CRACKED AND UNCRACKED SHCC SPECIMENS UNDER DIFFERENT EXPOSURE CONDITIONS Suvash C. Paul (1), Gino Ebell (2), Gideon P.A.G. van Zijl (3) and Wolfram Schmidt (4) (1) and (3) Department of Civil Engineering, Stellenbosch University, South Africa (2) and (4) BAM Federal Institute for Materials Research and Testing, Germany Abstract This paper describes the fibre-reinforced strain hardening cement-based composite (SHCC) performance under various exposure conditions. Cracked and uncracked SHCC beam specimens were subjected to cyclic wetting and drying under chloride exposure to observe the time of depassivation and corrosion potential of the imbedded reinforcement. Two reference mortars, one of the same strength class as the SHCC (Mortar 1) and the other of high strength class (Mortar 2) were used under the same conditions. Finally, tests for determining the rapid chloride migration coefficient, electrical resistivity, capillary water absorption and freeze- thaw were also performed to observe the corrosion probability and diffusion rate in uncracked SHCC and mortars. 1. INTRODUCTION Current knowledge about strain hardening cement-based composite (SHCC) indicates that the mechanical behaviour of this material is suitable for improving structural performance due to fact that it has higher tensile and flexural strength, ductility and most importantly, lower average crack widths than normal concrete (Li et al. 1995, Paul and van Zijl 2013). Lack of information on the long term durability behaviour of SHCC remains a major obstacle in designing durable concrete structures with this modern construction material. Different durability tests such as the accelerated corrosion test, the chloride penetration test and the capillary water absorption test were performed on SHCC by various researchers over the past few years. So far, in terms of durability, researchers have found better performance of SHCC over the reference concrete used in their research work, as recently reported by van Zijl and Wittmann (2011). In this work, SHCC performance was observed under various exposure conditions, namely chloride-induced accelerated corrosion in cracked and uncracked specimens, rapid chloride migration (RCM), electrical resistivity (ER), capillary water absorption (CWA) and the freeze-thaw testing of uncracked specimens. For comparison, two mortars were also used under the same exposure conditions and their performances were compared with the SHCC performance. The material composition, as well as fresh and hardened characteristics are summarised in Tables 1 and 2. 2. MATERIALS AND METHODS OF TESTING Corrosion potential of reinforced SHCC (R/SHCC) and R/mortar was studied on a total of 16 beam specimens measuring 100 x 100 x 500 mm. For the uncracked reinforced specimen corrosion test 2 specimens of each material type (thus a total of 6) were used. In addition, 6 6+&&ｱUG,QWHUQDWLRQDO5,/(0&RQIHUHQFHRQ6WUDLQ+DUGHQLQJ&HPHQWLWLRXV &RPSRVLWHVｱ1RYHPEHU'RUGUHFKW7KH1HWKHUODQGV