Stone Interlayer Pavement Design

2000 ◽  
Vol 1709 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Masood Rasoulian ◽  
Byron Becnel ◽  
Gary Keel
Keyword(s):  
Pavement Design ◽  
Superior Performance ◽  
Base Layer ◽  
Pavement Performance ◽  
Reflective Cracking ◽  
Evaluation Period ◽  
Standard Design ◽  
Pavement Testing ◽  
Transportation Research ◽  
Cement Stabilized Base

A project was initiated to evaluate the pavement performance of an alternative pavement design, referred to here as stone interlayer or inverted pavement. The test section consisted of a 4-in. (102-mm) layer of stone base on top of 6 in. (152 mm) of in-place cement stabilized base. The control section consisted of 8.5 in. (216 mm) of cement-stabilized base layer on top of prepared subgrade (standard design). A 3.5-in. (99-mm) layer of flexible pavement was placed over both sections. The objective of the study was to evaluate reflective cracking reduction through the asphaltic pavement as well as overall pavement performance. The project took place in Acadia Parish, Route LA-97, near Jennings, Louisiana. LA-97 is considered a low-volume rural highway, with average daily traffic of 2,000 vehicles. The pavement was monitored for 7 years after construction. During the evaluation period, annual crack survey, ride, and deflection measurements were collected. Additionally, as part of the Louisiana Transportation Research Center accelerated pavement testing research program, the same pavement design was tested to failure using the Accelerated Loading Facility device. Results of the investigation showed that the stone interlayer had significantly reduced the amount of reflective cracking. The ride characteristics and structural capacity of both sections were similar during the evaluation period. Accelerated testing results also verified the superior performance of the stone interlayer pavement system. The cost analysis showed initial construction costs for the stone interlayer system may be as high as 20 percent more than standard design. However, the life of the stone interlayer pavement system is increased to almost five times that of the standard soil cement pavement as tested under accelerated loading.

Incorporation of Reliability into Mechanistic-Empirical Pavement Design

2000 ◽  
Vol 1730 (1) ◽  
pp. 73-80 ◽  
Author(s):  
David H. Timm ◽  
David E. Newcomb ◽  
Theodore V. Galambos
Keyword(s):  
Sensitivity Analysis ◽  
Monte Carlo ◽  
Reliability Analysis ◽  
Design Procedure ◽  
Fatigue Cracking ◽  
Pavement Design ◽  
Pavement Performance ◽  
Type I ◽  
Standard Design ◽  
Input Parameters

Pavement thickness design traditionally has been based on empiricism. However, mechanistic-empirical (M-E) design procedures are becoming more prevalent, and there is a current effort by AASHTO to establish a nationwide M-E standard design practice. Concurrently, an M-E design procedure for flexible pavements tailored to conditions within Minnesota has been developed and is being implemented. Regardless of the design procedure type, inherent variability associated with the design input parameters will produce variable pavement performance predictions. Consequently, for a complete design procedure, the input variability must be addressed. To account for input variability, reliability analysis was incorporated into the M-E design procedure for Minnesota. Monte Carlo simulation was chosen for reliability analysis and was incorporated into the computer pavement design tool, ROADENT. A sensitivity analysis was conducted by using ROADENT in conjunction with data collected from the Minnesota Road Research Project and the literature. The analysis demonstrated the interactions between the input parameters and showed that traffic weight variability exerts the largest influence on predicted performance variability. The sensitivity analysis also established a minimum number of Monte Carlo cycles for design (5,000) and characterized the predicted pavement performance distribution by an extreme value Type I function. Finally, design comparisons made between ROADENT, the 1993 AASHTO pavement design guide, and the existing Minnesota design methods showed that ROADENT produced comparable designs for rutting performance but was somewhat conservative for fatigue cracking.

Use of Long-Term Pavement Performance Data to Develop Traffic Defaults in Support of Mechanistic-Empirical Pavement Design Procedures

2003 ◽  
Vol 1855 (1) ◽  
pp. 176-182 ◽  
Author(s):  
Weng On Tam ◽  
Harold Von Quintus
Keyword(s):  
Pavement Design ◽  
Vehicle Classification ◽  
Pavement Performance ◽  
Traffic Data ◽  
Design Procedures ◽  
Load Spectra ◽  
State Highway ◽  
Pavement Structures ◽  
Empirical Design

Traffic data are a key element for the design and analysis of pavement structures. Automatic vehicle-classification and weigh-in-motion (WIM) data are collected by most state highway agencies for various purposes that include pavement design. Equivalent single-axle loads have had widespread use for pavement design. However, procedures being developed under NCHRP require the use of axle-load spectra. The Long-Term Pavement Performance database contains a wealth of traffic data and was selected to develop traffic defaults in support of NCHRP 1-37A as well as other mechanistic-empirical design procedures. Automated vehicle-classification data were used to develop defaults that account for the distribution of truck volumes by class. Analyses also were conducted to determine direction and lane-distribution factors. WIM data were used to develop defaults to account for the axle-weight distributions and number of axles per vehicle for each truck type. The results of these analyses led to the establishment of traffic defaults for use in mechanistic-empirical design procedures.

