VALIDATION OF JAPAN’S DESIGN METHOD OF PAVEMENT THAT RELATES ITS THICKNESS INDEX, WHEEL LOAD AND SUBGRADE <i>CBR</i>

Rut，referred to as a common damage of asphalt pavement ，is still a knotty problem to pavement researchers. Many reasons could cause rut, among which heavy duty, improper pavement structural combination design are two principal factors. As a result, three pavement structures and seven types of asphalt mixtures were used to evaluate the rutting resistance performance of different structural combinations. At first, through Marshall design method, the properties of asphalt mixtures were obtained such as gradation, asphalt content and so on. Based on the comparison of gradations and anti-rutting additives, the single layer rut was tested by wheel tracking test. Then, in order to consider influence of pavement structural design on pavement rut, six types of structure combinations under identical heavy duty condition were designed to perform rutting test. It shows that anti-rutting gradation and anti-rutting additives can improve rutting resistance performance of single layer. Also, a proper structural design could provide a better bearing capacity of wheel load even for heavy duty. It is better to integrate the anti-rutting gradation and anti-rutting additives into structural design. In this paper the results provide some new insight into the relationship between rutting resistance and mixture gradation, anti-rutting additives, heavy duty and structural combination. The consideration of these factors will give a better pavement design.

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Reliability-based conversion of a structural design code for railway prestressed concrete sleepers

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409711418754 ◽

2011 ◽

Vol 226 (2) ◽

pp. 155-173 ◽

Cited By ~ 36

Author(s):

A M Remennikov ◽

M H Murray ◽

S Kaewunruen

Keyword(s):

Dynamic Response ◽

Prestressed Concrete ◽

Design Method ◽

Railway Track ◽

Material Strength ◽

Dynamic Resistance ◽

Limit States ◽

Wheel Load ◽

Head Surface ◽

Current Design

Ballasted railway track is very suitable for heavy-rail networks because of its many superior advantages in design, construction, short- and long-term maintenance, sustainability, and life cycle cost. An important part of the railway track system, which distributes the wheel load to the formation, is the railway sleeper. Improved knowledge has raised concerns about design techniques for prestressed concrete (PC) sleepers. Most current design codes for these rely on allowable stresses and material strength reductions. However, premature cracking of PC sleepers has been found in railway tracks. The major cause of cracking is the infrequent but high-magnitude wheel loads produced by the small percentage of irregular wheels or rail-head surface defects; both these are crudely accounted for in the allowable stress design method by a single load factor. The current design philosophy, outlined in Australian Standard AS1085.14, is based on the assessment of permissible stresses resulting from quasi-static wheel loads and essentially the static response of PC sleepers. To shift the conventional methodology to a more rational design method that involves a more realistic dynamic response of PC sleepers and performance-based design methodology, comprehensive studies of the loading conditions, the dynamic response, and the dynamic resistance of PC sleepers have been conducted. This collaborative research between several Australian universities has addressed such important issues as the spectrum and the amplitudes of dynamic forces applied to the railway track, evaluation of the reserve capacity of typical PC sleepers designed to AS 1085.14, and the development of a new limit states design concept. This article presents the results of the extensive analytical and experimental investigations aimed at predicting wheel impact loads at different return periods (based on field data from impact detectors), together with an experimental investigation of the ultimate impact resistance of PC sleepers required by the limit states design approach. It highlights the reliability approach and rationales associated with the development of limit states and presents guidelines pertaining to conversion of AS 1085.14 to a limit states design format. The reliability concept provides design flexibility and broadens the design principle, so that any operational condition could be catered for optimally in the design.

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Simplified Generalized California Bearing Ratio Pavement Design Equation

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196153900106 ◽

1996 ◽

Vol 1539 (1) ◽

pp. 44-50 ◽

Cited By ~ 2

Author(s):

Michael Divinsky ◽

Ilan Ishai ◽

Moshe Livneh

Keyword(s):

Statistical Analysis ◽

Design Method ◽

Probabilistic Approach ◽

Pavement Design ◽

California Bearing Ratio ◽

Design Parameters ◽

Design Equation ◽

Suggested Model ◽

Load Curve ◽

Wheel Load

The probabilistic approach to pavement design and evaluation requires estimation of the diversity associated with each design parameter. Results and conclusions should be based on statistical analysis with wide application of mathematical statistics and theory of reliability methods. Consequently, statistical analysis of the California bearing ratio design equation was performed, and a new generalized design equation suggested. This equation provides a simplified and rapid pavement design prediction using the common basic design parameters. The suggested model and equation provide at least the same and, possibly, greater accuracy than the current deterministic pavement design method provides. At the same time, they eliminate the need to determine the equivalent single-wheel load curve for each loading and wheel configuration, depending instead on the number of wheels in the assembly only. It is believed that the suggested model and equation also provide an appropriate step toward the application of stochastic pavement design methods.

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Linear Tracking Performance Tests on Full-Depth Asphalt Pavement

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1570-05 ◽

1997 ◽

Vol 1570 (1) ◽

pp. 39-47 ◽

Cited By ~ 5

Author(s):

J. Groenendijk ◽

C. H. Vogelzang ◽

A. Miradi ◽

A. A. A. Molenaar ◽

L. J. M. Dohmen

Keyword(s):

Design Method ◽

Asphalt Pavement ◽

Heavy Traffic ◽

Design Criterion ◽

Public Works ◽

Materials Testing ◽

Wheel Load ◽

The Road ◽

Almost All ◽

Tracking Device

A 0.15-m-thick gravel asphalt concrete (AC) pavement on a sand subgrade was loaded with 4 million repetitions of a 75-kN super-single wheel load using the linear tracking device (LINTRACK) heavy-traffic simulator. Frequent measurements were carried out, including asphalt strain, temperature, rutting, cracking, and falling weight deflectometer measurements, to investigate the performance of full-depth asphalt pavements. The subsequent data analysis indicated that the life of the tested asphalt pavement, according to the Dutch fatigue-design criterion (halving the asphalt stiffness), was 2 to 4 times longer than predictions based on the pavement-design method of the Road and Hydraulic Engineering Division (RHED) of the Dutch Ministry of Transport, Public Works and Water Management. Thus, this method does not give an unsafe design. The analysis also indicated that halving of the asphalt stiffness, implying structural distress, occurred before any cracking was visible at the pavement surface. Almost all visible cracking occurring later in this test pavement consisted of surface cracking instead of structural cracking. Therefore, the structural distress did not grow upward to form the visible cracks at the surface, but the latter formed independently. The same was observed on Dutch highways, which are much thicker. These conclusions are based on only one test section, although supplemented with extensive materials testing, and verification with other tests is necessary.

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