Effect of drainage in unbound aggregate bases on flexible pavement performance

  • 48 Pages
  • 1.70 MB
  • English
Louisiana Transportation Research Center , Baton Rouge, La
Statementby Mingjiang Tao, Murad Abu-Farsakh
ContributionsAbu-Farsakh, Murad Y. (Murad Yusuf), 1961-, Louisiana. Dept. of Transportation and Development, Louisiana Transportation Research Center, United States. Federal Highway Administration
LC ClassificationsTE215 .T36 2008
The Physical Object
Paginationxiii, 48 p. :
ID Numbers
Open LibraryOL24443167M
LC Control Number2010474451

Details Effect of drainage in unbound aggregate bases on flexible pavement performance PDF

Abstract: It has been well demonstrated that a positive subsurface drainage is beneficial in enhancing pavement performance and thus extending pavement service life.

Typical permeable base materials include asphalt/cement-treated, open-graded. PDF | On Jul 8,Mingjiang Tao and others published Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance | Find, read and.

Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance. Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance [Final report] CBR and DCP values may not be good properties to differentiate performance of unbound aggregate with different gradations; and (3) an optimum gradation is identified, which outperforms current Louisiana class II base gradation in terms of both Author: Mingjiang Tao, Murad Y.

Abu-Farsakh. effect of drainage in unbound aggregate bases on flexible pavement performance - Free download as PDF File .pdf), Text File .txt) or read online for free. Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance by Mingjiang Tao, Ph.D., P.E. Murad Abu-Farsakh, Ph.D., P.E.

Louisiana Transportation Research Center Gourrier Avenue Baton Rouge, LA LTRC Project No. GT State Project No conducted for Louisiana Department of Transportation and Development. If drainage is one of the primary functions of your flexible pavement unbound aggregate base/subbase layer, what approach is adopted by your agency to facilitate the drainability of dense-graded base courses.

� Limiting the maximum allowable percent fines (material passing sieve No. ) � Increasing the maximum aggregate size �. Finally, based on the investigation results, some recommendations are provided to design and construct adequate drainage system and apply proper maintenance in order to enhance pavement.

Based on recent research from California, permeable base layers may strip and become clogged with fines thus weakening the overall pavement structure.

If unbound, they may also be less stable than a dense-graded aggregate. A method of conveying the removed water away from the pavement structure. Unbound aggregates are the most common type of materials used for construction of the base layer of flexible pavements in Iran and worldwide.

Due to the lack of binder, the performance of the. Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance Starting Date: 3/1/ Duration: 18 months Completion Date: 8/31/ Funding: State Principal Investigator: Mingjiang Tao, Ph.D., Research Associate, LTRC Co-Principal Investigator: Murad Abu-Farsakh, Ph.D., P.E., Assistant Professor/GERL Manager, LTRC LTRC Contacts.

coarse gradation, and optimum fine gradation. The permeability of unbound March Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance Introduction LTRC Proj. GT ~ State Proj. Scope Principal Investigators: Mingjiang Tao, Ph.D., P.E.

Murad Abu-Farsakh, Ph.D., P.E. LTRC Contact. Untreated Aggregate Base Design full depth HMA for the traffic and subgrade condition.

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Out of this, consider 2-in as surface course and the remaining as base course. Design the pavement with the same traffic and subgrade condition using the selected emulsified base. Compute the thickness of emulsified base by taking the surface course. Higher moisture affects aggregate base layer resilient modulus, which leads to premature failure in pavements and reduced service life.

This paper presents an approach for quantifying the effect of infiltration through surface cracks on flexible pavement performance.

From the GAP transportation conference proceedings: In “Design and Construction of Bases and Subbases for Concrete Pavement Performance,” Shreenath Rao, Hesham Abdualla, and Thomas Yu, P.E. use a mix of data and case studies to show the impact that the base/subbase has on increasing or decreasing the overall concrete pavement performance.

The case studies included in this paper. TRB’s National Cooperative Highway Research Program (NCHRP) Report Effects of Subsurface Drainage on Pavement Performance: Analysis of the SPS-1 and SPS-2 Field Sections explores the effects of subsurface drainage features on pavement performance through a program of inspection and testing of the subsurface drainage features present in the Long-Term Pavement Performance SPS-1 (flexible.

drain out from the base and sub-base, thus avoiding saturation of base and subgrade soils. This paper deals with the analysis of the impact of subsurface drainage on pavement system performance.

