A Proposed New Method for Roughness Quantification of Concrete Joints and Cracks

The characteristics of concrete joint roughness and crack width are of paramount importance when studying the shear behavior of joints and cracks. These characteristics play a fundamental role in determining the contribution of each of the three shear mechanism; namely friction, shearing through and the dilation components in the overall shear strength at the crack or joint interface. However, in almost all prior studies of shear transfer across joints and cracks, no attempt was made to accurately quantify the roughness of concrete joint or crack surface. In the past, substantial levels of empiricism were used to model and predict shear behavior along discontinuities. This empiricism can be attributed mainly to the lack of an accurate measure for quantifying roughness. A new method that captures all critical characteristics of joint roughness is proposed. The new method is based on the logical assumption that an accurate description of roughness should reflect the following three important aspects of roughness: the irregularity of the surface, the amplitude of different roughness features, and the frequency of occurrence of roughness features with different amplitudes. Based on laboratory testing, the proposed method was found to capture all three aspects of a rough surface successfully. It is proposed that the surface roughness should be described using the form RI(D, kl, hl), where RI will be called the Roughness Index, D is the fractal dimension, kl is the Korcak Number, and hl is the Hurst Number with the subscript l indicating the stride length. These parameters are described in detail in this paper.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 90-99
  • Monograph Title: Pavements and Materials: Modeling, Testing, and Performance

Subject/Index Terms

Filing Info

  • Accession Number: 01142137
  • Record Type: Publication
  • ISBN: 9780784410080
  • Files: TRIS
  • Created Date: Oct 6 2009 12:55PM