CHARACTERIZATION OF TENSILE BEHAVIOR IN UHPFRC THIN SLAB USING NDT METHOD AND DIC SYSTEM

Proper test and analysis methods are necessary for characterizing the tensile behavior of strain hardening Ultra High Performance Fiber Reinforced Cementitious Composites (UHPFRC) accurately and representatively. In this paper, the direct tensile tests (DTT) is applied, and all 5 structural specimens are extracted from a thin slab, representing UHPFRC layers covering large areas such as bridge decks and slabs or thin elements. Before processing the slab, the non-destructive test (NDT) using magnetic probe is applied to detect the local fiber content and orientation distribution of each specimen, and sequentially, predicting the tensile strength individually. For DTT, each specimen is strengthened on both ends using aluminum plates, and built-in the testing machine. By means of digital image correlation (DIC) system, the development/distribution of multiple micro-cracks and fictitious cracks of UHPFRC can be investigated visually and the propagation of each fictitious crack can be monitored from early formation until final failure.