Download or read book On Thaw Weakening of Pavement Structures written by Erik Simonsen and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This doctoral thesis focuses on thaw weakening of pavement structures. The thesis consists of a literature review (Paper I), modeling and field verification of an evaluation procedure for pavements exposed to seasonal frost conditions (Papers II and III), and experimental studies on the resilient properties of unbound road materials during freezing and thawing (Papers IV and V).The literature review describes factors identified as significant for the extent of weakening during soil thawing, e.g. soil type, permeability, drainage conditions and rate of thaw. Also the rate of freezing may indirectly affect thaw weakening. Persisting structural changes in soil fabric are also frequently observed. Findings concerned with frost action effects on a number of test roads are presented. The effects of frost action on resilient behavior are also described. In conclusion, attempts to develop semi-mechanistic pavement design and evaluation procedures for pavements in cold regions are presented. Although the effects of climate on pavement structures are recognized as a major contributor to the deterioration of pavement structures in cold regions, only a few models concerned with both frost heave and thaw settlement have been developed. In Paper II, a coupled mass and heat transfer model is tested and evaluated with respect to parameters critical to thaw weakening. The results indicate that soil temperature is predicted very well and soil moisture relatively well during freezing and thawing. Paper III presents an initial attempt to implement a commercially available finite element program in an evaluation procedure for pavements in seasonal frost areas. The results are compared with data from an extensively instrumented test road and indicate that surface deflection and relative change in pavement stiffness are predicted very accurately. Although a time lag between maximum measured and predicted surface deflection is observed during thawing, the procedure is found to be promising. The results from extensive resilient modulus laboratory tests during freezing and thawing are presented in Paper IV. The results indicate that all the soils exhibited substantially decreased resilient modulus after freeze-thaw. The decrease is ascribed to an observed increase in volume, and consequently a looser soil structure, due to freeze-thaw. A significant hysteresis for the clay soil in warming and cooling was also observed. Variable confining pressure (VCP) triaxial tests are generally preferred to constant confining pressure (CCP) tests, due to the more realistic stress application. However, VCP tests have never been utilized for investigation of freeze-thaw effects on unbound road materials. Paper V reports results obtained utilizing CCP and VCP triaxial tests for the characterization of resilient soil behavior during freezing and thawing. The results indicate a significant difference in moduli computed from CCP and VCP data. However, resilient moduli display compatible values if interpreted in terms of mean values of deviator stress and mean normal stress. With regard to freeze-thaw effects on resilient moduli, the results are inconsistent with previous findings. However, this can be explained by the different test conditions applied. (Abstract shortened by UMI.)
Download or read book PCC Airfield Pavement Response During Thaw Weakening Periods A Field Study written by and published by DIANE Publishing. This book was released on with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Determining the Critical Thaw weakened Period in Asphalt Pavement Structures written by J. McBane and published by . This book was released on with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of the Critical Thaw weakened Period in Asphalt Pavement Structures written by Jim McBane and published by . This book was released on 1985 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement and Analysis of Pore Water Pressure in Thawing Pavement Structures Subjected to Dynamic Loading written by Jean Michel Hovan and published by . This book was released on 1997 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Montana Highway Pavements During Spring Thaw written by Vincent C. Janoo and published by . This book was released on 2002 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highway pavements in seasonal frost areas undergo annual freeze thaw cycles. Pavements constructed for the design load capacity can become weak during spring thaw. In 1995, the Montana Department of Transportation (MDT) initiated a study on developing road restrictions during the spring thaw. Selected sites throughout Montana were instrumented. Field measurements of deflection, moisture, and temperature were made during the winter/spring of 1996 to 1997 and 1997 to1998. The analysis determined thaw weakening characteristics of the sites and developed subgrade modulus values for use in future design of pavement structures in Montana. Based on the moisture data, the base course layers at Dickey Lake, Wolf Point, Scobey/Redstone, and East Glacier are prone to thaw weakening. Deflection data indicate that the bases at Bull Mountain, Swan Lake, and Scobey/Redstone may be prone to thaw weakening. The subgrade at Dickey Lake, East Glacier, Bull Mountain, Swan Lake, and Scobey/Redstone may also be prone to thaw weakening. The length of thaw weakening varied from 4 days (Scobey/Redstone) to 3 weeks (East Glacier). This report provides a general description of the test sites, the measurements and analysis of the data, results of the analysis, and recommendations based on the results. In addition, the report quantifies the effects of thaw weakening on typical roads in Montana based on deflection, surface and subsurface moisture, temperature, and other atmospheric measurements taken by MDT.
