Gradation Effects on Strength and Deformation Properties of High-Quality Crushed Rock Base Materials

2021 ◽  
pp. 036119812110584
Author(s):  
Ali Fouad ◽  
Rayya Hassan ◽  
Abdulrahman Mahmood
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
The State ◽  
Superior Performance ◽  
Crushed Rock ◽  
Heavy Duty ◽  
High Quality ◽  
Rock Types ◽  
Base Materials ◽  
Deformation Properties

The importance of specifying proper aggregate grading for achieving satisfactory performance in pavement applications has long been recognized. To improve the specifications for superior performance, there is a need to understand how differences in aggregate gradations within the acceptable limits may affect unbound aggregate base behavior. The effects of gradation on strength, modulus, and deformation characteristics of high-quality crushed rock base materials are described here. Two crushed rock types commonly used in constructing heavy-duty granular base layers in the State of Victoria, Australia, with three different gradations each were used in this study. The gradations used represent the lower, medium, and upper gradation limits for heavy-duty base materials specified by the State of Victoria’s road agency (VicRoads). Modified compaction tests were conducted first to determine the moisture-density relationship of all mixes. Further, California bearing ratio (CBR), unconfined compressive strength (UCS), and repeated load triaxial (RLT) tests were then performed to study the effects of different gradations on strength, resilient modulus (MR), and deformation resistance. Further, permanent deformation and MR results were modeled using two popular models for each to explain the effect of gradation on the mixtures’ characteristics. The results indicate that the gradation that provides the best characteristics varies depending on the type of material used. For the materials tested here, coarse and medium gradations provide the best mixture characteristics in relation to CBR, MR, and permanent deformation. Fine gradation mixtures of these materials have lower values of these measures but are still considered acceptable considering relevant specification for the intended application.

Design of Granular Pavements

2003 ◽  
Vol 1819 (1) ◽  
pp. 194-200 ◽  
Author(s):  
Greg Arnold ◽  
David Hughes ◽  
Andrew R. Dawson ◽  
Des Robinson
Keyword(s):  
Stress State ◽  
Design Method ◽  
Permanent Deformation ◽  
Design Criterion ◽  
Pavement Design ◽  
Performance Criteria ◽  
Crushed Rock ◽  
Long Distance ◽  
High Quality ◽  
Final Thickness

The use of high-quality quarried crushed rock aggregates is generally required to comply with current specifications for unbound granular materials (UGMs) in pavements. The source of these high-quality materials can be a long distance from the site, resulting in high transportation costs. The use of more local sources of marginal materials or the use of secondary aggregates is not allowed if they do not fully comply with existing specifications. These materials can, however, be assessed for their suitability for use in a pavement by considering performance criteria such as resistance to permanent deformation and degradation instead of relying on compliance with inflexible specifications. The final thickness of the asphalt cover and the pavement depth are governed by conventional pavement design methods, which consider the number of vehicle passes, subgrade strength, and some material property, commonly the California bearing ratio or resilient modulus. A pavement design method that includes as a design criterion an assessment of the resistance to deformation of a UGM in a pavement structure at a particular stress state is proposed. The particular stress state at which the aggregate is to perform in an acceptable way is related to the in situ stress, that is, the stress that the aggregate is anticipated to experience at a particular depth in the pavement. Because the stresses are more severe closer to the pavement surface, the aggregates should be better able to resist these stresses the closer they are laid to the surface in the pavement. This method was applied to two Northern Ireland aggregates of different quality (NI Good and NI Poor). The results showed that the NI Poor aggregate performed at an acceptable level with respect to permanent deformation, provided that a minimum of 70 mm of asphalt cover was provided. It was predicted that the NI Good material would require 60 mm of asphalt cover.

Utilization of Waste Cooking Oil (WCO) in Hot Mix Asphalt (HMA)

2020 ◽  
pp. 22-46
Author(s):  
Mastura Bujang ◽  
Wan Nur Aifa Wan Azahar ◽  
Euniza Jusli
Keyword(s):  
Chemical Treatment ◽  
Hot Mix Asphalt ◽  
Mechanical Performance ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Poor Performance ◽  
Waste Cooking Oil ◽  
Superior Performance ◽  
Dynamic Creep ◽  
Modified Binder

The use of WCO in binder modification is widely explored in response to waste management issue. A chemical treatment was proposed to reduce the acidity of the WCO that causes its poor performance. Therefore, this chapter evaluates the performance of binders modified with untreated and treated WCO. The physical and rheological tests of binder were conducted to determine optimum percentages of untreated and treated WCO in the binder. The optimum WCOs were utilized for mechanical performance evaluation of Hot Mix Asphalt (HMA) mixture through resilient modulus and dynamic creep. The test showed the failure temperature of binder modified using the treated WCO has increased to 70°C and the treated WCO mixture recorded superior performance by being less susceptible to permanent deformation as compared to the control mix. In conclusion, the chemical treatment had improved the treated WCO performance in the modified binder as asphalt paving materials.

scholarly journals Performance Evaluation of WMA Containing Re-Refined Acidic Sludge and Amorphous Poly Alpha Olefin (APAO)

