scholarly journals Effect of bitumen emulsion on mechanical performance of cold asphalt mixtures

2014 ◽  
Vol 12 (2) ◽  
pp. 195-205
Author(s):  
Miomir Miljkovic
Keyword(s):  
Mechanical Performance ◽  
Asphalt Mixtures ◽  
Continuous Change ◽  
Bitumen Emulsion ◽  
Term Basis ◽  
Innovative Material ◽  
Indirect Tensile ◽  
Fracture Performance ◽  
Pavement Construction

Implementation of innovative material and evaluation concepts in pavement construction industry is important to reduce the negative environmental impacts. The objective of this paper is to review the recent scientific developments in characterising the effect of bitumen emulsion properties on the performance of cold asphalt mixtures. The experimental approach was based on the indirect tensile testing of the standardised bitumen emulsion mortar specimens. The major finding is that there is a continuous change in mechanical properties and the mode of fracture on the long-term basis. However, the ratios of the considered fracture performance-related parameters indicated that the change in the mode of fracture from ductile to brittle is not that direct, and the reason for this could be in the relation between the development of the adhesion and the residual binder viscosity. As a step towards fundamental understanding of the contribution of adhesion, further research should be focused on the interaction between cement hydration, binder droplets, and emulsifier.

scholarly journals Comparing the Field and Laboratory Curing Behaviour of Cold Recycled Asphalt Mixtures for Binder Courses

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4697
Author(s):  
Gilda Ferrotti ◽  
Andrea Grilli ◽  
Chiara Mignini ◽  
Andrea Graziani
Keyword(s):  
Mechanical Performance ◽  
Complex Modulus ◽  
Material Design ◽  
Asphalt Mixtures ◽  
Laboratory Simulation ◽  
Curing Time ◽  
Recycled Asphalt ◽  
Air Voids ◽  
Indirect Tensile

The cold recycling of reclaimed asphalt (RA) for the rehabilitation of end-of-life pavements is becoming very common. Cold recycled asphalt mixtures (CRAMs) are characterised by a curing time, required to reach the material design mechanical performance. Since the laboratory simulation of the long-term field curing is not yet a standardised procedure, a CRAM was laid as binder course in a full-scale trial section that was monitored for more than two years. The comparison between field curing and oven-curing in laboratory at 40 °C was performed by carrying out indirect tensile stiffness modulus (ITSM), indirect tensile strength (ITS) and complex modulus tests, as well as measurements of the air voids content. The evolution of the ITSM as a function of the curing time (field/oven-curing) was obtained for both gyratory specimens and cores taken from the trial section at different time periods. Results showed that the material stiffness development can be accelerated with a small effect on its long-term value if oven-curing is applied a few days/weeks after compaction. A linear relationship was found between the ITS measured on the cores and their air voids content. Finally, the complex modulus tests confirmed that CRAMs provide an intermediate behaviour between asphalt concrete mixtures and cement-bound mixtures.

scholarly journals Effect of Aging on the Properties of Asphalt and Asphalt Mixtures

2015 ◽  
Vol 19 (2) ◽  
pp. 89
Author(s):  
Carlos Hernando Higuera Sandoval ◽  
Xiomara Vanessa Camargo Amaya ◽  
Edwin Alexander Suárez Molano
Keyword(s):  
Tensile Test ◽  
Dynamic Modulus ◽  
Work Values ◽  
Asphalt Mixtures ◽  
Indirect Tensile Test ◽  
Aged Asphalt ◽  
Indirect Tensile ◽  
The Stability

This article presents the results of the analysis of the effect of aging on the properties of asphalt and asphalt mixtures. The objective of this study was to compare the properties of the original asphalt and aged asphalt and the dynamic modulus of asphalt mixtures. The long-term aging was simulated by using Pressure Asphalt Vessel (PAV). Marshall and RAMCODES methodologies were used to determine the formula of work; values of dynamic modulus of designed mixtures were obtained by the indirect tensile test, using the Nottingham Asphalt Tester (NAT). The results showed an increase in the rigidity of the aged asphalt. Also, an increase of the stability and a decreased flow in the mixtures made with this type of binder was found. The dynamic modulus values of the mixtures containing aged asphalt showed an increase up to three times compared with those elaborated with original asphalt mixtures.

