Field Evaluation of Asphalt Mixture Skid Resistance and Its Relationship to Aggregate Characteristics PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Field Evaluation of Asphalt Mixture Skid Resistance and Its Relationship to Aggregate Characteristics PDF full book. Access full book title Field Evaluation of Asphalt Mixture Skid Resistance and Its Relationship to Aggregate Characteristics by Eyad Masad. Download full books in PDF and EPUB format.
Author: Eyad Masad
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 115
Get Book Here
Book Description
This report documents the findings from the research that was carried out as part of Phase II of TxDOT Project 0-5627. The research included measurements and analysis of mechanical and physical properties of aggregates used in surface mixes in the state of Texas. These properties were aggregate shape characteristics measured using the Aggregate Imaging System (AIMS), British Pendulum value, coarse aggregate acid insolubility, Los Angeles weight loss, Micro-Deval weight loss, and Magnesium sulfate weight loss. In addition, a database of field skid number measurements that were collected over a number of years using the skid trailer was developed. The Dynamic Friction Tester (DFT) and Circular Texture Meter (CTMeter) were used to measure friction and texture, respectively, of selected asphalt pavement sections. These data and measurements were used to carry out comprehensive statistical analyses of the influence of aggregate properties and mixture design on skid resistance value and its variability. Consequently, a method and software were developed for predicting asphalt pavement skid resistance. This method requires inputs that describe aggregate resistance to polishing, mixture gradation, and traffic. The developed software can be used to select the mixture type and aggregate source that are needed to achieve the required level of skid resistance for a given service life.
Author: Eyad Masad
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 115
Get Book Here
Book Description
This report documents the findings from the research that was carried out as part of Phase II of TxDOT Project 0-5627. The research included measurements and analysis of mechanical and physical properties of aggregates used in surface mixes in the state of Texas. These properties were aggregate shape characteristics measured using the Aggregate Imaging System (AIMS), British Pendulum value, coarse aggregate acid insolubility, Los Angeles weight loss, Micro-Deval weight loss, and Magnesium sulfate weight loss. In addition, a database of field skid number measurements that were collected over a number of years using the skid trailer was developed. The Dynamic Friction Tester (DFT) and Circular Texture Meter (CTMeter) were used to measure friction and texture, respectively, of selected asphalt pavement sections. These data and measurements were used to carry out comprehensive statistical analyses of the influence of aggregate properties and mixture design on skid resistance value and its variability. Consequently, a method and software were developed for predicting asphalt pavement skid resistance. This method requires inputs that describe aggregate resistance to polishing, mixture gradation, and traffic. The developed software can be used to select the mixture type and aggregate source that are needed to achieve the required level of skid resistance for a given service life.
Author:
Publisher: AASHTO
ISBN: 1560514280
Category : Pavements
Languages : en
Pages : 87
Get Book Here
Book Description
This report contains guidelines and recommendations for managing and designing for friction on highway pavements. The contents of this report will be of interest to highway materials, construction, pavement management, safety, design, and research engineers, as well as others concerned with the friction and related surface characteristics of highway pavements.
