Sewage Sludge as Raw-Material in Asphalt Mixtures

The aim of this study is to assess the volumetric and mechanical behavior of concrete asphalt mixtures, using natural sludge as a partial substitute for the tiny aggregate and calcined sludge as filler. This assessment was performed based on technical and environmental parameters, using laboratory tests obeying current Brazilian norms, according to international standards. The addition of natural sludge to the mixtures has increased stability, increased air voids contents of the mixtures. The addition has compromised mixture adhesiveness. With respect to the addition of calcined sludge to the mixtures, the mixtures with calcined sludge displayed the same behavior as those with cement. It was observed decrease in empty space volume of the mixtures and consequent increase in empty space-bitumen relation and increased stability. The mixture addition of natural sludge that has the best mechanical and volumetric performance is the one with 7.5% of natural sludge in the granulometric composition of the mixture. The mixture with 1% of calcined sludge had the best volumetric and mechanical performance.

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Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures

Applied Sciences ◽

10.3390/app12010490 ◽

2022 ◽

Vol 12 (1) ◽

pp. 490

Author(s):

Caroline Moura ◽

Lucas Nascimento ◽

Carlos Loureiro ◽

Mafalda Rodrigues ◽

Joel Oliveira ◽

...

Keyword(s):

Circular Economy ◽

Mechanical Performance ◽

Permanent Deformation ◽

Steel Slag ◽

Cost Effective ◽

Asphalt Mixtures ◽

Raw Material ◽

Water Sensitivity ◽

Natural Aggregates ◽

And Performance

Steel slag is a byproduct generated as waste during the steelmaking process and can be considered a cost-effective and environmentally acceptable alternative to replace natural aggregates. Using steel slag aggregates (SSA) to produce asphalt mixtures promotes sustainability and circular economy principles by using an industrial byproduct as a raw material. Thus, this work mainly aims to design more sustainable asphalt mixtures with high amounts of SSA that fit the circular economy expectations. This work developed two asphalt mixtures with SSA for surface (AC 14 surf) and binder/base (AC 20 bin/base) courses. Initially, the excellent wearing and polishing resistance of SSA and their good affinity with bitumen demonstrated the potential of this byproduct to be used in asphalt mixtures. Then, when analyzing the influence of using two different SSA incorporation rates (50% and a percentage close to 100%) in both asphalt mixtures, it was concluded that the use of SSA should be limited to 75% to avoid excessive air void contents and durability problems. The importance of considering the different particle densities of SSA and natural aggregates was highlighted during the mix design by defining a relationship between an effective and equivalent binder content. Finally, the mechanical performance of AC 14 and AC 20 with 75% SSA incorporation was compared to identical conventional mixtures produced with natural granite aggregates. The results obtained showed that the asphalt mixtures with 75% SSA have some workability problems due to the rough and porous surface of SSA. However, they present an excellent water sensitivity and permanent deformation resistance, surpassing the performance of the conventional asphalt mixtures.

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Evaluation of Moisture Susceptibility for Asphalt Mixtures

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.361-363.1563 ◽

2013 ◽

Vol 361-363 ◽

pp. 1563-1566

Author(s):

Chuan Yi Zhuang ◽

Ya Li Ye ◽

Yan Zhou

Keyword(s):

Mechanical Performance ◽

Water Immersion ◽

Asphalt Mixture ◽

Temperature Stability ◽

Asphalt Mixtures ◽

Hot Water ◽

High Temperature Stability ◽

Air Voids ◽

Freeze Thaw ◽

Hot Water Immersion

Types of asphalt mixture with different gradations and air voids were designed. Tests on their indirect tensile strength, compressive strength and resilient modulus of compression under single axle compressing were taken to study the effects of two forms of water immersion (hot water immersion and freeze-thaw split test) on asphalt mixtures mechanical performance and high temperature stability. Test results point out that water immersion decreased asphalt mixtures performance seriously and the effect of freeze-thaw split tests on asphalt mixtures performance is far stronger than that of hot water immersion. Asphalt mixtures performance is related with its gradation and percent air voids. Asphalt mixtures with different gradation are different in their percent air voids, suitable gradation can form framework and filling action obviously, so to yield mixture with suitable percent air voids and good water stability.

