Mechanically Induced Cracking Behaviour in Fine and Coarse Sand Strain Hardening Cement Based Composites (SHCC) at Different Load Levels

This research paper describes the development of strain hardening cement based composite (SHCC) with mostly local ingredients available in Stellenbosch, South Africa, and subsequent characterisation of crack distributions under various loading conditions. The mechanical induced cracking behaviour of SHCC containing local coarse sand (CS) (particle size up to 2.36 mm) is reported and compared with SHCC containing specially graded local fine sand (FS) (particle size up to 300 m). Crack width distributions, obtained by digital image correlation, in direct tension at various average strain levels are presented for both FS and CS-SHCC dumbbell specimens. Both these SHCC types were also used to prepare beam specimens, both unreinforced and reinforced with steel bar at two reinforcement levels and with three cover depths. Both sand types could be used successfully for SHCC, achieving strain hardening and crack width and spacing control.