Evaluation of Seasonal Effects on Subgrade Soils

2003 ◽  
Vol 1821 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Andrew G. Heydinger
Keyword(s):  
Seasonal Variations ◽  
Resilient Modulus ◽  
Monitoring Program ◽  
Test Site ◽  
Pavement Design ◽  
Seasonal Effects ◽  
Pavement Performance ◽  
Climatic Effects ◽  
Subgrade Soils ◽  
Frost Penetration

One objective of the FHWA’s Long-Term Pavement Performance (LTPP) program is to determine climatic effects on pavement performance. The LTPP instrumentation program includes seasonal monitoring program (SMP) instrumentation to monitor the seasonal variations of moisture, temperature, and frost penetration. Findings from the SMP instrumentation are to be incorporated into future pavement design procedures. Data from SMP instrumentation at the Ohio Strategic Highway Research Program Test Road (US-23, Delaware County, Ohio) and other reported results were analyzed to develop empirical equations. General expressions for the seasonal variations of average daily air temperature and variations of temperature and moisture in the fine-grained subgrade soil at the test site are presented. An expression for the seasonal variation of resilient modulus was derived. Average monthly weighting factors that can be used for pavement design were computed. Other factors such as frost penetration, depth of water table, and drainage conditions are discussed.

scholarly journals Variability in Pavement Design

2015 ◽  
Vol 16 (2) ◽  
pp. 50-67 ◽  
Author(s):  
Paola Dalla Valle ◽  
Nick Thom
Keyword(s):  
Pavement Design ◽  
Pavement Performance ◽  
Design Parameters ◽  
Probability Density Distribution ◽  
Analysis And Design ◽  
The Subject ◽  
The Mean ◽  
Subgrade Modulus ◽  
Input Variables ◽  
The Uk

Abstract This paper presents the results of a review on variability of key pavement design input variables (asphalt modulus and thickness, subgrade modulus) and assesses effects on pavement performance (fatigue and deformation life). Variability is described by statistical terms such as mean and standard deviation and by its probability density distribution. The subject of reliability in pavement design has pushed many highway organisations around the world to review their design methodologies, mainly empirical, to move towards mechanistic-empirical analysis and design which provide the tools for the designer to evaluate the effect of variations in materials on pavement performance. This research has reinforced this need for understanding how the variability of design parameters affects the pavement performance. This study has only considered flexible pavements. The sites considered for the analysis, all in the UK (including Northern Ireland), were mainly motorways or major trunk roads. Pavement survey data analysed were for Lane 1, the most heavily trafficked lane. Sections 1km long were considered wherever possible. Statistical characterisation of the variation of layer thickness, asphalt stiffness and subgrade stiffness is addressed. A sensitivity analysis is then carried out to assess which parameter(s) have the greater influence on the pavement life. The research shows that, combining the effect of all the parameters considered, the maximum range of 15th and 85th percentiles (as percentages of the mean) was found to be 64% to 558% for the fatigue life and 94% to 808% for the deformation life.

scholarly journals Influence of moisture infiltration on flexible pavement cracking and optimum timing for surface seals

2020 ◽  
Vol 47 (5) ◽  
pp. 487-497 ◽  
Author(s):  
Syed Waqar Haider ◽  
Muhammad Munum Masud ◽  
Karim Chatti
Keyword(s):  
Service Life ◽  
Monitoring Program ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
Time Domain Reflectometry ◽  
Water Infiltration ◽  
Base Layer ◽  
Pavement Performance ◽  
Ann Model ◽  
Premature Failure

Moisture increase in pavement subsurface layers has a significant influence on granular material properties that affect the expected pavement performance. In situ moisture variations over time in an unbound base layer depend on water infiltration after precipitation and pavement surface conditions. Consequently, base resilient modulus (MR) is reduced, which leads to premature failure and reduced service life. This paper presents long-term pavement performance (LTPP) data analyses for quantifying the effect of moisture infiltration through surface cracking on flexible pavement performance. Subsurface moisture data obtained through the seasonal monitoring program (SMP) time domain reflectometry (TDR) are an excellent source for quantifying the moisture-related damage in flexible pavement located in different climates. An artificial neural network (ANN) model was developed based on the SMP data for flexible pavement sections. The results show that higher levels of cracking will lead to an increase in moisture levels within the base layer, which leads to a significant decrease in the base MR. For flexible pavement, the maximum reduction in base MR ranged from 18% to 41% and from 153% to 175% for the pavement sections located in dry and wet regions, respectively. Consequently, the performance of pavement sections located in wet climates is adversely affected. The findings imply that an adequate and timely preservation treatment for cracking sealing (e.g., surface seals) can enhance the pavement’s service life, especially in wet climates. The results suggest that cracks should be sealed when the extent of fatigue cracking is within 6% and 11% for the flexible pavement sections located in wet and dry climates, respectively.

Rational Selection of Factors of Safety in Reliability-Based Design of Flexible Pavements in Saudi Arabia

1996 ◽  
Vol 1540 (1) ◽  
pp. 39-47 ◽  
Author(s):  
A. Samy Noureldin ◽  
Essam Sharaf ◽  
Abdulrahim Arafah ◽  
Faisal Al-Sugair
Keyword(s):  
Saudi Arabia ◽  
Performance Prediction ◽  
Flexible Pavement ◽  
Pavement Design ◽  
Pavement Performance ◽  
Design Performance ◽  
Reliability Based Design ◽  
Pavement Engineering ◽  
Pavement Performance Prediction ◽  
Selection Of

Explicit applications of reliability in pavement engineering have been of interest to pavement engineers for the last 10 years. Variabilities in parameters affecting pavement design performance result in variability in pavement performance prediction and thus affect the reliability of how long the pavement will last. Rational quantification of those variabilities is essential for incorporating reliability and selecting the proper factors of safety in the pavement design performance process. The prevailing methodology in Saudi Arabia of quantifying the variability in pavement performance due to the variabilities of the parameters affecting that performance is demonstrated. Factors of safety for flexible pavement design at various reliability levels and based on those prevailing variabilities are presented. These factors of safety are recommended for flexible pavement design in Saudi Arabia.

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