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

Materials ◽

10.3390/ma13214697 ◽

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.

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Challenges of Media Education Standards in Georgia

Journal of Education in Black Sea Region ◽

10.31578/jebs.v2i2.47 ◽

2017 ◽

Vol 2 (2) ◽

Author(s):

Marine Vekua

Keyword(s):

Working Conditions ◽

Teaching Methods ◽

International Standards ◽

The Other ◽

Historical Background ◽

Journalism Education ◽

Education Standards ◽

Modern Media ◽

The One ◽

The Right

The main goal of this research is to determine whether the journalism education of the leading media schools inGeorgia is adequate to modern media market’s demands and challenges. The right answer to this main questionwas found after analyzing Georgian media market’s demands, on the one hand, and, on the other hand, differentaspects of journalism education in Georgia: the historical background, development trends, evaluation ofeducational programs and curricula designs, reflection of international standards in teaching methods, studyingand working conditions.

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Microstructure and mechanical property improvement of dissimilar metal joints for TC4 Ti alloy to Nitinol NiTi alloy by laser welding

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7935 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Yan Zhang ◽

DeShui Yu ◽

JianPing Zhou ◽

DaQian Sun ◽

HongMei Li

Keyword(s):

Tensile Strength ◽

Laser Welding ◽

Mechanical Performance ◽

Niti Alloy ◽

Welding Process ◽

Ti Alloy ◽

The One ◽

Fusion Weld ◽

Welding Processes ◽

Cu Interlayer

Abstract To avoid the formation of Ti-Ni intermetallics in a joint, three laser welding processes for Ti alloy–NiTi alloy joints were introduced. Sample A was formed while a laser acted at the Ti alloy–NiTi alloy interface, and the joint fractured along the weld centre line immediately after welding without filler metal. Sample B was formed while the laser acted on a Cu interlayer. The average tensile strength of sample B was 216 MPa. Sample C was formed while the laser acted 1.2 mm on the Ti alloy side. The one-pass welding process involved the creation of a joint with one fusion weld and one diffusion weld separated by the remaining unmelted Ti alloy. The mechanical performance of sample C was determined by the diffusion weld formed at the Ti alloy–NiTi alloy interface with a tensile strength of 256 MPa.

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

Remote Sensing ◽

10.3390/rs13132613 ◽

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.

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Crushed Bricks: Demolition Waste as a Sustainable Raw Material for Geopolymers

Sustainability ◽

10.3390/su13147572 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7572

Author(s):

Gigliola D’Angelo ◽

Marina Fumo ◽

Mercedes del Rio Merino ◽

Ilaria Capasso ◽

Assunta Campanile ◽

...

Keyword(s):

Energy Consumption ◽

Building Materials ◽

Mechanical Performance ◽

Raw Materials ◽

Construction Material ◽

Raw Material ◽

The European Union ◽

Total Energy Consumption ◽

Demolition Waste ◽

Crushed Brick

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.

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Russian experience in assessing informal employment indicators and their compliance with SDG indicators

Statistical Journal of the IAOS ◽

10.3233/sji-190602 ◽

2020 ◽

pp. 1-18

Author(s):

Elena Zarova ◽

Dr Konstantin Laykam ◽

Elvira Dubravskaya ◽

Sergey Musikhin

Keyword(s):

Sustainable Development ◽

Sustainable Development Goals ◽

International Standards ◽

Informal Employment ◽

Formal Sector ◽

The Sustainable Development ◽

Development Goals ◽

The Russian Federation ◽

The One ◽

Main Components

This article describes on the one hand statistical methods for assessing informal employment based on the requirements as set by international standards. On the other hand it describes the potential of integrating various data sources to generate informal employment statistics. With as example official statistics of the Russian Federation, the authors show the features of applying the requirements of international standards. Methods are proposed for assessing informal employment in the formal sector of the economy, i.e. in enterprises that submit employment reports to the National Statistical Office. This phenomenon appears in the employment situation of many countries. However, there is no uniformity between countries in how they evaluate the application of the international standards in such assessment exercises. A theoretical model of informal employment is developed and validated based on statistical data published by international organizations. The validation focuses on assessing the causal relationships between informal employment indicators and the main components of the sustainable development goals. This analysis contributes to coordinated decisions on regulating informal employment and ensuring the achievement of the Sustainable Development Goals (SDGs).

