Performance of bitumen protective coatings for buried concrete

Abstract

Following the discovery in the late 1990s of seriously damaged M5 motorway bridge foundations due to thaumasite formation, the standards for buried concrete were changed. Binder types and mix designs to resist aggressive ground conditions are specified; however, in highly aggressive conditions it may be necessary to utilise additional protective measures including surface coatings to ensure the survival of buried concrete structures. Such measures may also be used to prevent deterioration of concrete of lesser specification than would be required for a particular ground aggressivity. The paper presents results from a long-term laboratory-based study in which concrete cubes of high susceptibility to thaumasite attack, with and without bitumen coatings, were exposed to sulfate-rich solutions at 4·5°C for 5 years. Moreover, concrete prisms of the same concrete and three others of different susceptibilities to attack, each with one bitumen-coated face, were buried in pyrite-bearing clay for 9 years, at 4·5°C. All types of concrete tested suffered significant attack, whereas the bitumen coating, even if damaged, proved successful in preventing deterioration of even the most vulnerable concretes. The paper concludes with a brief discussion of the potential benefits of using coatings for the protection of buried concrete.

Badania nad odpornością powłok ochronnych dla betonu na działanie wilgoci atmosferycznej

“…Supplementary cementitious materials, including ultra-dispersed mineral additives, are used to improve the quality of concrete [10,11]. Methods that prevent the occurrence of corrosion by covering the surface with protective materials or creating artificial waterproofing are also effective [12][13][14][15][16].…”

Editorial

“…In their paper, Abubaker et al (2017) investigate the performance of bitumen protective coatings for buried concrete. Controlling concrete deterioration in situations where concrete is exposed to chemically aggressive conditions with the result that the long term performance and safety of a structure is at risk is of great importance.…”

“…The damage caused by thaumasite sulfate attack (TSA) has been well documented. Abubaker et al (2017) undertook a series of long term investigations where specimens were exposed for a five test period. According to their analysis, Abubaker et al (2017) concluded that bitumen surface coatings appear to provide an effective way of preventing TSA damage in concrete.…”

“…Abubaker et al (2017) undertook a series of long term investigations where specimens were exposed for a five test period. According to their analysis, Abubaker et al (2017) concluded that bitumen surface coatings appear to provide an effective way of preventing TSA damage in concrete. However, the authors advise caution as the reliability of protective coatings is highly dependent on the integrity of the coating.…”

Editorial

“…The general issues have included papers on materials as diverse as cooking oil (Vu et al, 2017), foam insulation (Densley Tingley et al, 2017), epoxy resin-soil-cement mixtures (Anagnostopoulos, 2017), Timber (Foster and Ramage, 2017), sugarcane bagasse bricks (Madurwar and Ralegaonkar, 2017) and bitumen coatings (Abubaker et al, 2017), as well as a range of contributions covering concrete, cementitious mortar and related materials and a book review relating to centrifuge monitoring for civil engineers.…”