Assessing the performance of engineered cementitious composites under cyclic wetting and drying

Abstract

The application of electrical property measurements for assessing the permeation properties of Engineered Cementitious Composite (ECC) is demonstrated. To this end, a multi-electrode, two-point sensor was embedded within the surface region of two ECC specimens, with one being reinforced with the standard polyvinyl alcohol fibers and the other with no fiber reinforcement. These specimens were then exposed to cycles of wetting and drying in a laboratory environment. Electrical measurements were undertaken at regular intervals during this cyclic exposure regime, in order to monitor moisture movement within the surface region. It is shown that the multi-electrode sensor offers a simple, yet powerful, investigative technique for studying the spatial and temporal response of the surface region over an extended period of time and, hence, a comprehensive assessment of the protective qualities of this region. It is also shown that the proposed technique could be exploited to study the influence of surface cracking. A novel data presentation technique is introduced to facilitate visualization of key features during the cyclic testing regime.