Mapping Voids, Debonding, Delaminations, Moisture, and Other Defects Behind or Within Tunnel Linings
Mapping Voids, Debonding, Delaminations, Moisture, and Other Defects Behind or Within Tunnel Linings

Author: Tom Scullion, Stefan Hurlebaus, Dan Zollinger, Zachary Grasley, Soheil Nazarian, Hoda Azari, Deren Yuan, Parisa Shokouhi, Timo Saarenketo, Fulvio Tonon, Transportation Research Board

Publisher: Transportation Research Board

Published:

Total Pages: 686

ISBN-13: 0309274486

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This report from the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies, identifies techniques that provide useful information for evaluating tunnel linings.

Delamination of Bonded Concrete Overlays at Early Ages
Delamination of Bonded Concrete Overlays at Early Ages

Author: James Ray Lundy

Publisher:

Published: 1991

Total Pages: 100

ISBN-13:

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A procedure is developed by which the likelihood of delamination of bonded concrete overlays on continuously reinforced concrete pavements is reduced. The procedure compares the early age interface stress to the expected interface bond strength for a variety of environmental conditions. When the calculated stress exceeds the expected strength, it is recommended that overlay placement be curtailed until the possibility of debonding is reduced. A finite element method program is used to determine the early age stresses resulting from temperature and shrinkage induced volume changes. Stresses were determined for a variety of environmental and material combinations and overlay thicknesses. Analyses show that a significant reduction in stress results from the use of overlay materials which have a lower modulus and thermal coefficient than those of the existing slab. The stresses for a given combination of materials and environmental conditions are compared to the interface bond strength at early ages. Early age interface shear and tensile strengths are estimated from 7-day strength test results. The estimated strength, together with the variability of the interface strength, are used to calculate the likelihood of delamination for a given type of overlay and time of placement. This likelihood can be reduced through the selection of a different overlay material or time of placement.

Mechanisms of Cracking and Debonding in Asphalt and Composite Pavements
Mechanisms of Cracking and Debonding in Asphalt and Composite Pavements

Author: William G. Buttlar

Publisher: Springer

Published: 2018-05-26

Total Pages: 256

ISBN-13: 3319768492

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Premature cracking in asphalt pavements and overlays continues to shorten pavement lifecycles and creates significant economic and environmental burden. In response, RILEM Technical Committee TC 241-MCD on Mechanisms of Cracking and Debonding in Asphalt and Composite Pavements has conducted a State-of-the-Art Review (STAR), as detailed in this comprehensive book. Cutting-edge research performed by RILEM members and their international partners is presented, along with summaries of open research questions and recommendations for future research. This book is organized according to the theme areas of TC 241-MCD - i.e., fracture in the asphalt bulk material, interface debonding behaviour, and advanced measurement systems. This STAR is expected to serve as a long term reference for researchers and practitioners, as it contributes to a deeper fundamental understanding of the mechanisms behind cracking and debonding in asphalt concrete and composite pavement systems.

Bonded Cement-Based Material Overlays for the Repair, the Lining or the Strengthening of Slabs or Pavements
Bonded Cement-Based Material Overlays for the Repair, the Lining or the Strengthening of Slabs or Pavements

Author: Benoît Bissonnette

Publisher: Springer Science & Business Media

Published: 2011-03-16

Total Pages: 197

ISBN-13: 9400712391

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Among different approaches that can be considered for concrete rehabilitation, bonded overlays are often the most economical alternative. The primary purpose of overlays is to extend the life of the candidate structures, either by restoring the quality and integrity of the surface and/or the re-establishing or improving the load-carrying capacity. Nevertheless, the durability of bonded overlay systems still draws concerns in the technical community because of bond sustainability problems encountered in a number of cases. At this time, there is still no accepted design approach or methodology that can warrant the practitioner a successful outcome of the repair. This State-of-Art report summarizes the findings with respect to all aspects involved in the overlaying process.

Significant Findings from Full-scale Accelerated Pavement Testing
Significant Findings from Full-scale Accelerated Pavement Testing

Author: Frederick Hugo

Publisher: Transportation Research Board

Published: 2004

Total Pages: 213

ISBN-13: 0309069742

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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.