scholarly journals Recycling of Waste Materials Using Bitumen Emulsion for Road Pavement Stabilized Base Courses: a Laboratory Investigation

2021 ◽  
Vol 1203 (2) ◽  
pp. 022111
Author(s):  
Nicola Baldo ◽  
Matteo Miani ◽  
Fabio Rondinella ◽  
Marco Pasetto
Keyword(s):  
Tensile Strength ◽  
Laboratory Investigation ◽  
Environmental Sustainability ◽  
Mechanical Performance ◽  
Steel Slag ◽  
Indirect Tensile Strength ◽  
Waste Materials ◽  
Stiffness Modulus ◽  
Bitumen Emulsion ◽  
Indirect Tensile

Abstract The valorisation and reuse of waste materials can enhance the environmental sustainability of road constructions, especially by means of cold recycling techniques, which, moreover, allow to reduce polluting emissions in atmosphere. Among the various technological approaches, the use of bitumen emulsion to stabilize waste materials is very common, especially in case of reclaimed asphalt pavement (RAP) aggregates. However, even other types of waste materials could be considered using a Cold Central Plant Recycling (CCPR) approach. The paper discusses the main results of a laboratory investigation aimed to evaluate the mechanical performance of bitumen emulsion stabilized mixtures for road pavements base courses, prepared with RAP, steel slag, coal ash and glass wastes, used with various percentages. In a first step of the laboratory study, both physical and toxicological properties of each waste material have been investigated, in order to assess their environmental compatibility. Subsequently, an extensive mechanical analysis of the bitumen emulsion stabilized mixtures has been carried out in the laboratory, in terms of indirect tensile strength, indirect tensile stiffness modulus at three temperatures (10°C, 25°C, 40°C) and repeated load axial tests at 30°C. The moisture resistance of the mixes has been also investigated by means of indirect tensile strength tests carried out on soaked specimens. Very good results have been observed, depending on the mix composition: indirect tensile strength at 25 °C on dry specimens up to 0.52 MPa and stiffness modulus up to 4,056 MPa (at 25 °C, for a rise time equal to 124 ms). Therefore, it has been verified that the waste materials considered in the study can be successfully reused to completely substitute conventional aggregates in bitumen emulsion stabilized mixtures for road pavements base courses.

scholarly journals Influence of Antistripping Additives and Rejuvenators on Healing Performance of Moisture-Damaged HMA

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Dae-Wook Park ◽  
Tam Minh Phan ◽  
Yeong-Min Kim
Keyword(s):  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Moisture Resistance ◽  
Three Point Bending ◽  
Indirect Tensile ◽  
Damage Healing ◽  
Aged Binder

This study aims to evaluate the effect of different rejuvenators and antistripping agents on the healing performance of hot mix asphalt (HMA). Two damage HMA series (e.g., moisture damage and aged damage) were subjected to either induction or microwave heating. A PG64-22 virgin and aged binder were used and modified with several additives. Three long-term aged binders (e.g., PAV5, PAV15, and PAV20) were conducted by pressure aging vessel (PAV) test. The moisture damage series fabricating with a new binder was further categorized into four different freeze-thaw (FT) cycles (e.g., 0FT, 1FT, 3FT, and 5FT). Also, the aged series was fabricated with three different aged binders. A total of eight damage-healing cycles were applied to all asphalt mixtures, examined by the three-point bending test. The moisture resistance of modified asphalt mixture was examined by indirect tensile strength test. Overall, asphalt mixtures modified with either antistripping additives or rejuvenators not only obtained higher moisture resistance but also gained better healing performance under moisture damage. In addition, the study showed a probable correlation between moisture damage and long-term aging in terms of healing performance, such as PAV15 and 3FT cycles and PAV20 and 5FT cycles.

