Durability Properties of Sprayed Engineered Cementitious Composite

Engineered cementitious composite (ECC) shotcrete is a sprayable cement composite reinforced with synthetic fibers that exhibits a strain-hardening characteristic under tension. The ductile behavior of ECC makes it an ideal repair material for concrete structures as tensile strains from expansion of the original concrete structure can be accommodated. The aim of the reported research was to develop an ECC mixture design having superior durability properties while exhibiting a strain-hardening characteristic. Six mixture designs of ECC and a 5800 psi (40 MPa) cast-in-place concrete were tested using four test methods to determine their chloride resistance. Results from bulk diffusion testing showed that the most effective ECC mixture design, which incorporated a metallic soap additive, showed a 90% reduction in the chloride diffusion coefficient when compared with a 5800 psi (40 MPa) cast-in-place concrete. The alternating current (AC) resistivity, void, and sorptivity tests conducted did not show a strong correlation to the bulk diffusion test.