In order for concrete to have good strength and durability, proper vibration is required. If the concrete does not vibrate completely, honeycomb can form in the concrete, which can reduce the strength and durability of the concrete. Two methods are presented that can be used to check whether a honeycomb is formed depending on whether the concrete is fresh or hardened. For fresh concrete, where a metal ball of the same size as aggregate is placed on a concrete surface and the vibration time is observed until the ball is completely sunk, an impact echo test can be used to check whether a honeycomb is present. Based on concrete surface and strength tests, we showed that this method can be used to detect honeycomb.

• 이반(중앙대학교 스마트시티학과 박사과정) | van Jan Urbino
• 김동현(한국공항공사 항공산업연구원 선임연구원) | Kim Dong Hyun
• 조윤호(중앙대학교 사회기반시스템공학부 교수, 공학박사) | Cho Yoon Ho