A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Free Draining Base Materials Properties
The importance of providing a positive drainage system and removing free water from pavement structures has long been recognized. Inadequate drainage of the pavement structures has been identified as one of the primary causes of pavement distress. In the last few years, Oregon has started designing and constructing permeable bases in both flexible and rigid pavements. Two types of permeable bases have been used: one is asphalt treated permeable material (ATPM) base and the other is open-graded aggregate base. The desirable characteristics (permeability and resilient modulus) of both materials have not been determined. In addition, construction with the existing open-graded aggregate gradation revealed that the material was less stable and would ravel easily under construction traffic. Because of this ravelling, compaction was poor, the grade was difficult to control, and the open graded aggregate materials did not provide a suitable surface for paving. The project established the desirable materials properties (permeability and resilient modulus) for the two types of free-draining base materials and establishes a more stable gradation for the open-graded aggregate base. Appropriate layer and drainage coefficients for use in the AASHTO design of permeable base sections are also determined. For comparison, a dense-graded aggregate material is also investigated. The project consisted primarily of a laboratory investigation. Pavement cores of the asphalt treated permeable base and samples of aggregate materials were tested in the laboratory for permeability and resilient modulus. The permeability was determined using both constant and falling head test procedures. The laboratory study indicated that the current Oregon ATPM has a sufficient drainage capability and the resilient modulus of the material is typical of other states' findings. A modified open-graded aggregate gradation is proposed. The proposed aggregate gradation has a higher permeability and a higher resilient modulus than the existing gradation.
Free Draining Base Materials Properties
The importance of providing a positive drainage system and removing free water from pavement structures has long been recognized. Inadequate drainage of the pavement structures has been identified as one of the primary causes of pavement distress. In the last few years, Oregon has started designing and constructing permeable bases in both flexible and rigid pavements. Two types of permeable bases have been used: one is asphalt treated permeable material (ATPM) base and the other is open-graded aggregate base. The desirable characteristics (permeability and resilient modulus) of both materials have not been determined. In addition, construction with the existing open-graded aggregate gradation revealed that the material was less stable and would ravel easily under construction traffic. Because of this ravelling, compaction was poor, the grade was difficult to control, and the open graded aggregate materials did not provide a suitable surface for paving. The project established the desirable materials properties (permeability and resilient modulus) for the two types of free-draining base materials and establishes a more stable gradation for the open-graded aggregate base. Appropriate layer and drainage coefficients for use in the AASHTO design of permeable base sections are also determined. For comparison, a dense-graded aggregate material is also investigated. The project consisted primarily of a laboratory investigation. Pavement cores of the asphalt treated permeable base and samples of aggregate materials were tested in the laboratory for permeability and resilient modulus. The permeability was determined using both constant and falling head test procedures. The laboratory study indicated that the current Oregon ATPM has a sufficient drainage capability and the resilient modulus of the material is typical of other states' findings. A modified open-graded aggregate gradation is proposed. The proposed aggregate gradation has a higher permeability and a higher resilient modulus than the existing gradation.
Free Draining Base Materials Properties
H. Zhou (author) / L. Moore (author) / J. Huddleston (author) / J. Gower (author)
1992
92 pages
Report
No indication
English
Determination of Free-Draining Base Materials Properties
| British Library Online Contents | 1993
| European Patent Office | 2017