scholarly journals Evaluation of Asphalt Mixtures Containing Metallic Fibers from Recycled Tires to Promote Crack-Healing

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5731
Author(s):  
Alvaro González ◽  
José Norambuena-Contreras ◽  
Lily Poulikakos ◽  
María José Varela ◽  
Jonathan Valderrama ◽  
...  
Keyword(s):  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Fiber Content ◽  
Crack Healing ◽  
Electrically Conductive ◽  
Air Voids ◽  
Indirect Tensile ◽  
Increasing Temperature ◽  
Metallic Fibers

This paper reports part of an international research project with the long-term aim of developing more sustainable asphalt mixture with crack-healing properties by the addition of recycled metallic waste from industrial sources. Specifically, this article presents an evaluation of the physical, thermophysical, and mechanical properties of asphalt mixtures with metallic fiber obtained from recycled tires for crack-healing purposes. Detailed results on the crack-healing of asphalt mixtures will be reported in a second article. Results showed a small reduction on the bulk density and increase in the air voids content was quantified with increasing fiber contents. The experimental results showed that mixing and compaction was more difficult for higher fiber contents due to less space for the bitumen to freely flow and fill the voids of the mixtures. Computed tomography (CT) results allowed to identify clustering and orientation of the fibers. The samples were electrically conductive, and the electrical resistivity decreased with the increase of the fiber content. Fiber content had a direct effect on the indirect tensile stiffness modulus (ITSM) and strength (ITS) that decreased with increasing temperature for mixtures and with increase in fiber content. However, the indirect tensile strength ratio (ITSR) was within acceptable limits. In short, results indicate that fibers from recycled tires have a potential for use within asphalt mixtures to promote crack-healing.

Socioeconomic Challenges faced by Basin’s People in India

Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 296-304
Author(s):  
Biplab Tripathy ◽  
Tanmoy Mondal
Keyword(s):  
River Basin ◽  
High Tide ◽  
North East ◽  
The People ◽  
Term Basis ◽  
Major River ◽  
River Ganga ◽  
Basin Region ◽  
Basin Area

India is a subcontinent, there huge no of people lived in river basin area. In India there more or less 80% of people directly or indirectly depend on River. Ganga, Brahamputra in North and North East and Mahanadi, Govabori, Krishna, Kaveri, Narmoda, Tapti, Mahi in South are the major river basin in India. There each year due to flood and high tide lots of people are suffered in river basin region in India. These problems destroy the socio economic peace and hope of the people in river basin. There peoples are continuously suffered by lots of difficulties in sort or in long term basis. Few basin regions are always in high alert at the time of monsoon seasons. Sometime due to over migration from basin area, it becomes empty and creates an ultimate loss of resources in India and causes a dis-balance situation in this area.

A Review on Recent Trends in Nanomaterials and Nanocomposites for Environmental Applications

2020 ◽  
Vol 16 ◽  
Author(s):  
Kannappan Panchamoorthy Gopinath ◽  
Malolan Rajagopal ◽  
Abhishek Krishnan ◽  
Shweta Kolathur Sreerama
Keyword(s):  
Environmental Pollution ◽  
Environmental Remediation ◽  
Carbon Capture ◽  
Potential Applications ◽  
Important Challenge ◽  
Term Basis ◽  
Short And Long Term ◽  
Recent Trends ◽  
Water And Soil Pollution

Background: Depletion and contamination of environmental resources such as water, air and soil caused by human activities is an increasingly important challenge faced around the world. The consequences of environmental pollution are felt acutely by all living beings, both on a short and long-term basis, thereby making methods of remediation of environmental pollution an urgent requirement. Objectives: The objective of this review is to dissect the complications caused by environmental degradation, highlight advancements in the field of nanotechnology and to scrutinize its applications in environmental remediation. Furthermore, the review aims to concisely explain the merits and drawbacks of nanotechnology compared to existing methods. Conclusion: The current and potential applications of nanomaterials and nanocomposites in the prevention, control and reduction of air, water and soil pollution and the mechanisms involved have been elucidated, as have their various merits and demerits. The applications of nanotechnology in the fields of carbon capture and agriculture have also received attention in this review.