The requirement of effective subsurface drainage for pavement performance is also discussed. New Flexible Pavement Design Strategies – Developing the Initial Trial Design The MEPDG flexible pavement design procedure allows a wide variety of HMA mixtures, aggregate base layers, and foundation improvements.

Specific types of flexible pavement. The objectives of the study were to evaluate the effectiveness of the flexible pavement drainage system based on the current specification (Superpave mixture design) as used by INDOT, and to then determine if such systems are necessary for current flexible pavement cross-sections, given contemporary materials and construction specifications.

base course, typically consisting of m to m of unbound coarse aggregate. An optional subbase layer, which generally involves lower quality crushed aggregate, can be placed under the base course in order to reduce costs or to minimize capillary action under the pavement.

fig. 1 Cross-section of flexible pavement system (Muench ).

Description Effect of drainage in unbound aggregate bases on flexible pavement performance EPUB

The design of a flexible pavement with a permeable layer must consider both of these key attributes to pro-vide satisfactory performance.

• For a conventional AC pavement with an unbound dense aggregate base, the addition of edgedrains ap-peared to reduce fatigue cracking, but not rutting. An earlier study in Minnesota showed that sections of. The contributions of the unbound aggregate base and granular subbase layers to pavement support and performance were evaluated from a mechanistic-empirical pavement design perspective by incorporating in the analyses cross-anisotropic stress-dependent layer modulus characterizations linked to two different aggregate quality levels (high and low).

bases and subbases for concrete pavements as well as the effects on performance. Grading: pavements than for flexible pavements. Flexible Pavement Base Subgrade. Wheel Load. Rigid Pavement Base Subgrade. Wheel Load. men Rigid Pavement The base layer may consist of unbound aggregate, bitumen, or cement bound aggregate.

The bound. reduction of non-uniformity (variations) of pavement support was proposed. The performance of each type of base design is ranked using FWD data together with the proposed criteria.

Chapter 3 presents the sensitivity study on the effects of granular base on predicted pavement performance using. The effects of particle size distribution and nonlinear stress dependency of sandy subgrade modulus to the pavement responses were analyzed using the finite-element program TTI-PAVE.

A horizontal to vertical modulus ratio of approximately was assumed for the unbound aggregate base to account for its anisotropic stiffness behavior (Kim ). Realistic pavement stresses induced by moving wheel loads were examined in the unbound aggregate base and subbase layers, and the significant effects of rotation of principal stress axes were.

Based on current pavement design criteria, the effect of F-T cycles on the performance of asphalt pavements has not been taken in to consideration in the stage of design and construction.

An additional option arise from mixing with natural aggregates to build the sub-base layer. This paper shows the first results of a research activity undertaken on a test track specifically constructed with the aim to analyze the effect on pavement performance of a sub-base layer mixture with 50% of natural aggregates and 50% of RAP.

However, the potential exists for water to enter the unbound aggregate base layer from the ATPB layer through the prime coat that separates them. The stiffness, strength, and performance of unbound aggregate layers are largely influenced by moisture content.

The assessment of the performance of two types of flexible pavement cross section, one. Highways provide the arteries of modern society. The interaction of road, rail and other transport infrastructure with the ground is unusually intimate, and thus needs to be well-understood to provide economic and reliable infrastructure for society.

Challenges include not only the design of new infrastructure (often on problematic ground), but inc3/5(1). effective alternative for pavement drainage. Calculations based on time-to drain approach indicate: adequate infiltration rates to handle significant storm events. drain the geocomposite layer.

drain the road even when placed beneath moderately permeable dense graded aggregate base.The longevity and performance of a pavement section depend on the characteristics of the subgrade soil. A majority of the pavements in North Texas are constructed on expansive soils. The deterioration of the pavement performance due to rutting, cracking, and differential heaving is a regular phenomenon in the regions predominantly distributed.Unbound aggregate layers are widely used in pavement base or subbase applications for both conventional flexible and rigid pavements.

Hydraulic properties, i.e., hydraulic conductivity and moisture-suction characteristics, of these layers dictate their effectiveness in providing adequate drainage, which is essential for long-term pavement performance.