Frost durability of high-volume fly ash concrete:relation liquid transport - damage

Abstract

Transport is central for frost deterioration, though playing different roles before/after starting freeze/thaw. Liquid uptake (LU) during rapid freeze/thaw in water (RF) and frost/salt test (FS) and relations LU-scaling and -internal damage were investigated on non- and air-entrained (AE) concrete (w/b = 0.29–0.45, 50–130 MPa). 8–22 % of the air-voids became waterfilled during water-curing. Absorption during pre-saturation in FS correlated to initial scaling but without general LU - salt scaling correlation. LU (kg/m2) was lower in RF than in FS, indicating different transport/damage mechanisms. In RF, LU correlated to cracking and scaling (especially well-cured concrete). Air entrainment always reduced LU. FS to −52 °C increased both LU and scaling for internally damaged concretes compared to −20 °C but did not affect LU in undamaged well-cured concretes. Modelled and measured LU during RF correlated very well and indicates hydraulic pressure is more important than cryosuction for reducing LU in AE concrete.