Evaluation of Long-Term Pavement Performance Data Using HDM-III Probabilistic Failure-Time Models for Crack Initiation in Bituminous Pavements

1997 ◽  
Vol 1592 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Thomas J. Van Dam ◽  
Andrew D. Chesher ◽  
David G. Peshkin
Keyword(s):  
Crack Initiation ◽  
Failure Time ◽  
Climatic Factors ◽  
Pavement Performance ◽  
General Applicability ◽  
Highway Design ◽  
Depth Analysis ◽  
Pavement Deterioration ◽  
Bituminous Pavements

Cracking is perhaps the most important distress in bituminous pavements. It plays a key role in modeling bituminous pavement performance in the World Bank’s Highway Design and Maintenance Standards Model Version III (HDM-III) with the belief that a cracked pavement is susceptible to moisture ingress, which accelerates pavement deterioration. Strategic Highway Research Program Long-Term Pavement Performance (LTPP) data were analyzed by using the probabilistic failure-time crack initiation models previously developed for use in HDM-III. On the basis of that analysis, it is concluded that the HDM-III models do not accurately capture the climatic factors that play a role in linear cracking initiation typically observed in North America. When considering only fatigue-related cracking, HDM-III models could be successfully fit to the data, but concerns related to the shape parameter call into question their general applicability. It is concluded that although some aspects of this analysis suggest that HDM-III models adequately model fatigue-related crack initiation in LTPP pavement sections, overall the results are inconclusive and a more in-depth analysis needs to be conducted.

Evaluation of subgrade and climatic zone influences on pavement performance in the Canadian Strategic Highway Program's (C-SHRP) Long-Term Pavement Performance (LTPP) study

2002 ◽  
Vol 39 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Susan Tighe
Keyword(s):  
Climatic Factors ◽  
Pavement Performance ◽  
Valuable Insight ◽  
Pavement Rehabilitation ◽  
Traffic Loading ◽  
Subgrade Soils ◽  
Pavement Roughness ◽  
Subgrade Soil ◽  
Asphalt Overlays

Sixty-five sections in 24 provincial test sites received pavement rehabilitation comprising of various thicknesses of asphalt overlays, as part of the Canadian Long-Term Pavement Performance (C-LTPP) study, which was initiated in 1989. This paper describes the impacts of the various alternative rehabilitation treatments on pavement performance in terms of roughness progression under comparative climatic, subgrade soil, and traffic loading conditions. Some findings from this study include (i) in wet, high-freeze zones, thinner overlays show a higher rate of roughness progression than thicker overlays, regardless of subgrade type; (ii) in dry, high-freeze zones, roughness progression for medium and thick overlays is relatively small; (iii) in wet, low-freeze zones, thinner overlays combined with fine subgrade soils show the highest rate of roughness progression; and (iv) traffic, in terms of equivalent single axle loads (ESALs), seemed to have a limited effect on all of the above; this was attributed largely to the fact that all of the traffic essentially fell into one level, where 200 000 ESALs per year was designated as the boundary between low and high traffic levels. The methodology developed in this paper provides valuable insight into how subgrade and climatic factors influence pavement performance and can be applied to performance trend analysis of other pavements with similar climatic, subgrade, and traffic loading conditions.Key words: subgrade type, climatic zones, pavement roughness, international roughness index (IRI), Long-Term Pavement Performance (LTPP).

Development of Canadian asphalt pavement deterioration models to benchmark performance

2003 ◽  
Vol 30 (4) ◽  
pp. 637-643 ◽  
Author(s):  
Chris Raymond ◽  
Susan Tighe ◽  
Ralph Haas ◽  
Leo Rothenburg
Keyword(s):  
Univariate Analysis ◽  
Pavement Performance ◽  
Site Location ◽  
Site Factors ◽  
Asphalt Overlay ◽  
Pavement Roughness ◽  
Pavement Deterioration ◽  
Individual Project ◽  
Asphalt Overlays

The Canadian Long Term Pavement Performance (C-LTPP) study, initiated in 1989, involves 65 sections located at 24 sites constructed with various asphalt overlay rehabilitation treatments. This study investigates the impacts of the various alternative rehabilitation treatments on pavement roughness progression. A series of models are developed for predicting the rate of pavement deterioration occurring for the first 8 years of service. The models examine both within-site factors and between-site factors. Site location is found to be the primary influence on the rate of pavement deterioration. Overlay thickness and the amount of cracking prior to rehabilitation are also determined to influence pavement deterioration at a strong statistical level. Models are provided for benchmarking the performance of pavements across Canada, for comparison with individual project designs, and for estimating the performance of designs with different overlay thickness.Key words: Canadian Long Term Pavement Performance program, roughness, pavement deterioration, site effects, asphalt overlays, benchmark, univariate analysis.

