[PDF] Aggregate Quality Requirements For Pavements eBook

Author : American Association of State Highway and Transportation Officials
Publisher : AASHTO
Page : 622 pages
File Size : 12,93 MB
Release : 1993
Category : Pavements
ISBN : 1560510552

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Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.

Author : Magdy Abdelrahman
Publisher :
Page : 14 pages
File Size : 42,59 MB
Release : 2010
Category : Aggregate
ISBN :

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The demand for pavement facilities that can handle increasing loads escalates the need for high quality aggregate material. While once plentiful, quality aggregate sources are starting to diminish. When aggregates are eliminated locally by resource depletion as well as land development that prohibits mining, the cost of construction can rise significantly. The cost of transporting quality aggregate materials from other places that comply with specifications can be very expensive. Coarse aggregate specifications for pavement mixtures for many states are outdated, with some sections dating back to around the 1930s. Specifications do not reflect the current level of knowledge concerning testing methodologies of desirable aggregate properties for pavement applications, especially at the local and low volume level. There is a need to evaluate the quality of aggregates based on the suitability of property-based testing requirements. A better understanding of testing requirements used to evaluate material properties can lead to a better utilization of local aggregate materials and reduce the reliance on diminishing high quality sources. This study investigates what property-based testing requirements have been established in current specifications as well as new areas of testing that need to be developed. A questionnaire of professionals defined a set of testing requirements for different pavement applications, which were then compared to the currently specified testing requirements. The results concluded that gaps exist in how professionals define quality aggregate compared to what current specifications define as quality aggregate. This creates the need for the inclusion of more property-based testing that could better characterize aggregates based on pavement performance. This type of characterization could open up the possibility of utilizing local materials that are normally rejected for lower volume applications.

Author : Ken Skorseth
Publisher :
Page : 112 pages
File Size : 32,70 MB
Release : 2000
Category : Gravel roads
ISBN :

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The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.

Author : John Pat Harris
Publisher :
Page : 51 pages
File Size : 50,26 MB
Release : 2004
Category : Aggregates (Building materials)
ISBN :

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The Texas Department of Transportation has experienced problems with inconsistent performance of the coarse aggregate fraction of hot mix asphalt pavements. This project was initiated to address problems associated with variations in hotmix coarse aggregate quality. More specifically, the researchers wanted to identify simple tests that can be performed at the aggregate quarries to assess the durability of aggregates and determine what percentage of an aggregate is poor quality. The researchers surveyed civil engineering and geological literature to identify simple tests that can identify poor performing aggregates and can be performed in the field with a minimal amount of skill. Following the identification of potential tests, the researchers visited several quarries in Texas and used these techniques to differentiate good and poor quality coarse aggregates. The researchers identified several simple tests that inspectors can perform in the field to identify poor quality aggregates, including: aggregate angularity (more rounded = poorer quality), water absorption (more absorbed = poorer quality), hardness (soft = poorer quality), and fines content (more fines = poorer quality). Things that can be done at the aggregate quarries include: constructing smaller stockpiles, selective quarrying of good rock, and utilizing a wash system to remove some of the poorer quality aggregates. The preceeding tests and quarry recommendations can be utilized by inspectors to regulate the quality of coarse aggregate used in hotmix applications.