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This thesis reports on a materials science appraisal for recycled construction materials in roadways, that supports engineering decision-making. Inconsistent performance criteria for roadway materials and the variable nature of material source have prompted the need for this research. The aim of the study is to investigate the application of a materials science appraisal to recycled construction materials for use in roadways. The investigation is undertaken through a literature review of roadways, conceptual development of the materials science appraisal methodology, and demonstration of the application of the materials science appraisal to recycled construction materials; and how this supports engineering decision-making. The literature review revealed that there are numerous and proven uses of recycled and secondary materials in roadway applications but there was a lack of necessary integration of materials into categories by material-type, which can better describe behaviour in an engineering situation. Three novel fundamental material types (ceramic, metallic, and polymeric) have been described. The conceptual development of the innovative and novel materials science appraisal, based on material-type, has defined how materials science through a systematic step-by-step procedure can be used to achieve engineering sustainability in roadways and provide support in engineering decision-making. The application of the novel concept of the materials science appraisal to recycled construction materials is shown through the essence of laboratory testing. The results from the materials science appraisal, together with sensitivity analysis, give an informed engineering decision on product choice. The appraisal is novel in that it is proposing a new theory on materials science and developed a paradigm shift in the evaluation of recycled construction materials. The appraisal overcomes the absence of materials science thinking in the field of roadway engineering. The materials science appraisal is of benefit to various stakeholders (client, consultant, supplier and contractor) as it provides a method for addressing material uncertainties. A system now exists for introducing into designs and any contract the principles of the materials science appraisal that will be of great benefit to industry.

No description available.

No description available.

Shared roadways are a cost effective method for providing bicycle facilities in areas with limited right-of-way; shared roadways have automobiles and bicycles operating in the same traveled way. However, shared roadways may negatively affect traffic operations and there is limited guidance on appropriate shared roadways implementation. This thesis has three objectives: evaluate the impact of shared roadways on automobile quality of service, compare automobile quality of service to bicycle quality of service on shared roadways, and provide guidance on the implementation of shared roadways. The author hypothesizes that shared roadways should only be implemented when automobile Level of Service (LOS), bicycle LOS, and facility safety are "acceptable." The author accomplishes the objectives by generating data using microsimulation models. The author uses microsimulation model data to evaluate automobile quality of service on shared roadways. In the evaluation of automobile quality of service, the measures of effectiveness are automobile LOS threshold (the maximum automobile flow-rate before a change in automobile LOS) and automobile average travel speed (the average travel time divided by the segment length, a space mean speed). To compare automobile and bicycle quality of service, the author uses the bicycle LOS model in NCHRP Report 616 to generate bicycle LOS thresholds (the maximum automobile flow-rate before a change in bicycle LOS). After generating bicycle LOS thresholds, the author compares the bicycle LOS thresholds to the automobile LOS thresholds. Finally, the author uses the findings of the investigations to provide guidance on the implementation of shared roadways. In this thesis, the author finds automobile quality of service on shared roadways decreases as automobile free-flow speed, automobile volume, and bicycle volume increase. For most conditions, the author finds bicycle quality of service is better than automobile quality of service on shared roadways. Bicycle quality of service is lower than automobile quality of service with increases in unsignalized access points per mile, signalized intersection crossing distance, and heavy vehicle percent. The author provides guidance on the implementation of shared roadways based upon automobile quality of service.

