2013 Session: 474

• Characterization of Crack Data from Continuously Reinforced Concrete Pavements on Lean Concrete Base
  Abstract: Extensive crack width and crack spacing data from recently constructed continuously reinforced concrete pavements (CRCP) on lean concrete base in China were collected and statistically analyzed in this study. A total of 29 CRCP sections were observed which lead to 1171 crack data. The cracks were classified into six different types according to their shapes and patterns. Kolmogorov-Smirnov test shows that CRCP crack spacing follows a four-parameter Dagum distribution. ANOVA tests show that slab thickness does not have a significant impact on crack spacing. However, it has a significant impact on crack width. Measured data show the crack spacing is not correlated to crack width. In addition, validation result shows that Mechanistic-Empirical Pavement Design Guide (MEPDG) crack spacing model significantly underestimates the field mean crack spacing.
  Authors: Zhang, Xiao; Zhao, Duijia
  Authors: Zhang, Xiao; Zhao, Duijia
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-2517
• Three-Dimensional Finite Element Model for Analysis of Transverse Cracking in Continuously Reinforced Concrete Pavement
  Abstract: In this study, a three dimensional finite element model was developed to investigate crack development and mechanical responses of steel bar and concrete slab of continuously reinforced concrete pavement. An incremental method was adopted to take into account variations of free contraction strains and material properties of concrete in the early stage after casting. A model of mechanical interaction between steel and concrete was developed and values of the parameters were identified by comparing calculated and measured responses. Effects of crack spacing, base course stiffness and depth of steel bar on steel bar and concrete slab stresses and crack width were examined. It was found that strong bonding between steel and concrete leads to higher stresses in steel bar and concrete slab. Short crack spacing reduces tensile stresses in steel bar and concrete slab and crack width. Small peak in tensile stress on the top of slab near crack appears when stiffness of base course is low. The peak of tensile stress might cause “secondary” crack near “primary” crack. Deeper steel bar position leads to wider crack width at the top of slab. Embedding steel bars at a third depth of slab thickness is a reasonable practice to keep crack width tight on the slab surface and prevent water penetration.
  Authors: Nishizawa, Tatsuo
  Authors: Nishizawa, Tatsuo
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-3684
• Characterization of Cracking Behavior of Continuously Reinforced Concrete Pavements Under Current Design Concept in Belgium
  Abstract: In Belgium, Continuously Reinforced Concrete Pavements (CRCP) are being used on large scale for more than forty years. Under the initial standard design concept an apparently very unfavourable cracking pattern develops with a high probability of clusters of closely spaced cracks. The standard design underwent several main changes over time with regard to longitudinal reinforcement rate, depth of the reinforcement layer, presence of an asphalt interlayer, pavement thickness, concrete mix, surface finishing and lane width. The current concept that has been used since 1995 is quite satisfactory since no major distresses have occurred since then. The primary objective of this paper is to investigate the crack spacing and crack width characteristics of the CRCPs under the current design concept. More specifically the focus is on the influence of the different reinforcement percentages on the early age cracking behaviour of CRCP. Several different approaches were used to analyse the crack spacing, especially, the probability of clusters of closely spaced cracks. Crack width data including the movement of the slab were also obtained by linear variable differential transformer (LVDT) measurements.
  Authors: Ren, Dongya; Houben, Lambert; Rens, Luc
  Authors: Ren, Dongya; Houben, Lambert; Rens, Luc
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-1302
  Practice-Ready: Yes
• Characterization of Cracking Behavior of Continuously Reinforced Concrete Pavements Under Current Design Concept in Belgium
  Authors: Ren, Dongya
  Authors: Ren, Dongya
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-1302
• Three-Dimensional Finite Element Model for Analysis of Transverse Cracking in Continuously Reinforced Concrete Pavement
  Authors: Nishizawa, Tatsuo
  Authors: Nishizawa, Tatsuo
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-3684
• Enhancements to Punchout Prediction Model in MEPDG Design Procedure
  Authors: Darter, Michael
  Authors: Darter, Michael
  Year: 2013
  Document Type: Presentation
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-5249
• Enhancements to Punchout Prediction Model in MEPDG Design Procedure
  Abstract:

  This paper presents the continuously reinforced concrete pavement (CRCP) punchout prediction model in the Mechanistic-Empirical Pavement Design Guide (formerly MEPDG, currently DARWin-ME) and the various improvements to the procedure since the original MEPDG software program was released in 2004 as a product of the National Cooperative Highway Research Program (NCHRP) project 1-37A. The punchout prediction procedure is based on mechanistic principles to estimate top-down fatigue damage in the CRCP and an empirical punchout prediction model calibrated to field data. The mechanistic structural evaluation includes models to estimate crack width, crack spacing, load transfer efficiency (LTE) across the transverse cracks, and fatigue damage accumulation based on Miner’s hypothesis. The punchout prediction model was calibrated to field distress development data obtained from CRCP sections nationwide. A majority of the field sections were part of the Long Term Pavement Performance (LTPP) experiment, and therefore a majority of the materials, traffic, climate, and construction data were obtained from the LTPP database.Since 2004, NCHRP has undertaken two main technical enhancements to DARWin-ME. The first was the revision made under project 1-40D to address comments received from an independent panel that performed a formal review under project 1-40A. Further, due to the discovery of a systematic error in the portland cement concrete (PCC) coefficient of thermal expansion (CTE) test procedure, appropriate CTE corrections were made in the LTPP database. Under project 20-07/task 288, the punchout model was recalibrated to account for this error. The models developed show that the procedure makes reasonable crack spacing, crack width, and punchout predictions that match field observations. Further, the models result in averagely similar CRCP thickness designs before and after the CTE corrections were made as long as corresponding model calibration coefficients are used.

  Authors: Rao, Chetana; Darter, Michael I.
  Authors: Rao, Chetana; Darter, Michael I.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-5249
  Practice-Ready: Yes