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TECHNICAL PAPER

Without corrosion After 2-d accelerated corrosion After 4-d accelerated corrosion

FRC 1

(a) (b) (c)

FRC 2

(d) (e) (f)

FRC 3

(g) (h) (i)

eCC

(j) (k) (l)

Figure 7: Typical failure mode of R/FRCs and R/ECC prism specimens subject to 4-point bending before and after 2-d and 4-d accelerated corrosion.

4. CoNCLUSIoNS to a ductile failure behavior subject to corrosion-induced steel
reinforcement expansion. The superior confinement provided by
This paper evaluates the influence of passive confinement from
the cover material on the corrosion of steel reinforcement. the ECC cover significantly slows down the corrosion rate and
Damage pattern of cover material, mass loss and mass loss mass loss of the steel reinforcement.
rate of the steel reinforcing bar, and residual flexural strength
and failure mode of reinforced prism specimens after corrosion ACkNoWLEDGEMENTS
were investigated. Results showed that increase of fibre content The authors would like to acknowledge financial support from
in FRC cover moderately improves the corrosion performance AcRF Tier 1 (RG52/12), Ministry of Education, Singapore and the
and the efficiency of fibre addition reduces with growing fibre CREATE SinBerBEST program, National Research Foundation,
dosage. However, R/ECC showed significant performance Singapore.
improvement with reduced mass loss and mass loss rate of steel
reinforcement and increased residual flexural load capacity. This REFERENCES
phenomenon highlights fibre dosage in cover material alone [1] Bazant, Z. P., Physical model for steel corrosion in concrete
is not the dominating factor of corrosion resistance; rather the sea structures–theory, Journal of Structural Division 105 (6)
fundamental change of failure mode of cover material from (1979) 1137–1153.
brittle to ductile is the key to enhance the corrosion resistance
in R/C. The high ductility and damage tolerance together with [2] Angst, U., Elsener, B., Larsen, C. K., Vennesland, O., Critical
the self-controlled tight crack width of ECC alter the brittle chloride content in reinforced concrete- a review, Cement
failure mode of the conventional concrete or FRC cover material and Concrete Research 39 (12) (2009) 1122–1138.

16 The IndIan ConCreTe Journal | deCember 2019