Doctor of Philosophy / Department of Civil Engineering / Sunanda Dissanayake / Malgorzata J. Rys / Driver workload increases on horizontal curves due to more complicated navigation compared to navigation on straight roadway sections. Although only a small portion of roadways are horizontal curve sections, approximately 25% of all fatal highway crashes occur at horizontal curve sections. According to the Fatality Analysis Reporting System (FARS) database, fatalities associated with horizontal curves were more than 25% during last years from 2008 to 2014, reinforcing that investigation of horizontal curve crashes and corresponding safety improvements are crucial study topics within the field of transportation safety. Improved safety of horizontal curve sections of rural transportation networks can contribute to reduced crash severities and frequencies. Statistical methods can be utilized to develop crash prediction models in order to estimate crashes at horizontal curves and identify contributing factors to crash occurrences, thereby correlating to the primary objectives of this research project. Primary data analysis for 221 randomly selected horizontal curves on undivided two-lane two-way highways with Poisson regression method revealed that annual average daily traffic (AADT), heavy vehicle percentage, degree of curvature, and difference between posted and advisory speeds affect crash occurrence at horizontal curves. The data, however, were relatively overdispersed, so the negative binomial (NB) regression method was utilized. Results indicated that AADT, heavy vehicle percentage, degree of curvature, and long tangent length significantly affect crash occurrence at horizontal curve sections. A new dataset consisted of geometric and traffic data of 5,334 horizontal curves on the entire state transportation network including undivided and divided highways provided by Kansas Department of Transportation (KDOT) Traffic Safety Section as well as crash data from the Kansas Crash and Analysis Reporting System (KCARS) database were used to analyze the single vehicle (SV) crashes. An R software package was used to write a code and combine required information from aforementioned databases and create the dataset for 5,334 horizontal curves on the entire state transportation network. Eighty percent of crashes including 4,267 horizontal curves were randomly selected for data analysis and remaining 20% horizontal curves (1,067 curves) were used for data validation. Since the results of the Poisson regression model showed overdispersion of crash data and many horizontal curves had zero crashes during the study period from 2010 to 2014, NB, zero-inflated Poisson (ZIP), and zero-inflated negative binomial (ZINB) methods were used for data analysis. Total number of crashes and severe crashes were analyzed with the selected methods. Results of data analysis revealed that AADT, heavy vehicle percentage, curve length, degree of curvature, posted speed, difference between posted and advisory speed, and international roughness index influenced single vehicle crashes at 4,267 randomly selected horizontal curves for data analysis. Also, AADT, degree of curvature, heavy vehicle percentage, posted speed, being a divided roadway, difference between posted and advisory speeds, and shoulder width significantly influenced severe crash occurrence at selected horizontal curves. The goodness-of-fit criteria showed that the ZINB model more accurately predicted crash numbers for all crash groups at the selected horizontal curve sections. A total of 1,067 horizontal curves were used for data validation, and the observed and predicted crashes were compared for all crash groups and data analysis methods. Results of data validation showed that ZINB models for total crashes and severe crashes more accurately predicted crashes at horizontal curves. This study also investigated the effect of speed limit change on horizontal curve crashes on K-5 highway in Leavenworth County, Kansas. A statistical t-test proved that crash data from years 2006 to 2012 showed only significant reduction in equivalent property damage only (EPDO) crash rate for adverse weather condition at 5% significance level due to speed limit reduction in June 2009. However, the changes in vehicles speeds after speed limit change and other information such as changes in surface pavement condition were not available. According to the results of data analysis for 221 selected horizontal curves on undivided two-lane highways, tangent section length significantly influenced total number of crashes. Therefore, providing more information about upcoming changes in horizontal alignment of the roadway via doubling up warning sings, using bigger sings, using materials with higher retroreflectivity, or flashing beacons were recommended for horizontal curves with long tangent section lengths and high number of crashes. Also, presence of rumble strips and wider shoulders significantly and negatively influenced severe SV crashes at horizontal curve sections; therefore, implementing rumble strips and widening shoulders for horizontal curves with high number of severe SV crashes were recommended.

Over-height trucks are not only a hazard to the over-height trucks themselves, but they pose a threat to the bridges they come into contact with, and most importantly the other drivers on the road way when a collision takes place with a low clearance structure. Therefore, there is a need for an over-height detection system that is affordable yet also reliable. At this time there exist over-height detection systems using laser and infrared beam devices however, they are expensive. This high cost makes it impossible for Department of Transportations across the nation to implement these systems at all low-clearance headroom roadways. In this research a machine vision based system is proposed to detect the height of trucks and provide a warning for over-height vehicles. The height determination will be completed using line detection and blob tracking; these two methods will be overlapped where an upper point of the truck can be compared to a lower point on the ground. These 2D coordinates will then be translated into 3D world coordinates that will provide an approximation of the truck height. If the truck is over the set height then a warning will sound. The accuracy of the test proves that the method is a reliable method of height determination, achieving a 96.59% accuracy rate for measured trucks. The method does have an error rate of 3.3%. The merit of this work is the creation of an automatic image based method which can provide height determination of trucks and is a low cost alternative to the current expensive laser and infrared detection systems.

