Method for Quantification of Wear of Sheared Joint Walls Based on Surface Morphology: Fid-Bau Portal

Method for Quantification of Wear of Sheared Joint Walls Based on Surface Morphology

Belem, T. / Souley, M. / Homand, F.

Abstract Roughness and wear evolution of three different joint wall surfaces were characterized using surface roughness and surface wear parameters. Parameters were defined by considering the two components of morphology: waviness (“primary” roughness) and surface roughness (“secondary” roughness). Two surface roughness parameters are proposed: joint interface (or single wall) specific surface roughness coefficient $ SR_{s} $ (0 ≤ $ SR_{s} $ ≤ 1) for quantifying the amount of “pure” roughness (or specific roughness), and degree of joint interface (or single wall) relative surface roughness $ DR_{r} $ (0 ≤ $ DR_{r} $ ≤ 0.5). Two further parameters are also proposed in order to quantify the wear of wall surface: joint interface (or single wall) surface wear coefficient $ Λ_{interface} $, and the degree of joint interface (or single wall) surface wear Dw(interface). The three test specimens were: man-made granite joints with hammered surfaces, man-made mortar joints with corrugated surfaces, and mortar joints prepared from natural rough and undulated schist joint replicas. Shearing under monotonic and cyclic shearing was performed using a computer-controlled bidirectional and biaxial shear apparatus. Joint surface data were measured using a noncontact laser sensor profilometer prior to and after each shear test. Calculation of specific surface roughness coefficient $ SR_{s} $, and degree of surface wear Dw, indicated that the hammered joint interface with predominant interlocking wears much more (>90%) than the corrugated (27%) and the rough and undulated (23%) joint interfaces having localized interlocking points. The proposed method was also successfully linked to the classical wear theory.