Effective initial crack depth in exposed concrete surfaces

Matthew A. Beyer, Jeffery Raphael Roesler

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Microcracking at the surface of concrete slabs can result in a reduction in slab strength at the surface and a decrease in the flexural load carrying capacity of the slab especially when undergoing loading that produces top tensile stresses. The majority of this surface cracking is the result of drying shrinkage gradients and slab restraint. The use of an effective initial crack depth (ae) has been previously proposed as a method to model this reduction in slab strength due to surface microcracking. The two-parameter fracture model procedure was modified to make calculations of the effective initial crack depth in three-point bending specimens to examine if reasonable values of ae can be measured in a laboratory setting using fracture mechanics principles. Testing of concrete beams exposed to two curing environments (moist- and dry-cured) indicates that the effective initial crack depth, approximately 50 mm in this study, can be calculated using a dependent relationship between crack depth and compliance values. The procedure was verified by calculating additional fracture parameters of the concrete, which were found to be comparable to values presented in the literature for similar concrete materials and mixtures. The ability to quantify an effective notch depth at the surface of the slab can enable future modeling to determine the effective strength difference of concrete slabs under bottom or top tensile loading conditions.

Original languageEnglish (US)
Title of host publication9th International Conference on Concrete Pavements
Subtitle of host publicationThe Golden Gate to Tomorrow's Concrete Pavements
Pages755-767
Number of pages13
StatePublished - Dec 1 2008
Event9th International Conference on Concrete Pavements: The Golden Gate to Tomorrow's Concrete Pavements - San Francisco, CA, United States
Duration: Aug 17 2008Aug 21 2008

Publication series

Name9th International Conference on Concrete Pavements: The Golden Gate to Tomorrow's Concrete Pavements
Volume2

Other

Other9th International Conference on Concrete Pavements: The Golden Gate to Tomorrow's Concrete Pavements
CountryUnited States
CitySan Francisco, CA
Period8/17/088/21/08

    Fingerprint

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Civil and Structural Engineering
  • Building and Construction
  • Architecture

Cite this

Beyer, M. A., & Roesler, J. R. (2008). Effective initial crack depth in exposed concrete surfaces. In 9th International Conference on Concrete Pavements: The Golden Gate to Tomorrow's Concrete Pavements (pp. 755-767). (9th International Conference on Concrete Pavements: The Golden Gate to Tomorrow's Concrete Pavements; Vol. 2).