Thesis(PhD (Civil Engineering))-- University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Bitumen based road surfacing seals and asphalt wearing courses have been used by society's Engineers "to counter the damage to the existing unsurfaced roadways by the newly developed automobile with its rubber driving wheels" since the early 1900's. Early experiments were conducted with both tar and bitumen to find a suitable material to alleviate the situation, and ongoing research has been carried out through the past century and into the new millennium, throughout the world, examining improvements, from materials used, to design and construction methods. However, there is still much to be understood, improved and refined, when considering road surfacing seal design. Pavement designers have the choice of utilizing either an asphalt (graded aggregate remanufactured with a bitumen binder and applied as a complete product) or a surfacing seal (including variations of bitumen binder sprayed onto the road surface, with the addition of single size stones, either in one or two layers of binder and aggregate, i.e. single or double seals) as a pavement wearing course. Current road surfacing seal design practice depends on empirical analysis and experience, being primarily a volumetric based assessment of bitumen application. This research project assesses South African seal design philosophy, investigates design areas where review or updating is required to accommodate changing bitumen sources and types, and traffic loading. Seal performance criteria are examined, with the development of a matrix of influences on seal performance. Using this, the need for a seal design method based on mechanistic material properties is proposed, and the prototype example of such a numerical model using finite element method is presented. To contribute further towards a performance related seal design method, the feasibility of modelling of road surfacing seals using mechanistic principles was examined. The potential of developing failure and fatigue criteria or relationships to enable assessment of the expected seal performance, with inclusion of different component material characteristics and variations, varying traffic and environmental conditions, was also examined. From assessment of literature, and understanding of the components of the seal, pavement, and influencing factors, a choice of numerical model of seal performance was made. The Finite Element Method (FEM) Analysis was selected for the purpose of modelling seal performance. The model was developed to enable examination of the interaction of individual seal components (i.e. stone and bitumen), at micro-mechanic scale. The prototype 3-dimensional numerical seal model was undertaken in 2002 and 2003 at Technical University Delft, using the CAPA research program. On the basis of the linear calculations the developed numerical prototype model is able to provide insight into seal behaviour and distinction between mechanical (seal geometry) and chemical (components) seal aspects, and insight into stress and strain development in the different seal types. Simulations of different seal, environmental and traffic scenarios are provided to demonstrate the potential of the model (excluding seal aggregate interlock and embedment effects at prototype stage). In order to provide data for the verification of the prototype numerical model, and to further contribute to the development of a performance related seal design method, performance tests were developed, with a new tool for assessment of comparative seal performance using the Model Mobile Load Simulator Accelerated Pavement Testing apparatus. The performance of each different seal binder type - Penetration grade Mumen, SBS, SBR, EVA and Bitumen Rubber - was undertaken. A methodology for the assessment of in-service seal performance was developed, and the performance of the respective seals reported. The results of this examination showed that each binder type has its unique contribution to seal performance. These new performance tests will be able to assist designers in the added determination of the fundamental binder properties on seal performance, and the seals' ability to contribute to the overall performance of the pavement. An additional comparative performance test method was developed to enable assessment of the effect of ageing and moisture, to complement the MMLS results. In summary, the performance testing has assisted in identifying the critical parameters a seal designer should consider during the