Spelling suggestions: "subject:"unpaved loads"" "subject:"concaved loads""
1 |
Hierarquização para orientar a manutenção de rodovias não-pavimentadas / To guide the maintenance of non-paved roadsOliveira, Mário José Garrido de 12 December 2005 (has links)
O trabalho mostra que a distribuição de qualidade de viagem do ponto de vista de quem usa rodovias, o Sistema de Posicionamento Global (GPS) e o Sistema de Informação Geográfica (SIG) podem contribuir para aperfeiçoar o manuseio de informação para hierarquizar necessidades de intervenção, e orientar manutenção de rodovias não-pavimentadas acessível a cidades pequenas do Brasil. Para isso foram estudadas escalas de classificação geradas a partir de análise sobre distribuições de variáveis que descrevem defeitos de rodovias não-pavimentadas em função de opiniões emitidas por habitantes e produtores rurais. O GPS de navegação foi usado para determinar coordenadas de pontos de rodovias. O SIG usado é brasileiro e de domínio público. A argumentação foi obtida em estudo de caso sobre as rodovias de Nova Europa, estado de São Paulo, Brasil. / This dissertation shows that the distribution of trip quality from the point of view of highway users, the Global Positioning System (GPS) and the system of Geographical Information System (GIS) can contribute with information accessible to brazilian small cities administrators to classify the hierarchy of intervention necessities to guide the maintenance of non-paved roads. Scales of classification from analysis on distributions of variables were studied describing non-paved roads defects obtained from the study of the opinions of inhabitants and rural producers. The GPS of navigation was used to determine coordinates of highway points. The GIS used is a brazilian product of public domain. The argument was gotten in a case study on highways from the city of Nova Europa, state of São Paulo, Brazil.
|
2 |
Hierarquização para orientar a manutenção de rodovias não-pavimentadas / To guide the maintenance of non-paved roadsMário José Garrido de Oliveira 12 December 2005 (has links)
O trabalho mostra que a distribuição de qualidade de viagem do ponto de vista de quem usa rodovias, o Sistema de Posicionamento Global (GPS) e o Sistema de Informação Geográfica (SIG) podem contribuir para aperfeiçoar o manuseio de informação para hierarquizar necessidades de intervenção, e orientar manutenção de rodovias não-pavimentadas acessível a cidades pequenas do Brasil. Para isso foram estudadas escalas de classificação geradas a partir de análise sobre distribuições de variáveis que descrevem defeitos de rodovias não-pavimentadas em função de opiniões emitidas por habitantes e produtores rurais. O GPS de navegação foi usado para determinar coordenadas de pontos de rodovias. O SIG usado é brasileiro e de domínio público. A argumentação foi obtida em estudo de caso sobre as rodovias de Nova Europa, estado de São Paulo, Brasil. / This dissertation shows that the distribution of trip quality from the point of view of highway users, the Global Positioning System (GPS) and the system of Geographical Information System (GIS) can contribute with information accessible to brazilian small cities administrators to classify the hierarchy of intervention necessities to guide the maintenance of non-paved roads. Scales of classification from analysis on distributions of variables were studied describing non-paved roads defects obtained from the study of the opinions of inhabitants and rural producers. The GPS of navigation was used to determine coordinates of highway points. The GIS used is a brazilian product of public domain. The argument was gotten in a case study on highways from the city of Nova Europa, state of São Paulo, Brazil.
|
3 |
Effect Of Recycled Cement Concrete Content On Rutting Behavior Of Asphalt ConcreteGul, Waqar Ahmed Waqar 01 August 2008 (has links) (PDF)
Disposed waste materials remained from demolished buildings have been an
environmental problem especially for developing countries. Recycled Cement
Concrete (RCC) is one of the abundant components of waste materials that
include quality aggregates. Use of RCC in asphalt concrete pavements is
economically a feasible option as it not only helps in recycling waste materials but
also preserves natural resources by fulfilling the demand for quality aggregate in
pavement constructions. However, due to variability in RCC characteristics, a
detailed evaluation of its effect on asphalt concrete performance is required.
