Download or read book Pavement Deflection Data as a Tool for the Prediction of Freeze thaw Response written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Winter pavement overload permits and spring load restrictions areimportant to maximize pavement life. In cold regions freeze and thaw conditions have a great effect on the bearing capacity of asphalt concrete (AC) pavement and its sublayers. Studying AC surface deflections from falling weight deflectometer (FWD) tests assists in determining the condition of the surface, base, and subgrade layers of a pavement system. FWD test results are taken from the LTPP Information Management System (IMS). FWD data deflectionbasin indices can be calculated to analyze AC pavement at different seasonalconditions. This data will aid in determining times when load permits and restrictions should be applied. Seasonal effects on AC pavements significantly affect the strength of theAC sublayers. In freezing temperatures the AC pavement and its sublayers become much stronger, where overload permits can be granted. However, when the system thaws the layers become extremely weak. Pavement is subject to damage and FWD tests show significant increases in surface deflection. When this happens spring load restrictions should be utilized to preserve the pavement. An in depth study of FWD data can be used to recommend the best times to enforce winter overload permits and spring load restrictions. Using the BISAR computer program, AC pavement can be modeled to represent FWD behavior at various times.

Download or read book Predicting the Effects of Freezing and Thawing on Pavement Support written by Craig H. Benson and published by . This book was released on 1998 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to develop a method to predict the timing of weight limits on secondary highways in Wisconsin. Two types of weight limits are of interest: overloads when the pavement is frozen and weight restrictions during thawing and post-thawing recovery period. To meet this objective, three sections of secondary highways with flexible pavements were instrumented and monitored to determine how freezing, thawing, and post-thaw recovery affect pavement stiffness. Data collected from these sites were used to develop a computer model (UWFrost) that can be used to predict seasonal changes in the support capacity of pavements.

Download or read book Field and Numerical Investigation to Determine the Impact of Environmental and Wheel Loads on Flexible Pavement written by Alireza Bayat and published by . This book was released on 2009 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a growing interest for the use of mechanistic procedures and analytical methods in the design and evaluation of pavement structure rather than empirical design procedures. The mechanistic procedures rely on predicting pavement response under traffic and environmental loading (i.e., stress, strain, and deflection) and relating these responses to pavement field performance. A research program has been developed at the Center for Pavement and Transportation Technology (CPATT) test track to investigate the impact of traffic and environmental parameters on flexible pavement response. This unique facility, located in a climate with seasonal freeze/thaw events, is equipped with an internet accessible data acquisition system capable of reading and recording sensors using a high sampling rate. A series of controlled loading tests were performed to investigate pavement dynamic response due to various loading configurations. Environmental factors and pavement performance were monitored over a two-year period. Analyses were performed using the two dimensional program MichPave to predict pavement responses. The dynamic modulus test was chosen to determine viscoelastic properties of Hot Mix Asphalt (HMA) material. A three-step procedure was implemented to simplify the incorporation of laboratory determined viscoelastic properties of HMA into the finite element (FE) model. The FE model predictions were compared with field measured pavement response. Field test results showed that pavement fully recovers after each wheel pass. Wheel wander and asphalt mid-depth temperature changes were found to have significant impact on asphalt longitudinal strain. Wheel wander of 16 cm reduced asphalt longitudinal strains by 36 percent and daily temperature fluctuations can double the asphalt longitudinal strain. Results from laboratory dynamic modulus tests found that Hot Laid 3 (HL3) dynamic modulus is an exponential function of the test temperature when loading frequency is constant, and that the HL3 dynamic modulus is a non-linear function of the loading frequency when the test temperature is constant. Results from field controlled wheel load tests found that HL3 asphalt longitudinal strain is an exponential function of asphalt mid-depth temperature when the truck speed and wheel loading are constant. This indicated that the laboratory measured dynamic modulus is inversely proportional to the field measured asphalt longitudinal strain. Results from MichPave finite element program demonstrated that a good agreement between field measured asphalt longitudinal strain and MichPave prediction exists when field represented dynamic modulus is used as HMA properties. Results from environmental monitoring found that soil moisture content and subgrade resilient modulus changes in the pavement structure have a strong correlation and can be divided into three distinct Seasonal Zones. Temperature data showed that the pavement structure went through several freeze-thaw cycles during the winter months. Daily asphalt longitudinal strain fluctuations were found to be correlated with daily temperature changes and asphalt longitudinal strain fluctuations as high as 650 [mu]m/m were recorded. The accumulation of irrecoverable asphalt longitudinal strain was observed during spring and summer months and irrecoverable asphalt longitudinal strain as high as 2338 [mu]m/m was recorded.