design process. From this research, it is evident that the current seal design method requires further development to able designers to predict the effect of: Varying axle loads, tyre pressures and design speed; Varying characteristics of the different binders, (i.e. temperature - viscosity relationships, adhesion and visco-elastic behaviour); on the performance of seals. The major areas for suggested improvement in current seal design methods towards a performance based design method are: inclusion of variable traffic load and environmental characteristics, including temperature and moisture influences, and inclusion of mechanistic material characteristics into the design methodology. / AFRIKAANSE OPSOMMING: Bitumengebaseerde padoppervlakseellae en asfaltslytlae is sedert die 1900's deur ingenieurs gebruik as teenwig teen die skade wat die pas ontwikkelde voertuig met sy rubberwiele aan bestaande ryvlakke sonder oppervlakbehandeling aangerig het. In vroeëre eksperimente wat daarop gemik was om 'n geskikte materiaal te vind om die probleem teen te werk, is 'n kombinasie van teer en bitumen gebruik. Sedertdien word voortgesette navorsing steeds wêreldwyd gedoen om verbeterings te ondersoek, nie net ten opsigte van materiale nie maar ook ontwerp- en konstruksiemetodes. Wat die ontwerp van padoppervlakseëling betref is daar egter heelwat wat reg begryp, verbeter en verfyn moet word. Plaveiselontwerpers het die keuse om of 'n asfalt te gebruik (gegradeerde aggregaat voorafvervaardig met 'n bitumen bindmiddel en aangewend as 'n klaarproduk), of 'n oppervlakseël (een laag of twee lae [m.a.w. enkel- of dubbelseël] bitumen bindmiddel met aggregaat [enkelgrootte klippies] bygevoeg, gespuit op die padoppervlak). In die praktyk berus die ontwerp van padoppervlakseëling tans op empiriese analise en ervaring (wat hoofsaaklik 'n volumetriesgebaseerde assessering van die aanwending van bitumen is). Hierdie navorsingsprojek doen 'n waardebepaling van die Suid-Afrikaanse filosofie van seëlontwerp, en ondersoek ontwerpterreine wat hersiening of bywerking benodig om vir veranderende bitumenbronne en -tipes, asook verkeerslading, voorsiening te maak. Met die ontwikkeling van 'n matriks van die invloede op seëlprestasie is die kriteria vir seëlprestasie ondersoek. Op grond daarvan word aangevoer dat daar 'n behoefte is aan 'n seëlontwerpmetode gebaseer op die meganistiese eienskappe van materiaal, en word 'n voorbeeld van 'n numeriese modelprototipe wat die eindige-element-metode gebruik, voorgelê. Ten einde 'n verdere bydrae te lewer tot die ontwikkeling van 'n prestasiegerigte seëlontwerpmetode, is die uitvoerbaarheid van die modellering van padoppervlakseëllae gebaseer op meganistiese beginsels, ondersoek. Daar is ook ondersoek ingestel na die potensiaal vir die ontwikkeling van kriteria vir die vasstel van mislukking en vermoeidheid of verhoudinge wat die assessering van die verwagte seëlprestasie (ingesluit die verskillende kenmerke en variasies van seëlkomponentmateriaal en wisselende verkeers- en omgewingsomstandighede) moontlik kan maak. Met oorweging van die bestudeerde literatuur en 'n begrip van die komponente van seël, plaveisel en inwerkende faktore, is 'n keuse van 'n numeriese model vir seëlprestasie gemaak. Die eindige-element-metode (Finite Element Method [FEM]) is gekies as die analitiese metode vir die modellering van seëlprestasie. Die model is ontwikkel om die ondersoek van die interaksie tussen individuele seëlkomponente (klip en bitumen) op mikromeganiese skaal moontlik te maak. Die ontwikkeling van die driedimensionele, numeriese, model-seëlprototipe is tussen 2002 en 2003 by die Delft Tegniese Universiteit gedoen, met gebruikmaking van die CAPA-navorsingsprogram. Wat lineêre berekenings betref, kan die ontwikkelde numeriese modelprototipe 'n insig gee in seëlgedrag en in die onderskeid tussen aspekte van seëlgeometrie (meganies) en seëlkomponente (chemies), asook in die spanning- en vervormingsontwikkeling van die verskillende tipes seël. Simulasies van verskillende seël-, omgewings- en verkeerscenario's word voorgestel om die potensiaal van die modelprototipe te demonstreer. Met die oog daarop om data vir die verifikasie van die numeriese modelprototipe te voorsien, en om verder tot die ontwikkeling van 'n prestasiegerigte seëlontwerpmetode by te dra, is prestasietoetse, met 'n nuwe instrument vir die assessering van vergelykende seëlprestasie met behulp van die Model Mobile Load Simulator Accelerated Pavement Testing apparaat, ontwikkel. Die prestasie van elke verskillende tipe seëlbindmiddel- penetrasiegraad bitumen, SBS, SBR, EVA en bitumenrubber - is getoets. 