Defects in Concrete and its Causes - Honeycomb

Honeycomb is a condition of irregular voids due to failure of the mortar to effectively fill the spaces between coarse aggregate particles. Where bridging of the aggregate particles or stiffness of the mixture is a cause of honeycomb, vibration may assist in overcoming the bridging by increasing the flowability of the concrete.



Factors that may contribute to honeycombing are: 

• congested reinforcement, 
• insufficient paste content, 
• improper sand-aggregate ratio, 
• improper placing techniques, 
• quick setting on hot concrete, and difficult construction conditions. 

Changes in mixture proportions to improve workability may assist in reducing or preventing honeycombing.