Download or read book A Statistical Evaluation of Soil and Climatic Parameters Affecting the Change in Pavement Deflection During Thawing of Subgrades written by Edwin J. Chamberlain and published by . This book was released on 1981 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report analyzes the results of a field study previously reported by Scrivner et al. (1969) for the National Cooperative Highway Research Program. These authors studied the seasonal pavement deflection characteristics of 24 test sites on roads in service in regions with freezing indexes ranging from 100 F-days to 2100 F-days. They used the Dynaflect cyclic pavement loading device to determine the pavement system response. Of specific interest to my analysis was the increased pavement deflection after freezing and thawing and the time to recovery of normal deflection characteristics. These characteristics were related to soil and climatic factors using statistical techniques. The most significant observations of this statistical analysis are: (1) that the freezing index is not a significant parameter in determining the percent increase in pavement deflection during thawing, and (2) that the recovery time is inversely proportional to the depth of freezing. As was expected, the most significant variable affecting the increase in pavement deflection was the frost susceptibility classification. This observation reinforces the necessity for careful selection of soil materials used in pavement systems. (Author).

Download or read book Prediction of Deflection Response of Flexible Pavements Under Dynamic Loads written by Jim W. Hall and published by . This book was released on 1995 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transportation Research Record written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Statistical Evaluation of Soil and Climatic Parameters Affecting the Change in Pavement Deflection During Thawing of Subgrades written by Edwin J. Chamberlain and published by . This book was released on 1981 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Special Report written by and published by . This book was released on 1989 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 7th RILEM International Conference on Cracking in Pavements written by A. Scarpas and published by Springer Science & Business Media. This book was released on 2012-08-30 with total page 1340 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recent past, new materials, laboratory and in-situ testing methods and construction techniques have been introduced. In addition, modern computational techniques such as the finite element method enable the utilization of sophisticated constitutive models for realistic model-based predictions of the response of pavements. The 7th RILEM International Conference on Cracking of Pavements provided an international forum for the exchange of ideas, information and knowledge amongst experts involved in computational analysis, material production, experimental characterization, design and construction of pavements. All submitted contributions were subjected to an exhaustive refereed peer review procedure by the Scientific Committee, the Editors and a large group of international experts in the topic. On the basis of their recommendations, 129 contributions which best suited the goals and the objectives of the Conference were chosen for presentation and inclusion in the Proceedings. The strong message that emanates from the accepted contributions is that, by accounting for the idiosyncrasies of the response of pavement engineering materials, modern sophisticated constitutive models in combination with new experimental material characterization and construction techniques provide a powerful arsenal for understanding and designing against the mechanisms and the processes causing cracking and pavement response deterioration. As such they enable the adoption of truly "mechanistic" design methodologies. The papers represent the following topics: Laboratory evaluation of asphalt concrete cracking potential; Pavement cracking detection; Field investigation of pavement cracking; Pavement cracking modeling response, crack analysis and damage prediction; Performance of concrete pavements and white toppings; Fatigue cracking and damage characterization of asphalt concrete; Evaluation of the effectiveness of asphalt concrete modification; Crack growth parameters and mechanisms; Evaluation, quantification and modeling of asphalt healing properties; Reinforcement and interlayer systems for crack mitigation; Thermal and low temperature cracking of pavements; and Cracking propensity of WMA and recycled asphalts.

Download or read book Improved Prediction Models for PCC Pavement Performance related Specifications Final report written by and published by . This book was released on 2000 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The current performance-related specifications (PRS) methodology has been under development by the Federal Highway Administration (FHWA) for several years and has now reached a level at which it can be implemented by State highway agencies. PRS for highway pavements depend heavily on performance prediction models to determine the impact of varying levels of construction quality. This study focused on the improvement of the key distress and smoothness prediction models used in the PRS for jointed plain concrete pavement (JPCP). Performance models for transverse joint faulting, transverse slab cracking, transverse joint spalling, and smoothness (International Roughness Index [MI]) were evaluated and then improved substantially. This was accomplished using a comprehensive national database of JPCP performance data, along with sound statistical and engineering techniques. Performance model calibration guidelines were also developed so that a State cari calibrate any of these models specifically to its pavement performance data. The PaveSpec PRS demonstration software was upgraded to Version 3.0 under this study. Some of the specific improvements incorporated in PaveSpec 3.0 include: 1) incorporation ofyim proved distress indicator models, as well as the ability to calibrate or modify the default models, 2) sensitivity analysis capabilities, 3) expected pay charts, and 4) online help. Appendix A of this report contains a complete updated PaveSpec User's Guide"--Technical report documentation page

Download or read book Applications of Emerging Technologies in Transportation written by and published by . This book was released on 1998 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1980 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Canadian Journal of Civil Engineering written by and published by . This book was released on 2000 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Pavement Prediction Models written by Ying-Haur Lee and published by . This book was released on 1994 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Highway Research Abstracts written by and published by . This book was released on 1991 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1980 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book System Issues of Concern to Waterway Operators written by National Research Council (U.S.). Transportation Research Board and published by . This book was released on 1986 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: