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
Total Pages: 197
Release: 2011-03-16
Genre: Technology & Engineering
ISBN: 9400712391

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.

Delamination of Bonded Concrete Overlays at Early Ages

Delamination of Bonded Concrete Overlays at Early Ages
Author: James Ray Lundy
Publisher:
Total Pages: 100
Release: 1991
Genre: Laminated materials
ISBN:

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.

Evaluation of Bonding Between Ultra-thin Portland Cement Concrete Overlays and Asphalt Cement Concrete

Evaluation of Bonding Between Ultra-thin Portland Cement Concrete Overlays and Asphalt Cement Concrete
Author: John Michael Hart
Publisher:
Total Pages: 404
Release: 2000
Genre:
ISBN:

Laboratory testing and full-scale field testing were used to accomplish the research objective. Laboratory testing involved monitoring interface strains in fabricated PCC/ACC composite beams subjected to either static or dynamic flexural loading. Variables investigated included ACC surface preparation, PCC thickness, and synthetic fiber reinforcement usage. Field testing involved monitoring interface strains and temperatures, falling weight deflectometer deflection responses, direct shear strengths, and distresses on a 7.2 mile Iowa Department of Transportation UTW project (HR-559). Variables investigated included ACC surface preparation, PCC thickness, synthetic fiber reinforcement usage, and joint spacing. The results of both laboratory and field testing are presented and summarized in this paper.