Full-field settlement measurement at fresh cementitious material by digital image correlation

Abstract

Monitoring concrete properties at a very fresh state is essential to understand the different ongoing processes. Concrete undergoes strong displacements due to different processes such as, evaporation, water migration, settlement, formation of hydrates, shrinkage, early age cracking. This early state of concrete affects the long-term concrete performance. In the present paper the displacement distribution of fresh cementitious material from plastic state up to hardened state is studied by means of the optical and contactless method of DIC. The principle of DIC realizes a full-field 3D continuous monitoring of the surface displacement. An innovative technique of speckle pattern creation allows monitoring the surface displacement few minutes after casting of cement paste and mortar. The experimental results confirmed the effectiveness and correctness of the new technique giving a global overview much more representative than point measurements with traditional displacement meters.