Download or read book Special Report written by and published by . This book was released on 1996 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PCC Airfield Pavement Response During Thaw weakening Periods written by Vincent C. Janoo and published by . This book was released on 1996 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AASHTO Guide for Design of Pavement Structures 1993 written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1993 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.
Download or read book Prediction of Climatic Effects and Pavement Response in Frost Sensitive Roads written by and published by . This book was released on 1996 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frost Action in Soils written by American Society of Civil Engineers. Cold Regions Engineering Division and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Prepared by the Frozen Ground Committee and the Transportation and Infrastructure Committee of the Cold Regions Engineering Division of ASCEFrost Action in Soils: Fundamentals and Mitigation in a Changing Climate presents the challenges of cold regions engineering in a changing climate, as well as the current practices and state-of-the-art tools for addressing them. Climate change poses questions regarding associated effects on freeze-thaw action and the potential impacts on pavements and other structures in cold regions. In the last 35 years, significant technological advancements addressing frost action in soils have occurred; and tools for instrumentation, measurement, and computer analysis have improved considerably. Thebook explores frost action in soils from different perspectives, as presented in three parts. The first section presents the fundamentals of frost heave and thaw weakening, the impacts on roads and other structures, and the projected effects of climate change on frost action. The second section presents mitigation of frost heave and thaw weakening within pavement structures. The third section highlights three case studies dealing with frost action and mitigation for buildings, roadways, and airfields. This book is a valuable resource for engineers, scientists, and government agencies involved in cold regions engineering and the mitigation of frost action on pavements and other structures
Download or read book Assessment of Pavement Response During Spring Thaw Using Heavy Vehicle Simulator Testing written by J.-P. Bilodeau and published by . This book was released on 2020 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two indoor laboratory studies were performed at Laval University using a heavy vehicle simulator on two very different pavement structures. The flexible pavement structural response was tested in thawing conditions for different loading conditions. These tests were performed to document how the flexible pavement response changes with thaw depth and to validate the main findings and information available in the literature regarding pavement response during spring thaw and spring load restrictions policies. The results collected during the experiment are in accordance with some general findings identified in the literature. More specifically, signs of weakening appear as soon as the thaw front reaches the granular layer beneath the asphalt concrete, at a depth of about 250-300 mm, and peak response values of up to 200 % are observed either while the structure thaws or once thawing is almost completed in the subgrade soil.
Download or read book The Evaluation of Frost Related Effects on Pavements written by Jo A. Lary and published by . This book was released on 1985 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: This summary report describes the field data and analysis techniques used to evaluate the effect of winter ground freezing on WSDOT pavement structures during two thaw periods. Six field test sites were selected in District 2 for deflection testing and in situ instrumentation as well as materials sampling. The results show that a principal mechanism which necessitates load restrictions for some of the WSDOT pavement structures is the weakened condition of the base course during thawing periods. Presented in the report is a single revised load restriction table and criteria to use in determining the time and location for establishing load restrictions.
Download or read book Pavements Unbound written by Andrew Dawson and published by CRC Press. This book was released on 2014-09-01 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly all highway, airport, dock and industrial pavements contain large quantities of untreated aggregate in the form of unbound pavement layers. In many pavements, which are lightly or moderately trafficked, crushed rock or gravel derived aggregates comprise the majority of the construction or, in the case of unsealed pavements, all of the structure. This book provides studies of the performance and description of this material that will help the reader to better understand its characteristics and behaviour both alone and as part of the pavement structure it forms. This work will be useful to practitioners, policy makers, researchers and students. It forms a sequel to the earlier book "Unbound Aggregates in Road Construction" also published by Balkema
Download or read book The Effects of Winter Haul on Low Volume Forest Development Roads written by Palmer Utterback and published by . This book was released on 1995 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Significant Findings from Full scale Accelerated Pavement Testing written by Frederick Hugo and published by Transportation Research Board. This book was released on 2004 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 325: Significant Findings from Full-Scale Accelerated Pavement Testing documents and summarizes the findings from the various experimental activities associated with full-scale accelerated pavement testing programs.
