Relationship between creep time dependent index and Paris Law parameters for bituminous mixtures

Published ArticleBituminous mixtures undergo cracking, either top-down or bottom-up, as a consequence of the repeated application of traffic loads, thermal cycling or a combination of the two mechanisms. Cracking is considered as one of the major distress modes in asphalt pavements. This study presents a method to characterise crack resistance of asphaltic mixtures containing waste materials using a semi-circular bending (SCB) fracture test. Three different bituminous mixtures containing incinerator bottom ash waste and one control mix, containing limestone, were tested under cycling SCB loading conditions at 5°C and the results were interpreted using Paris Law. The same mixtures were also tested under controlled stress creep conditions at the same temperature. This paper examines the link between the time dependent index from creep tests with the n parameter from the Paris Law model, based on visco-elastic continuum damage mechanics analysis and linear elastic fracture mechanics principles

Sustainable approach to upgrade low volume roads in Petrusville

Published ArticleResearch undertaken in Petrusville and Philipstown was to illustrate how nonconventional materials performed as a sub-base. Roads investigated in this research paper were classified as light or low volume roads where the daily traffic equalled to 100 vehicles per day. Main objectives was to achieve a reduction in the overall life cycle cost, vehicle operating cost and the depletion of nonrenewable resources for the roads. The outcome the road authorities and the different stakeholders wanted to achieve was that non-conventional materials can replace good quality road construction materials if the approach is cost effective and sustainable in the long term

South Africa Class F Fly Ash for roads : physical and chemical analysis

Published ArticleFly Ash is a by-product at thermal power stations, also otherwise known as residues of fine particles that rise with flue gases. An industrial by-product may be inferior to the traditional materials used construction applications, but, the lower the cost of these inferior materials make it an attractive alternative if adequate performance can be achieved. The objective of this study is to evaluate the chemical and physical effectiveness of self-cementing fly ashes derived from thermal power stations for construction applications with combined standards. Using laboratory testing specimens, suitable types of Fly Ashes namely: Kendal Dump Ash, Durapozz and Pozzfill, were tested to the required standards to evaluate the potential properties. All three Fly Ashes have been classified as a Class F Fly Ash, which requires a cementing agent for reactions to take place and for early strength gains in the early stages of the reaction processes. The Fly Ashes conformed to the combination of standards and have shown that the proper reactions will take place and will continue over period of time. The use of fly ash is accepted worldwide due to saving in cement, consuming industrial waste and making durable materials, especially due to improvement in the quality fly ash products

POSSIBLE IMPACTS OF ICT BASED DEMAND-RESPONSIVE PUBLIC TRANSPORTATION SCHEMES IN THE FREE STATE

Published Conference ProceedingsReliability and accessibility of public transportation are major concerns. ICT based demand responsive schemes can be the ultimate solution to these problems. Even though Demand Responsive Transportation solutions have always been conventional for cabs to meet individual traveller’s needs, they have not been used for buses and mini-bus taxis in the Free State. Therefore, they can be considered to provide reliable and flexible transportation to meet the public’s momentary transportation needs at affordable rates using taxis and buses. Current accessibility problems like long walking distance to bus stops and long waiting times can be solved using demand responsive schemes and cheaper demand based minibus taxi or bus services would reduce the use of expensive cabs. This would reduce public transportation reliability, accessibility, affordability and efficiency problems, but might not have the same impact on operators and public transportation users. The benefits they might have on public transportation users could lead to immediate or long-term consequences for the operators. This paper aims at evaluating the possible impacts of using ICT based technologies and applications for demand responsive public transportation in the Free State province and how they may impact public transportation operators and users in terms of dead mileage, travel times, intensity of demand in different areas and acceptance of these schemes by the public and operators

Numerical Simulation of Pavement Life Deterioration: Tree-Roots’ Effects

Conference ProceedingsFlexible pavement is usually designed to last for at least 20 years, however sometimes the first failure is formed after the first year of use. This failure has been associated with; overloading of the structure, use of poor materials, drainage problem and inadequate pavement thickness, and poor compaction; without considering presence of tree-root in pavement layers. However, with the numerous advantages of finite element model (FEM) in designing pavement structure and coupled with the fact that it’s a non-destructive tool, it makes its use sustainable. Therefore, this study focuses on investigating the impact of tree-roots on design life of flexible pavement using FEM. Results of the study show that tree-roots within any layer, and most especially within the subgrade layer, have a great effect on its bearing capacity. Moreover, it was found that this effect decreases subgrade life by approximately 13 - 67 %, with respect to the root thickness and this consequently decreases the entire pavement life

Dual Induction of New Microbial Secondary Metabolites by Fungal Bacterial Co-cultivation

We thank the College of Physical Sciences, University of Aberdeen, for provision of infrastructure and facilities in the Marine Biodiscovery Centre. We acknowledge the receipt of funding from the European Union’s Seventh Programme for Research, Technological Development and Demonstration under Grant Agreement No. 312184 (PharmaSea). MR thanks School of Science and Sport, University of the West of Scotland for providing the open-access fees required for the publication.Peer reviewedPublisher PD

Internet of Things based Framework for Public Transportation Fleet Management in Free State, South Africa

ArticleThestudybasedonbestframeworkdesignusinginternetofthings(IoT).IoTreferstoanestablishedcommunicationbetweenidentifiedthingsthroughinternet;likesensors,tags,WirelessSensorNetwork(WSN),Radio-FrequencyIdentification(RFID),GPS.(Kopetz,2011),(Atzoriet.al.,2010)

POSSIBLE CHALLENGES OF INTEGRATING ICTS INTO THE PUBLIC TRANSPORTATION SYSTEM IN THE FREE STATE

ArticleInformationCommunicationTechnologies(ICTs)arebecomingahugepartofthepublictransportationsystemsallovertheworld.ICTsinpublictransportation,alsoknownasIntelligentTransportationSystemsarerelativelynewinSouthAfricaandevenunheardofinsomepartsoftheFreeStateprovinceofSouthAfrica.Thesetechnologies,whichincludeelectronicfarepayments,VariableMessageSigns,AutomaticVehicleLocation,CCTVsurveillance,mobileapplicationsandtheinternetareyettobeimplementedintheFreeStateprovince.TheuptakeofICTsolutionsinpublictransportationinothercountrieswasbasedonassumptionsthatitwillimprovepublictransportationthroughthesetechnologicaldevelopments.Itwasthoughtthattechnologywillimproveservicedelivery,thereforereducingtheexistingbarrierstowardspublictransportationandresultinginthepublicbeingmorepatriotictopublictransportationsystems(NelsonandMulley,2013).ChallengesarelikelytobeencounteredwhenintegratingICTsintothepublictransportationatallstagesoftheprocess,fromplanninghowtousethesolutionstothefunctionalstageofthefullyintegratedpublictransportationsystem.Therefore,beforedeployingthesetechnologies,thesepossiblechallengesshouldbeconsidered,takingintoconsiderationthecurrentstateofpublictransportation,itsmanagement,commuters,operatorsanddrivers

Possible Challenges of Integrating ICTs into the Public Transportation System in the Free State Province, South Africa

Published ArticleThere is need for ICT in the Free State public transportation system and for its implementation to be successful, information is needed on the needs of the various stakeholders and assessment of whether those needs are possible to fulfill using ICT solutions. The conventional and traditional poor quality transportation system needs to be improved. ICTs have shown to be the ultimate solution to most public transport problems. For successful ICT integration, implementation and operation of these ICT solutions to improve the public transportation system challenges may be encountered which has to be addressed. This study investigates the challenges which are likely to be faced by the different stakeholders at the different levels of the integration process

A space-time pseudospectral discretization method for solving diffusion optimal control problems with two-sided fractional derivatives

We propose a direct numerical method for the solution of an optimal control problem governed by a two-side space-fractional diffusion equation. The presented method contains two main steps. In the first step, the space variable is discretized by using the Jacobi-Gauss pseudospectral discretization and, in this way, the original problem is transformed into a classical integer-order optimal control problem. The main challenge, which we faced in this step, is to derive the left and right fractional differentiation matrices. In this respect, novel techniques for derivation of these matrices are presented. In the second step, the Legendre-Gauss-Radau pseudospectral method is employed. With these two steps, the original problem is converted into a convex quadratic optimization problem, which can be solved efficiently by available methods. Our approach can be easily implemented and extended to cover fractional optimal control problems with state constraints. Five test examples are provided to demonstrate the efficiency and validity of the presented method. The results show that our method reaches the solutions with good accuracy and a low CPU time.Comment: This is a preprint of a paper whose final and definite form is with 'Journal of Vibration and Control', available from [http://journals.sagepub.com/home/jvc]. Submitted 02-June-2018; Revised 03-Sept-2018; Accepted 12-Oct-201