Deterioration of Asphalt Pavement at Long-Term Pavement Performance Program Site 49-1001 in Utah

2005 ◽  
Vol 1933 (1) ◽  
pp. 121-125
Author(s):  
Brandon J. Blankenagel ◽  
W. Spencer Guthrie
Keyword(s):  
Base Layer ◽  
Pavement Performance ◽  
Falling Weight Deflectometer ◽  
Water Drainage ◽  
Base Materials ◽  
Pavement Deterioration ◽  
Pavement Base ◽  
Aggregate Base ◽  
Falling Weight

Highway 191 near Bluff, Utah, features a well-monitored section of the long-term pavement performance (LTPP) program. Constructed in 1980, this section of flexible pavement performed well for nearly 13 years. Through this time, cracking of the asphalt layer was minimal. In the fourteenth year, however, the extent of longitudinal cracking in the wheel path increased and necessitated placement of a chip seal on the pavement surface. The purpose of this research was to determine the cause of pavement deterioration using LTPP data. Deflection basins obtained from falling-weight deflectometer testing were analyzed to investigate the extent to which structural degradation influenced deterioration of the pavement. Pavement layer modulus values were plotted against time and clearly show that weakening of the pavement base layer immediately preceded the occurrence of cracking. The geography of the site, as documented in photographs, supports the conclusion that inadequate water drainage at the site permitted saturation of the aggregate base layer during a period of midsummer flooding. This finding emphasizes the importance of specifying non-moisture-susceptible base materials and providing necessary drainage works in pavement design.

Effect of long climatic ageing on the microstructure of the surface of сarbon-fiber-reinforced plastics on base epoxy matrix

2019 ◽  
pp. 157-169 ◽  
Author(s):  
I. S. Deev ◽  
E. V. Kurshev ◽  
S. L. Lonsky
Keyword(s):  
Climatic Factors ◽  
Temperate Climate ◽  
Fiber Reinforced ◽  
Humid Climate ◽  
Climatic Zones ◽  
Reinforced Plastics ◽  
Carbon Plastics ◽  
Fiber Reinforced Plastics ◽  
Determining Factor

Studies and experimental data on the microstructure of the surface of samples of epoxy сarbon-fiber-reinforced plastics that have undergone long-term (up to 5 years) climatic aging in different climatic zones of Russia have been conducted: under conditions of the industrial zone of temperate climate (Moscow, MTsKI); temperate warm climate (Gelendzhik, GTsKI); a warm humid climate (Sochi, GNIP RAS). It is established that the determining factor for aging of carbon plastics is the duration of the complex effect of climatic factors: the longer the period of climatic aging, the more significant changes occur in the microstructure of the surface of the materials. The intensity of the aging process and the degree of microstructural changes in the surface of carbon plastics are affected by the features of the climatic zone. general regularities and features of the destruction of the surface of carbon plastics after a long-term exposure to climatic factors have been established on the basis of the analysis and systematization of the results of microstructural studies.

scholarly journals Design of a Database of Case Studies and Technologies to Increase the Diffusion of Low-Temperature Waste Heat Recovery in the Industrial Sector

2021 ◽  
Vol 13 (9) ◽  
pp. 5223
Author(s):  
Miriam Benedetti ◽  
Daniele Dadi ◽  
Lorena Giordano ◽  
Vito Introna ◽  
Pasquale Eduardo Lapenna ◽  
...  
Keyword(s):  
Low Temperature ◽  
Case Studies ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Industrial Sector ◽  
Implementation Rate ◽  
Depth Analysis ◽  
Technology Market

The recovery of waste heat is a fundamental means of achieving the ambitious medium- and long-term targets set by European and international directives. Despite the large availability of waste heat, especially at low temperatures (<250 °C), the implementation rate of heat recovery interventions is still low, mainly due to non-technical barriers. To overcome this limitation, this work aims to develop two distinct databases containing waste heat recovery case studies and technologies as a novel tool to enhance knowledge transfer in the industrial sector. Through an in-depth analysis of the scientific literature, the two databases’ structures were developed, defining fields and information to collect, and then a preliminary population was performed. Both databases were validated by interacting with companies which operate in the heat recovery technology market and which are possible users of the tools. Those proposed are the first example in the literature of databases completely focused on low-temperature waste heat recovery in the industrial sector and able to provide detailed information on heat exchange and the technologies used. The tools proposed are two key elements in supporting companies in all the phases of a heat recovery intervention: from identifying waste heat to choosing the best technology to be adopted.

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.

Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations and Fisheries of the Red Lakes, Minnesota, 1930–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.
Keyword(s):  
Growth Rate ◽  
Yellow Perch ◽  
Climatic Factors ◽  
Perca Flavescens ◽  
Growing Season ◽  
Commercial Fishery ◽  
Class Strength ◽  
Parent Stock ◽  
Catch Statistics

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield

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