Author: Kurt D. Smith
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 200
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Book Description
This report presents the latest information on the design, construction and performance of portland cement concrete (PCC) overlays. It describes the four types of PCC overlays that are commonly used in highway pavement applications: bonded PCC overlays, unbonded PCC overlays, conventional whitetopping and ultra-thin whitetopping. Recommended applications, critical design elements, current overlay design methodologies, recommended construction practices, and performance highlights are described for each overlay type. Information is also provided on the selection of PCC overlays as possible rehabilitation alternatives for existing pavements. Taken together, this document addresses the current "state of the technology" of PCC overlays placed on both existing PCC pavements and on existing hot-mix asphalt pavements.
Author: Matthew T. McCormack
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Author: Kenneth H. McGhee
Publisher:
ISBN:
Category : Pavements, Concrete
Languages : en
Pages : 32
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Book Description
The report describes the Virginia Department of Transportations' first modern experience with the construction of thin-bonded Portland cement concrete overlays of existing concrete pavements and with the fast track mode of rigid paving. The study was conducted in cooperation with the Federal Highway Administration (FHWA) and used a paving mixture verified in an FHWA mobile laboratory. The study showed that the fast track mode will permit lane closure times as short as 48 hours. Of special interest was the finding that adequate strength of the bond between the old pavement and the overlay is not dependent on the use of a bonding grout.
Author: Jagat Singh Dhamrait
Publisher:
ISBN:
Category : Pavements, Concrete
Languages : en
Pages : 82
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 82
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Book Description
Author: James K. Cable
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 114
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Book Description
The Iowa ultra-thin project demonstrated the application of thin portland cement concrete overlays as a rehabilitation technique. It combined the variables of base preparation, overlay thickness, slab size, and fiber enhancement into a series of test sections over a 7.2-mile length. This report identifies the performance of the overlays in terms of deflection reduction, reduced cracking, and improved bonding between the portland cement concrete (PCC) and asphalt cement concrete (ACC) base layers. The original research project was designed to evaluate the variables over a 5-year period of time. A second project provided the opportunity to test overlay rehabilitation techniques and continue measurement of the original overlay performance for 5 additional years.
Author:
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 92
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Author: Ronald L. Hutchinson
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 100
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Book Description
"This synthesis report will be of special interest to pavement designers, materials engineers, and other seeking information on portland cement concrete overlays placed over both concrete and asphalt pavements. Detailed information is presented on design, construction, and performance of such overlays."--Avant-propos.
Author: Kenneth H. McGhee
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 52
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Book Description
Studies of efforts in Virginia to reduce the incidence of reflection cracking when portland cement concrete pavements or bases are overlayed with asphaltic concrete are reported. The methods of reflection crack reduction discussed are: (1) The use of sand as a bond breaker between portland cement concrete pavements and asphaltic overlays, (2) the use of a high tensile strength fabric as a stress relieving layer between two asphaltic concrete overlays of an old portland cement concrete pavement on a weak subbase, and (3) the use of two types of fabric as stress relieving layers between asphaltic layers and a concrete base on a very strong subbase and subgrade. The following conclusions were drawn. 1. Neither sand as a bond breaker nor high strength fabrics as stress relieving layers are effective in reducing reflection cracking where vertical joint movement (differential deflection) is a significant factor. 2. When differential deflections are greater than about 0.002 in (0.05 mm) reflection cracks form early. Such cracking is delayed for lower differential deflection but may occur as the magnitude and frequency of wheel loadings increase. 3. Both an asphalt impregnated polypropylene fabric and an unwoven, spun-bonded nylon fabric, when placed to span joints in portland cement concrete base and covered with an asphaltic concrete, overlay, are able to sustain the formation of reflection cracking in the overlaying layer without undergoing damage. 4. An asphalt impregnated polypropylene fabric spanning the joints in portland cement concrete pavements, and placed between the pavement and an asphaltic overlay, may be effective in reducing the infiltration of surface water to pavement sub-layers. There is some evidence that pavement pumping may be reduced by this method. 5. Both an asphalt impregnated polypropylene fabric and an unwoven, spun-bonded nylon fabric can delay the formation of reflection cracking. There is strong evidence, however, that such cracking is fatigue in nature and will eventually develop under the application of repetitive wheel loadings.
