programs ◽  
Water Utility ◽  
Water Savings ◽  
Urban Water Use ◽  
Use Efficiency

This report documents a project undertaken for the California Urban Water Conservation Council to create a method to calculate water utility avoided costs and assign economic value to the environmental benefits of raw water savings as a result of implementing urban water conservation programs. It is assumed that water savings associated with implementation of conservation programs can be quantified and represented as a reduction in the demand for water from a particular set of supply sources. This demand reduction may in turn result in a change to the availability of an environmental benefit provided by that source. Environmental valuation, as it is applied here, is relatively new and there are numerous complications, ambiguities, data gaps and differences of opinion in the application of the methodology. For that reason, this report should be considered a pioneering effort to put together all the required elements in a single coherent framework.

scholarly journals Effects of Microwave Treatment in Immersed Conditions on the Mechanical Properties of Jute Yarn

Fibers ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 40
Author(s):  
Felicia Syrén ◽  
Joel Peterson ◽  
Nawar Kadi
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Glass Fibers ◽  
Microwave Treatment ◽  
Environmental Benefits ◽  
Treatment Result ◽  
Bast Fiber ◽  
Fiber Properties ◽  
Yarn Thickness ◽  
Jute Yarn

The versatile bast fiber jute has environmental benefits compared to glass fibers. However, for jute to be used in a composite, the fiber properties need to be altered. This study aims to improve the mechanical properties of jute yarn to make it more suitable for technical applications as a composite. To alter its mechanical properties, jute yarn was immersed in water during microwave treatment. The time and power of the microwave settings differed between runs. Two states of the yarn were tested: fastened and un-fastened. Tensile testing was used at the yarn and fiber level, followed by Fourier-transform infrared spectroscopy (FTIR) and microscopy. The treatment result demonstrated the ability to increase the elongation of the jute yarn by 70%. The tenacity was also increased by 34% in the fastened state and 20% in the un-fastened state. FTIR showed that no change in the molecular structure occurred. The treatments resulted in a change of yarn thickness depending on the state of the yarn. The results indicate that microwave treatment can be used to make jute more suitable for technical applications depending on the microwave treatment parameters.

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