Bug Holes in Off-Form Concrete

CAUSE:

Entrapped air bubbles which fail to rise to the surface - particularly in low water:cement ratio concretes - will appear as ‘bug holes’ on the surface of the off-form concrete.

PREVENTION:

Surface imperfections in precast, prestressed and/or poured in situ concrete can be significantly reduced or eliminated through the use of MasterFinish® 211, a ready-to-use, water-based, non-toxic surface consolidation agent. MasterFinish® 211 provides easy and complete release when applied to most types of form and/or form liner.

REPAIR:

Surface repairs can be made with MasterEmaco® N 5100 or Sika MonoTop FC, which are concrete-grey, ready-to-use mortars, based on hydraulic binders and high-grade quartz sands, modified with synthetic polymers. MasterEmaco® N 5100 and Sika MonoTop FC contain no chlorides or other salts that may cause corrosion or efflorescence (blooming). To repair bugholes where a structural material is required use Sika MonoTop 723.