Author: Sand Aldagari
Publisher:
ISBN: 9781369538816
Category : Pavements, Asphalt
Languages : en
Pages : 256
Get Book Here
Book Description
Pavement skid resistance is one of the primary factors in highway safety. Pavements with adequate skid resistance reduce the number of crashes in wet conditions. The friction between pavement surface and vehicle tires is related to the macrotexture and microtexture of pavement surface. The macrotexture of asphalt pavement is dependent on aggregate gradation, while the microtexture is dependent on aggregate shape characteristics. Aggregates with angular shape and rough texture provide higher level of skid resistance compared to aggregates with smooth surface. In addition, pavement surfaces with high macrotexture provide higher skid resistance compared to those with low macrotexture. There were two main objectives of this study. The first object was to investigate and examine the surface and friction characteristics of various test sections of asphalt mixtures as well as seal coat surfaces. The test sections included different asphalt mixture types (e.g., dense graded, stone matrix asphalt, porous friction course), seal coat grades (Grade 1, Grade 2, and Grade 3), aggregate types (e.g., limestone, gravel, granite, sandstone), and the test sections were located in regions with different environmental conditions. The second objective was to develop a predictive model for skid resistance of seal coat surfaces and validate and revise an existing skid prediction model for asphalt pavements. Field testing primarily included measurements of coefficient of friction using a dynamic friction tester, pavement surface texture using a circular texture meter, and skid number using a skid trailer. The measurements were conducted on the outer lane where pavement surfaces experience significant polishing rates because most of the trucks use that lane. The resistance of aggregate to polishing and abrasion was studied using laboratory test methods. Several analytical models were developed to predict the friction and skid resistance of asphalt pavements and seal coat surfaces over their service life. These models incorporate parameters that describe aggregate resistance to abrasion and polishing, aggregate shape characteristics, aggregate gradation, and traffic level. These models were developed based on comprehensive field testing and aggregate laboratory characterization. Good correlations were found between the developed models and experimental data. The results demonstrated that aggregate and surface characteristics as well as traffic level have significant effect on skid resistance and rate of skid reduction. These models can be used during the mix design procedure to optimize the aggregate selection and aggregate gradation to produce mixtures with proper friction. In addition, these models can be incorporated in a Project Management System (PMS) at the network level to plan and program preventive maintenance activities to ensure that pavements have adequate skid resistance.
Author: Inge Hoff
Publisher: CRC Press
ISBN: 1000533336
Category : Technology & Engineering
Languages : en
Pages : 501
Get Book Here
Book Description
Innovations in Road, Railway and Airfield Bearing Capacity – Volume 1 comprises the first part of contributions to the 11th International Conference on Bearing Capacity of Roads, Railways and Airfields (2022). In anticipation of the event, it unveils state-of-the-art information and research on the latest policies, traffic loading measurements, in-situ measurements and condition surveys, functional testing, deflection measurement evaluation, structural performance prediction for pavements and tracks, new construction and rehabilitation design systems, frost affected areas, drainage and environmental effects, reinforcement, traditional and recycled materials, full scale testing and on case histories of road, railways and airfields. This edited work is intended for a global audience of road, railway and airfield engineers, researchers and consultants, as well as building and maintenance companies looking to further upgrade their practices in the field.
Author: Arash Rezaei
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The skid resistance of asphalt pavement is a major characteristic that determines the driving safety on a road, especially under wet surface conditions. Skid resistance is primarily a function of the microtexture and macrotexture of a pavement surface. Microtexture is influenced by aggregate surface characteristics and is required to disrupt the continuity of surface water film and attain frictional resistance between the tire and the pavement surface. Macrotexture is affected mostly by mixture design or aggregate gradation and contributes to skid resistance by providing drainage paths of water that can be otherwise trapped between a tire and a pavement surface. The increase in macrotexture contributes to preventing hydroplaning and improving wet frictional resistance, particularly at high speeds. While much research has been conducted in the past to identify material factors that affect skid resistance, there is still a need to develop a model for predicting asphalt pavement skid resistance as a function of mixture characteristics and traffic level. The purpose of this study was to develop such a model based on extensive laboratory experiments and field measurements involving different mixture types and aggregate sources. The model incorporates functions that describe the resistance of aggregates to polishing and aggregate size distribution. The aggregate resistance to polishing was quantified by measuring aggregate texture using the Aggregate Imaging System (AIMS) before and after polishing in the Micro-Deval device. The analysis in this dissertation demonstrates how this model can be used to design mixtures and classify aggregates that provide desirable skid resistance levels.
Author: Eyad Masad
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 209
Get Book Here
Book Description
Author: Anthony Luce
Publisher:
ISBN:
Category : Aggregate
Languages : en
Pages : 12
Get Book Here
Book Description
Aggregate properties are one of the important factors that influence the asphalt pavement skid resistance. This paper presents a detailed analysis of aggregate texture and its relationship to pavement skid resistance. A new method is developed for the evaluation of aggregate resistance to polishing. This method relies on the Micro-Deval test as the mechanism for polishing aggregates and the Aggregate Imaging System (AIMS) for quantifying the change in texture due to polishing. The results show that the Micro-Deval test is an effective method for polishing aggregates within a short time. Also, the AIMS texture analysis is able to rapidly and accurately quantify the influence of polishing on texture. The verification of the new method was achieved through measuring the skid resistance of pavements constructed using three different aggregate sources and three different aggregate gradations. The skid resistance was found to be related not only to average aggregate texture, but also to the texture distribution within an aggregate sample. The developed method can be used in models for predicting the change in asphalt pavement skid resistance as a function of aggregate texture, mixture properties, and environmental conditions.
