Linseed oil-based concrete surface treatment for building and highway structures in Hong Kong

Abstract

This experimental program investigated the effectiveness of concrete surface treatment using four Canadian linseed oil-based sealants on concrete specimens made from G30/20 and G45/20 concretes, which are typically used for building and highway structures in Hong Kong. The tests were conducted at the University of Hong Kong and the University of Manitoba independently, using samples cast from the same mixes in Hong Kong. A total of more than 500 specimens were tested in each university for salt spray resistance, carbonation, bond strength, dripping and ultra-violet weathering. The results show that the four sealants were capable of penetrating through vertical, upward horizontal and downward horizontal concrete surfaces up to depths of 2.5 mm. All the four sealants significantly enhanced the resistance of G30/20 concrete against salt spray attack and carbonation. The resistance of G45/20 concrete to salt spray was also increased. Up to a duration limit of 500 hours of quick ultra-violet weathering, the treated specimens still demonstrated higher resistance against salt spray attack and carbonation than the untreated ones. However, no conclusion can be made regarding the effect on carbonation resistance of G45/20 concrete, since both the treated and untreated specimens showed no signs of carbonation after the test.