Preventative Child Welfare Services in Victoria

1988 ◽  
Vol 13 (1) ◽  
pp. 10-14
Author(s):  
Brian Mitchell
Keyword(s):  
Child Welfare ◽  
Fundamental Principle ◽  
Child Welfare Services ◽  
Welfare Services ◽  
Term Basis ◽  
Voluntary Agencies

The idea of prevention in child welfare is not new. The prevention of substitute placement of children whether on a temporary or long-term basis has been a fundamental principle of child welfare we have held to for many years in Victoria.However, it is only in the last decade that this principle is actually being carried out in practice by a number of voluntary agencies. For many children placement is still commonly used as a solution it is easier to place a child than to promote change within many multi-deficit families.

scholarly journals Impact of Prolonged Exposure of Eleven Years to Hot Seawater on the Degradation of a Thermoset Composite

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2154
Author(s):  
Amir Hussain Idrisi ◽  
Abdel-Hamid I. Mourad ◽  
Muhammad M. Sherif
Keyword(s):  
Exposure Time ◽  
Prolonged Exposure ◽  
Mechanical Performance ◽  
Matrix Cracking ◽  
Pull Out ◽  
Strength Based ◽  
Different Temperatures ◽  
River Line ◽  
Composite Samples

This paper presents a long-term experimental investigation of E-glass/epoxy composites’ durability exposed to seawater at different temperatures. The thermoset composite samples were exposed to 23 °C, 45 °C and 65 °C seawater for a prolonged exposure time of 11 years. The mechanical performance as a function of exposure time was evaluated and a strength-based technique was used to assess the durability of the composites. The experimental results revealed that the tensile strength of E-glass/epoxy composite was reduced by 8.2%, 29.7%, and 54.4% after immersion in seawater for 11 years at 23 °C, 45 °C, and 65 °C, respectively. The prolonged immersion in seawater resulted in the plasticization and swelling in the composite. This accelerated the rate of debonding between the fibers and matrix. The failure analysis was conducted to investigate the failure mode of the samples. SEM micrographs illustrated a correlation between the fiber/matrix debonding, potholing, fiber pull-out, river line marks and matrix cracking with deterioration in the tensile characteristics of the thermoset composite.

scholarly journals Electrospun PCL Patches with Controlled Fiber Morphology and Mechanical Performance for Skin Moisturization via Long-Term Release of Hemp Oil for Atopic Dermatitis

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Sara Metwally ◽  
Daniel P. Ura ◽  
Zuzanna J. Krysiak ◽  
Łukasz Kaniuk ◽  
Piotr K. Szewczyk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atopic Dermatitis ◽  
Mechanical Performance ◽  
Antibacterial Properties ◽  
Skin Condition ◽  
Fiber Morphology ◽  
Suitable Material ◽  
Hemp Oil ◽  
Skin Moisture

Atopic dermatitis (AD) is a chronic, inflammatory skin condition, caused by wide genetic, environmental, or immunologic factors. AD is very common in children but can occur at any age. The lack of long-term treatments forces the development of new strategies for skin regeneration. Polycaprolactone (PCL) is a well-developed, tissue-compatible biomaterial showing also good mechanical properties. In our study, we designed the electrospun PCL patches with controlled architecture and topography for long-term release in time. Hemp oil shows anti-inflammatory and antibacterial properties, increasing also the skin moisture without clogging the pores. It can be used as an alternative cure for patients that do not respond to traditional treatments. In the study, we tested the mechanical properties of PCL fibers, and the hemp oil spreading together with the release in time measured on skin model and human skin. The PCL membranes are suitable material as patches or bandages, characterized by good mechanical properties and high permeability. Importantly, PCL patches showed release of hemp oil up to 55% within 6 h, increasing also the skin moisture up to 25%. Our results confirmed that electrospun PCL patches are great material as oil carriers indicating a high potential to be used as skin patches for AD skin treatment.

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