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Possibilities of the Development of Edible Insect-Based Foods in Europe

Foods ◽

10.3390/foods10040766 ◽

2021 ◽

Vol 10 (4) ◽

pp. 766

Author(s):

Magdalena Skotnicka ◽

Kaja Karwowska ◽

Filip Kłobukowski ◽

Aleksandra Borkowska ◽

Magdalena Pieszko

Keyword(s):

Material Processing ◽

Functional Food ◽

The Other ◽

Raw Material ◽

Edible Insects ◽

Mineral Salts ◽

Edible Insect ◽

Alternative Protein ◽

The World ◽

The One

All over the world, a large proportion of the population consume insects as part of their diet. In Western countries, however, the consumption of insects is perceived as a negative phenomenon. The consumption of insects worldwide can be considered in two ways: on the one hand, as a source of protein in countries affected by hunger, while, on the other, as an alternative protein in highly-developed regions, in response to the need for implementing policies of sustainable development. This review focused on both the regulations concerning the production and marketing of insects in Europe and the characteristics of edible insects that are most likely to establish a presence on the European market. The paper indicates numerous advantages of the consumption of insects, not only as a valuable source of protein but also as a raw material rich in valuable fatty acids, vitamins, and mineral salts. Attention was paid to the functional properties of proteins derived from insects, and to the possibility for using them in the production of functional food. The study also addresses the hazards which undoubtedly contribute to the mistrust and lowered acceptance of European consumers and points to the potential gaps in the knowledge concerning the breeding conditions, raw material processing and health safety. This set of analyzed data allows us to look optimistically at the possibilities for the development of edible insect-based foods, particularly in Europe.

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Investigation of an Electrostatic Discharge Protective Biodegradable Packaging Foam in the Logistic Chain

Logistics & sustainable transport ◽

10.1515/jlst-2015-0004 ◽

2014 ◽

Vol 5 (1) ◽

pp. 25-33 ◽

Cited By ~ 1

Author(s):

Ákos Mojzes ◽

Barnabás Tóth ◽

Péter Csavajda

Keyword(s):

Electrostatic Discharge ◽

Technological Development ◽

Environmental Parameters ◽

Thermoplastic Starch ◽

Vital Role ◽

Packaging Materials ◽

Negative Effects ◽

Packaging System ◽

Product Packaging ◽

The One

Abstract Since the beginning of the 20th century, logistics has undergone a huge technological development, which has, however, resulted in many negative effects as well. The industry, particularly in the packaging industry has been a massive waste producer, although recently it has forced the use of new materials and it started to focus on environmentally friendly technologies. During the transportation of finished and semi-finished Electrostatic Discharge (ESD) sensitive products, the product packaging system has a vital role. These kind of packaging materials must be suitable to both logistic (protection against mechanical and environmental stresses) and special ESD protection requirements. During the transportation of printed-circuit electronic products, ESD defense is then of primary significance. However there is a huge disadvantage for the use of various shield bags. Namely, this kind of associated packaging is particularly pollutant, it causes a lot of inconvenience in the form of waste. In order to rule out these materials from the packaging system, new innovative solutions have to be found. The investigated TPS (thermoplastic starch biodegradable foam) is subjected to a validation, a long process to certify that this material unites properties of two types of packaging materials at the same time. On the one hand, this packaging foam has to meet the requirements product defense. On the other hand, the material must be anti-static under the logistic stress effects. In case it is found suitable, it can be an alternative of the conventional materials. In this article, we investigate the ESD characteristic of TPS foam. As this material sensitive for environmental parameters during transportation, we make the relevant Surface Resistance (Rs) tests on different temperature and humidity conditions. Based on result, the decision of the application can be done, as an ESD packaging material.

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