Transverse strain sensitivity of steel fiber reinforced cement composites tested by compression and split tensile tests

Abstract

The use of cement based composites as strain sensors have been studied by different researchers. The effect of “cross talk” for which the strain is perpendicular to electric current in the cement based composite, is an important issue for using the cement based material as a strain sensor. In this study, steel fiber reinforced cement matrix composite was tested with two different compression tests, at which compressive strain and electric current were parallel or perpendicular. The “cross talk compression test” at which electric current and compressive strain was perpendicular has been conducted for the first time in this study. Also, split tensile tests at which tensile strain and electric current were parallel or perpendicular were applied for the first time in this study. The cross gage factors were higher than the gage factors which were explained by mechanisms on variations of electron transfer cross sections. Strong linear relationships between the perpendicular compressive strain–electrical resistance change (%R) and perpendicular tensile strain–electrical resistance change (%R) were obtained. These strong linear relationships can be used to decompose the effects of “cross talk” in cement based sensor applications.