RESULTS FOR BOND IN CONCRETE

Definition: (1) adhesion of concrete or mortar to reinforcement or other surfaces against which it is placed, including friction and mechanical interlock; (2) adhesion of cement paste to aggregate; (3) adhesion, cohesion, or both between materials; (4) patterns formed by the exposed faces of masonry units, for example, running bond or Flemish bond.- ACI Concrete Terminology


Bond is critical to the interaction of reinforcing material (whether steel, reinforced polymer, or other material) and concrete; exceeding bond stress between the reinforcing bar and the concrete results in some form of cracking, delamination, or pull-out of the bar.

Bond can also refer to adhesive force between cement paste and aggregate, creating a resistance to tensile or shear stresses in the concrete itself.

In instances where concrete is placed against a hardened concrete, the two can become bonded to each other. Often a cement paste is applied to wet the hardened material, improving the chemical interaction at the surface. Bonding agents are also available to assure bond between distinct concrete surfaces.