In this study, effect of RCC content on rutting potential of asphalt concrete is
investigated using laboratory prepared specimens. Rutting susceptibility of the
specimens is determined using repeated creep tests performed in the uniaxial
stress mode. Because of the aspect ratio requirements for the repeated creep test,
the standard Marshall mix design procedures were modified based on the energy
concept by changing the compactor device and the applied design number of
blows. The modified specimens were tested to determine a number of parameters
that can describe the rutting behavior of the tested mixes. The findings indicate
that slope constant and flow number give relatively stronger relationships with
rutting behavior as compared to the other rutting parameters. While increasing the RCC content yields improved rutting performance for coarse graded specimens, it
dramatically reduces the performance for fine graded specimens.
|
4 |
Evaluation Of Resilient Modulus Estimation Methods For Asphalt Mixtures Based On Laboratory MeasurementsDemirci, Canser 01 May 2010 (has links) (PDF)
Resilient modulus is a property for bound and unbound pavement materials characterizing the elastic behavior of materials under dynamic repeated loading. Resilient modulus is an important design parameter for pavement structures because it represents the structural strength of pavement layers through which the thickness design is based on. In Turkey, the layer thickness design is performed using resilient modulus determined empirically from various published sources. Determining a layer modulus using empirical methods causes inaccurate design solutions, which directly affects the structural performance and the overall cost of pavement construction. In this study, the resilient moduli of bituminous mixtures are measured in the laboratory by the indirect tensile test procedure for eight asphalt concrete samples according to NCHRP and ASTM procedures. The measured moduli of samples based on the two procedures are compared with the predicted values calculated from various empirical methods using aggregate and binder properties. An evaluation of each estimation method is presented on the basis of its accuracy level. The results show that the Witczak predictive equation produces the closest estimation to the modulus of samples for both laboratory measurement methods.
|
5 |
Parametric Study On Selected Mathematical Models For Dynamic Creep Behavior Of Asphalt ConcreteOzturk, Hande Isik 01 December 2007 (has links) (PDF)
Rut formation has long been recognized as a distress mechanism in flexible pavements. One of the causes of rut formation in flexible pavements is permanent deformation of uppermost asphalt concrete layers due to repeatedly applied traffic loading. The long term permanent deformation of asphalt concrete under repeated load is commonly called as dynamic creep. The primary objective of this thesis is to examine dynamic creep behavior of asphalt concrete specimens tested in laboratory and also study some suitable mathematical models for representing dynamic creep behavior.
In this study, a set of uniaxial repeated load creep tests were performed on standard Marshall specimens prepared at three different bitumen contents. The effects of bitumen content and test condition parameters on dynamic creep behavior are examined. Among several mathematical creep models suggested by researchers, two well known models and a model proposed by the author are selected for representing the laboratory creep behavior. For each of these models, the interactions of the model parameters with varying bitumen content and test conditions are studied to detect probable definite trends, and to evaluate whether some relations for the model parameters as functions of bitumen content and test conditions can be developed or not.
The results of analyses showed that all three mathematical models used in this study are successful in representing the laboratory dynamic creep behavior of asphalt concrete. The Power Model which has only two parameters is found to be the most stable and suitable model for parametric study among the three selected models. More consistent and definite interactions are observed between the parameters of this model and test conditions. However, within the scope of this study, no relations could be developed for the parameters of selected models as functions of bitumen content and test conditions because of limited test data.
|
6 |
Investigation Of Low Temperature Cracking In Asphalt Concrete PavementQadir, Adnan 01 December 2010 (has links) (PDF)
In this study, low temperature cracking of asphalt concrete is investigated based on a laboratory experimental program including the design variables of aggregate type, gradation, asphalt content, binder grading, binder modification, and the experimental variables of cooling rate, and specimen size. The design of experiment is proposed according to the fractional factorial design principles to reduce the required number of test specimens. Mix designs are performed according to the Superpave mix design guidelines using materials obtained from the Turkish General Directorate of High-ways. In the course of this study, a test setup for thermal stress restrained specimen test for asphalt concrete is developed and used successfully to test a number of as-phalt concrete beam specimens. The same setup is also used for measuring the glass transition temperatures to obtain various thermo-volumetric properties of mixtures. Statistical methods are used to identify the effect of experimental variables on frac-ture strength, fracture temperature and other dependent variables obtained from the testing program. Statistical models are also developed to predict the fracture strength, fracture temperature and other thermo-volumetric properties of mixtures. Results of analyses show that aggregate type, binder modification, and asphalt content significantly affect both the fracture strength and fracture temperature of asphalt concrete. While the glass transition temperature is affected by only aggregate type, coefficients of contraction before and after the glass transition temperature are not influenced by any of the experimental variables. The results of this study provide an important basis to prevent low temperature cracking in asphalt concrete pavements.
|
Page generated in 0.0564 seconds