Author: Arif Chowdhury
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 154
Get Book Here
Book Description
Pavement skid resistance is primarily a function of the surface texture, which includes both microtexture and macrotexture. Earlier, under the Texas Department of Transportation (TxDOT) Research Project 0-5627, the researchers developed a method to predict asphalt pavement skid resistance based on inputs including aggregate texture before and after polishing, gradation of asphalt mixture, and traffic levels. In this study, the researchers validated and revised the skid prediction model for asphalt pavements and developed oped a skid prediction model for seal coat surfaces. The researchers investigated and examined the surface friction characteristics of 70 test sections of asphalt mixtures and surface-treated roads in Texas. The test sections covered a wide range of mixtures and aggregate types. The researchers measured pavement macrotexture and microtexture of these sections and revised the traffic calculation. Historical skid numbers were obtained from TxDOT's Pavement Management Information System database and measured using a skid trailer. Aggregate texture and angularity was quantified using the aggregate image measurement system. Statistical methods were used to develop a prediction model for skid numbers, and the predicted values were compared to the measured ones in the field. The revised model describes the skid resistance of asphalt pavements as a function of aggregate characteristics, mixture gradation, and traffic level. The researchers incorporated aggregate angularity as an additional parameter in the model. Similarly, the researchers developed a skid prediction model for seal coat surfaces using the same parameters. A Microsoft Access--based Visual Basic desktop application was developed to automatically calculate the predicted skid numbers by incorporating the skid prediction mode ls. Using this standalone application, one can input the basic aggregate characteristics and traffic data to predict the pavement's skid resistance during its service life.
Author: Hossein B. Takallou
Publisher:
ISBN:
Category : Asphalt-rubber
Languages : en
Pages : 694
Get Book Here
Book Description
Rubber-modified asphalt pavements have been used in Sweden and the United States since the 1970's. In these applications ground recycled tire particles (1/4 inch minus) are added to a gap-graded aggregate and then mixed with hot asphalt cement. The benefits of adding rubber to the mix include increased skid resistance under icy conditions, improved flexibility and crack resistance, elimination of solid waste, and reduced traffic noise. The major disadvantage of these rubber-modified mixes is their high cost in relation to conventional asphaltic concrete pavements. This research project consisted of a laboratory study of mix properties as a function of variables such as rubber gradation and content, void content, aggregate gradation, mix process, temperature, and asphalt content. Twenty different mix combinations were evaluated for diametral modulus and fatigue at two different temperatures ( -6°C, +10°C). Also, five different mix combinations were evaluated for static creep and permanent deformation. Layered theory was used to evaluate the effects of mixture variations on pavement life. The resulting information was used to develop guidelines for use of rubber asphalt mixes in United States road systems. The findings of the field survey indicate that the rubber-modified asphalt mixture is more susceptible than the conventional mixtures to preparation and compaction problems when adverse weather or equipment problems occur. However, with adequate equipment and favorable weather conditions, the rubber-modified asphalt mixture placement is similar to conventional mixture placement. The field study also indicates that stopping distances can be reduced 20 percent for the rubber-modified pavements in icy conditions. In view of the significant reductions in wintertime stopping distances under icy or frosty road surface conditions, the use of coarse rubber in asphalt pavements should be seriously considered. This is particularly true for areas such as bridge decks, on and off freeway ramps or insulated roadway sections. The findings of the laboratory study indicate that the rubber gradation and content, aggregate gradation, and use of surcharge during sample preparation have considerable effect on modulus and fatigue life of the mix. The results of static creep and permanent deformation tests indicate that the rubber asphalt mixes had low stability and high elasticity. Also, due to greater allowable tensile strain in rubber-modified mixtures, the thickness of the modified mixture can be reduced, using a layer equivalency of 1.4 to 1.0.
Author: R. Roque
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 208
Get Book Here
Book Description
