Durability evaluation of PP-ECC with local superfine sand (SSPP-ECC) serviced in seasonal frozen region

Abstract

The recently developed engineered cementitious composites with local superfine sand and polypropylene fiber (SSPP-ECC) has been proved to be a kind of high ductility and toughness material with wide applicability. In view of the durability challenges to concrete structures serviced in seasonal frozen region, a series of experiments including the carbonation, freeze–thaw, coupling of carbonation and freeze–thaw, coupling of salt solution and freeze–thaw, chloride ion penetration resistance and impact resistance tests of SSPP-ECC and normal concrete were carried out to fully evaluate their durability and environmental adaptability. The test results showed that SSPP-ECC is significantly superior to normal concrete in frost resistance, and can more effectively resist the coupling effects of carbonation and salt solution on freeze–thaw, so that the specimens can maintain higher levels of integrity, dynamic elastic modulus and flexural strength. The resistances of SSPP-ECC to carbonation and chloride ion are also better than that of normal concrete, and the SSPP-ECC specimens showed ultra-high toughness under repeated impact load, while the normal concrete specimens showed obvious brittle failure. Furthermore, the comprehensive evaluations on durability of SSPP-ECC and normal concrete were in terms of fuzzy analytic hierarchy process, and it was concluded that SSPP-ECC is more durable than normal concrete suffered to multiple adverse environments, especially when serviced in seasonal frozen region.