The setting of concrete is a critical period to show phase change from fluid to solid state. The transition of phase makes it difficult to experimentally investigate the evolution of material properties such as elastic modulus and strength. Ultrasonic wave reflection technique is applied to probe the delicate samples, cement paste during the transition period, and the evolution of mechanical impedance is monitored. The growth of green strength of the samples are related to the mechanical impedance increase.

• 김재홍(울산과학기술대학교(UNIST) 도시환경공학부) | Kim, Jae Hong 교신저자
• 임홍재(경북대학교, 건설방재공학부) | Yim, Hong Jae