Optical Fiber Methods for Measurement of Crack Width in TPB Concrete

Abstract

Concrete being a multi phase material is used widely in construction industry. It has high compressive strength and cost is less. But it is prone to cracking due to limited tensile strength. Parameters like  characteristic length, fracture energy G f  critical crack width w c  are used to understand cracks in concrete. One can estimate the crack width either by measurement of crack mouth opening displacement (CMOD/COD) or as crack tip opening displacement (CTOD). Though several non optical and optical methods exist, they fail to provide information on crack opening and crack width. The lattar is an important index  from durability point of view. To this end  the advantages of adopting optical  fiber methods over other and our findings in TPB  tests on pre-notched plain concrete samples  using optical fiber sensors and CMOD estimation will be presented. Their relative sensitivity and currents trends will be discussed.