If a bonding agent is not used during concrete repairs, what is a likely consequence?

• A. Faster curing
• B. Increased color uniformity
• C. Reduced permeability
• D. Poor adhesion between old and new concrete, leading to delamination or cracking.

Answer: (D)

Bonding agents create a strong connection between old and new concrete at the repair interface, helping the two pours act as a single, continuous material. Without one, the bond is weak and the layers can slip or pull apart as the concrete dries, cures, or experiences temperature and load changes. This can lead to delamination (layers separating) or cracking at the joint as stresses aren’t effectively transferred across the interface. The other options don’t capture the primary consequence: adhesion failure and its resulting cracking or separation.