'n Metodologie vir die assessering van die ingebruiksprestasie van seëllae is ontwikkel, en daar is verslag gedoen oor die prestasie van die verskillende seëllae. Die resultate van die ondersoek het getoon dat elke tipe bindmiddel 'n eie unieke bydrae tot die prestasie van die seël lewer. Die nuwe prestasietoets sal ontwerpers help met die bepaling van die grondliggende bindmiddeleienskappe wat by seëlprestasie ter sprake is, asook van die seël se vermoë om tot die algehele prestasie van die plaveisel by te dra. 'n Bykomende prestasievergelykingstoetsmetode vir die assessering van die effek van veroudering en vogtigheid is ontwikkel om die MMLS-resultate aan te vul. Ter opsomming, die prestasietoetsing het bygedra tot die identifisering van die kritiese parameters wat die seëlontwerper tydens die ontwerpproses in gedagte behoort te hou. Die navorsing wat gedoen is, dui daarop dat die huidige seëlontwerpmetode verder ontwikkel moet word om ontwerpers in staat te stel om die effek van die volgende te kan voorspel: Wisselende aslas, banddruk en ontwerpspoed; Verskillende kenmerke van die verskillende bindmiddels (bv. temperatuur viskositeitsverhoudinge, vashegting en viskoëlastiese gedrag). Wat huidige seëlontwerpmetodes betref, is die hoofterreine waarop 'n verbetering voorgestel word, die insluiting van veranderlike verkeerslas- en omgewingskenmerke, ingesluit die invloed van temperatuur en vogtigheid, en insluiting van meganistiese kenmerke van materiaal in die ontwerpmetodologie.

This master’s thesis deals with the analysis of stress, fatigue and the assessment of frost effects in program ALIZE as it is prescribed in norm NFP 98-086 and comparing with the regulation TP 170 Designing roadways of roads and program LayEps.

Made available in DSpace on 2016-06-02T20:00:29Z (GMT). No. of bitstreams: 1 2435.pdf: 12706646 bytes, checksum: 3e18a4a9df2eaf6a2a9277846f46dc1b (MD5) Previous issue date: 2008-12-22 / Financiadora de Estudos e Projetos / Abstract: This study presents a procedure used to determine the cost of adapting sidewalks and urban crossings through cost quantification of work needed to repair or rebuild a sidewalk segment and to adapt its crossing. The necessary work was estimated in accordance with Calçada Cidadã standards, a project elaborated by the city administration of Vitória, ES, Brazil. The sidewalk quality was assessed by determining the level of required work according to procedures and recommendations described in Ferreira & Sanches (2005). Based on these sidewalk and quality assessment models a computer program prototype was developed to assess the quality of public spaces and to determine the necessary amount of work, and its corresponding cost, to make them more accessible. In order to test the prototype and assess its viability a case study was carried out in São Carlos, SP, Brazil. It assessed the conditions of a sidewalk segment of this city s downtown streets and determined the cost of improvement work needed to make it accessible to all pedestrians. / Esta dissertação apresenta um procedimento para determinação de custos de adequação de calçadas e travessias urbanas através da quantificação dos custos dos serviços necessários a realização das obras de reparos ou da reconstrução total de um trecho de calçada, além da adequação da travessia. O levantamento dos serviços necessários foi feito utilizando-se como padrão de projeto as especificações constantes do manual do projeto Calçada Cidadã da Prefeitura Municipal de Vitória ES. A avaliação da qualidade da calçada através da determinação do seu nível de serviço foi feita segundo os procedimentos e recomendações constantes da metodologia de avaliação do nível de serviço de calçadas desenvolvida por FERREIRA E SANCHES (2005). Adotado o padrão de projeto para a calçada ideal e o modelo de avaliação da qualidade foi desenvolvido um protótipo de um programa de computador que avalia a qualidade dos espaços públicos e, a partir da avaliação da situação real, determina os serviços necessários e os seus respectivos custos para transformar este espaço em uma condição de acessibilidade melhor. Para a aferição do protótipo e da viabilidade de sua utilização foi realizado um estudo de caso na cidade de São Carlos visando avaliar as condições de um trecho de calçadas da malha viária da região central da cidade e da determinação dos custos dos serviços e obras de melhorias, necessários para tornar este trecho em condições de acessibilidades adequadas.