Title: Shear Bond Strength Between Coarse Aggregate and Cement Paste or Mortar
Author(s): Michael A. Taylor and Bengt B. Broms
Publication: Journal Proceedings
Appears on pages(s): 939-958
Microscopic cracks which develop during settling and hardening, and during subsequent loading form either in the cement or mortar matrix, or along the aggregate-matrix interfaces. The latter cracks may be caused either by tensile or by shear stresses (tensile or shear bond cracks, respectively), or by combinations of tensile and shear stresses. The shear bond strength at the interface, as affected by type of aggregate and composition of cement or mortar matrix (at different water-cement ond cement-sand ratios), has been investigated. The shear bond strength is evaluated in terms of the friction angle 4 and the cohesion c. The shear bond strength was found to be governed chiefly by the internal friction and 4 which appears to be nearly independent of the composition of both aggregate and matrix. A hypothesis for predicting location and development of shear bond cracks is presented. Its validity has been investigated by microcrack studies on longitudinal slices cut from plain concrete cylinders which have been loaded in axial compression.