Experimental Investigation of Failure behavior of Reinforced ECC Beams in Flexure

Abstract

this paper is based on the experimental investigation of failure behavior of larger size steel reinforced
Engineered Cementitious Composite (R/ECC) beams in flexure. A typical mix of ECC known as M45 with Polyvinyl
Alcohol fiber content of 2% has been modified by reducing fiber content to 1.5% by volume and water to binder ratio
was increased from 0.25 to 0.33, in order to lower the compressive strength of PVA-ECC up to 33MPa. Failure behavior
of R/ECC beams in flexure is compared with normal RC beams having same dimensions, steel reinforcement and
compressive strength of concrete. R/ECC beams showed an improved performance in flexure under similar loading
conditions as compared to RC beams and maintained greater load carrying capacity even after cracking thus absorbing
greater energy after yield point. This might be due to the bridging effect of fibers in ECC at micro-structure level where
PVA fibers played role in transmitting stresses across the cracks and resisted the applied load. Cracking pattern of
R/ECC observed was different than RC beams as cracks in R/ECC were more in number and closely spaced while
maintained smaller opening size. While in RC beams a typical Griffith crack pattern was observed. R/ECC beams
performed better than RC beams in terms of energy dissipation under the given conditions and proved to be capable of
being used in critical elements with higher energy dissipation requirements.