2021 ◽  
Vol 13 (6) ◽  
pp. 3315
Author(s):  
Mansour Fakhri ◽  
Danial Arzjani ◽  
Pooyan Ayar ◽  
Maede Mottaghi ◽  
Nima Arzjani
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
Road Construction ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Modified Bitumen ◽  
Alternative Source ◽  
The Road ◽  
Marshall Test ◽  
Alpha Olefin

The use of waste materials has been increasingly conceived as a sustainable alternative to conventional materials in the road construction industry, as concerns have arisen from the uncontrolled exploitation of natural resources in recent years. Re-refined acidic sludge (RAS) obtained from a waste material—acidic sludge—is an alternative source for bitumen. This study’s primary purpose is to evaluate the resistance of warm mix asphalt (WMA) mixtures containing RAS and a polymeric additive against moisture damage and rutting. The modified bitumen studied in this research is a mixture of virgin bitumen 60/70, RAS (10, 20, and 30%), and amorphous poly alpha olefin (APAO) polymer. To this end, Marshall test, moisture susceptibility tests (i.e., tensile strength ratio (TSR), residual Marshall, and Texas boiling water), resilient modulus, and rutting assessment tests (i.e., dynamic creep, Marshall quotient, and Kim) were carried out. The results showed superior values for modified mixtures compared to the control mix considering the Marshall test. Moreover, the probability of a reduction in mixes’ moisture damage was proved by moisture sensitivity tests. The results showed that modified mixtures could improve asphalt mixtures’ permanent deformation resistance and its resilience modulus. Asphalt mixtures containing 20% RAS (substitute for bitumen) showed a better performance in all the experiments among the samples tested.

scholarly journals PCDRN: Progressive Cascade Deep Residual Network for Pansharpening

2020 ◽  
Vol 12 (4) ◽  
pp. 676 ◽  
Author(s):  
Yong Yang ◽  
Wei Tu ◽  
Shuying Huang ◽  
Hangyuan Lu
Keyword(s):  
High Resolution ◽  
Loss Function ◽  
High Frequency ◽  
Experimental Results ◽  
Superior Performance ◽  
Residual Network ◽  
High Quality ◽  
Convolution Approach ◽  
Visual Assessments ◽  
Coarse To Fine

Pansharpening is the process of fusing a low-resolution multispectral (LRMS) image with a high-resolution panchromatic (PAN) image. In the process of pansharpening, the LRMS image is often directly upsampled by a scale of 4, which may result in the loss of high-frequency details in the fused high-resolution multispectral (HRMS) image. To solve this problem, we put forward a novel progressive cascade deep residual network (PCDRN) with two residual subnetworks for pansharpening. The network adjusts the size of an MS image to the size of a PAN image twice and gradually fuses the LRMS image with the PAN image in a coarse-to-fine manner. To prevent an overly-smooth phenomenon and achieve high-quality fusion results, a multitask loss function is defined to train our network. Furthermore, to eliminate checkerboard artifacts in the fusion results, we employ a resize-convolution approach instead of transposed convolution for upsampling LRMS images. Experimental results on the Pléiades and WorldView-3 datasets prove that PCDRN exhibits superior performance compared to other popular pansharpening methods in terms of quantitative and visual assessments.

scholarly journals MECHANICAL PERFORMANCE OF ASPHALT MIXTURE CONTAINING CUP LUMP RUBBER

2019 ◽  
Vol 81 (6) ◽  
Author(s):  
Norfazira Mohd Azahar ◽  
Norhidayah Abdul Hassan ◽  
Ramadhansyah Putra Jaya ◽  
Hasanan Md. Nor ◽  
Mohd Khairul Idham Mohd Satar ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Modified Asphalt ◽  
Dynamic Creep ◽  
Aging Conditions ◽  
Public Work Department ◽  
Indirect Tensile

The use of cup lump rubber as an additive in asphalt binder has recently become the main interest of the paving industry. The innovation helps to increase the natural rubber consumption and stabilize the rubber price. This study evaluates the mechanical performance of cup lump rubber modified asphalt (CMA) mixture in terms of resilient modulus, dynamic creep and indirect tensile strength under aging conditions. The CMA mixture was prepared using dense-graded Marshall-designed mix and the observed behavior was compared with that of conventional mixture. From the results, both mixtures passed the volumetric properties as accordance to Malaysian Public Work Department (PWD) specification. The addition of cup lump rubber provides better resistance against permanent deformation through the enhanced properties of resilient modulus and dynamic creep. Furthermore, the resilient modulus of CMA mixture performed better under aging conditions.  

scholarly journals Experimental validation of new self-voltage balanced 9L-ANPC inverter for photovoltaic applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Jagabar Sathik ◽  
Dhafer J. Almakhles ◽  
N. Sandeep ◽  
Marif Daula Siddique
Keyword(s):  
Output Voltage ◽  
Pulse Width Modulation ◽  
Superior Performance ◽  
Modulation Scheme ◽  
Switching Frequency ◽  
Switched Capacitor ◽  
Renewable Energy Resources ◽  
High Quality ◽  
Multilevel Inverters ◽  
Blocking Voltage

AbstractMultilevel inverters play an important role in extracting the power from renewable energy resources and delivering the output voltage with high quality to the load. This paper proposes a new single-stage switched capacitor nine-level inverter, which comprises an improved T-type inverter, auxiliary switch, and switched cell unit. The proposed topology effectively reduces the DC-link capacitor voltage and exhibits superior performance over recently switched-capacitor inverter topologies in terms of the number of power components and blocking voltage of the switches. A level-shifted multilevel pulse width modulation scheme with a modified triangular carrier wave is implemented to produce a high-quality stepped output voltage waveform with low switching frequency. The proposed nine-level inverter’s effectiveness, driven by the recommended modulation technique, is experimentally verified under varying load conditions. The power loss and efficiency for the proposed nine-level inverter are thoroughly discussed with different loads.

Overview of engine oil replacement technologies in internal combustion engines of agricultural machinery

2020 ◽  
pp. 10-16
Author(s):  
S.A. Belov ◽  
I.V. Busin
Keyword(s):  
Economic Efficiency ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
The State ◽  
Engine Oil ◽  
Combustion Engines ◽  
Lubrication System ◽  
Agricultural Machinery ◽  
High Quality

The article reviews four existing technologies for replacing engine oil and a method for determining its suitability for improving economic efficiency. It is established that the oil is replaced according to the need in accordance with the defect indicators. This technology of oil condition is characterized by a more complete use of its resource. The frequency of replacement is determined by the indicators of condition, which is monitored by special sensors built into the engine lubrication system. However, the difficulty of using this technology is due to the lack of high-quality devices for monitoring the state of running engine oil in the engine.

LEGAL AND ORGANIZATIONAL PROBLEMS OF CONDUCTING COMPREHENSIVE COMMISSION INSPECTIONS OF PENAL FACILITIES ON THE SUBJECT OF ANTI-TERRORIST SECURITY STATE ASSESSMENT OF PENAL OBJECTS (TERRITORIES)

2021 ◽  
pp. 128-133
Author(s):  
Олег Игоревич Денисенко ◽  
Оганнес Давитович Мкртчян
Keyword(s):  
Law Enforcement ◽  
Russian Federation ◽  
State Assessment ◽  
The State ◽  
Organizational Level ◽  
Penal System ◽  
High Quality ◽  
The Subject ◽  
The Russian Federation ◽  
Qualitative Characteristics

В связи с увеличением числа преступлений террористической направленности разрешения требуют вопросы, связанные с обеспечением объектов (территорий) УИС инструментами антитеррористической защищенности, к которым можно отнести такие, как проведение организационно-практических мероприятий антитеррористической защиты объектов УИС, наличие соответствующей документации и ответственного должностного лица, выполнение режимных требований на объектах УИС в соответствии с законодательством РФ, а также обеспечение контроля за количественными и качественными характеристиками эксплуатируемых инженерно-технических средств охраны и надзора. Актуальность проводимого исследования обусловлена необходимостью качественной реализации в правоприменительной практике совокупности требований обеспечения мероприятий по обеспечению антитеррористической защищенности объектов (территорий) УИС с целью защиты прав и интересов всех субъектов уголовно-исполнительной системы от террористического посягательства. Авторами выявляются проблемы правового и организационного уровня при оценке состояния антитеррористической защищенности объектов УИС: формализм при проведении обследований, недостаточный уровень оснащенности объектов УИС инженерно-техническими средствами охраны и надзора, а также финансирования для удовлетворения нужд объектов УИС в части обеспечения антитеррористической защищенности. Помимо прочего упоминаются такие проблемы, как отсутствие унифицированных принципов организации деятельности комплексных комиссионных обследований, разработанных с учетом современных правоприменительных норм и запросов практики, а также обосновывается необходимость повышения компетентности сотрудников ФСИН России при проведении комплексных комиссионных обследований. In connection with the increase in the number of terrorist crimes, the resolution requires issues related to the provision of facilities (territories) of the penal system with anti-terrorist security tools, which include such as the implementation of organizational and practical measures for the anti-terrorist protection of the penal system, the availability of appropriate documentation and a responsible official, the implementation of regime requirements at the facilities of the penal system in accordance with the legislation of the Russian Federation, as well as ensuring control over the quantitative and qualitative characteristics of the operating engineering and technical means of protection and supervision. The relevance of the study is due to the fact that in law enforcement practice, a high-quality implementation of the set of requirements for ensuring the anti-terrorist protection of objects (territories) of the penal system is required so that the rights and interests of all subjects of the penal system in terms of protection from terrorist encroachment are observed. The authors identify the problems of the legal and organizational level when assessing the state of anti-terrorist security of penal facilities: formalism in conducting surveys, insufficient equipment of penal facilities with engineering and technical means of protection and supervision, as well as the level of funding to meet the needs of penal facilities in terms of ensuring anti-terrorist protection. Among other things, such problems as the lack of unified principles for organizing the activities of complex commission surveys, developed taking into account modern law enforcement norms and practice requests, are mentioned, as well as the need to improve the competence of employees of the Federal Penitentiary Service of Russia when conducting comprehensive commission surveys is substantiated.

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