Title:
Performance of Fly Ash Concrete in U.K. Structures
Author(s):
M. D. A. Thomas and J. D. Matthews
Publication:
Materials Journal
Volume:
90
Issue:
6
Appears on pages(s):
586-593
Keywords:
alkali-silica reaction; carbonation; chloride penetration; concrete structures; durability; fly ash; permeability; strength; Materials Research
DOI:
10.14359/4436
Date:
11/1/1993
Abstract:
Reports the findings of an investigation of existing concrete structures built using fly ash concrete. The structures include: two reinforced concrete road bridges, a reinforced concrete water-retaining structure, three mass concrete dams, a sea defense wall, and reinforced concrete foundation blocks. The age of the structures ranged from 2 to 33 years. In addition to fly ash concrete, comparable ordinary portland cement (OPC) concrete was available for sampling at all the locations chosen. Measurements of a range of properties were made on concrete cores taken from these structures. Generally, the fly ash concretes showed improved properties when compared with similar OPC concretes. These improvements include increased strength, reduced permeability, increased resistance to the ingress of chlorides, and suppression of alkali-silica reaction. Two-year-old concrete containing fly ash had carbonated to a greater extent than OPC concrete from the same structure, but differences were considerably less marked in older structures. Overall, these results indicate that the performance of the concrete in these structures was not adversely affected by the partial replacement of OPC by fly ash and, in many cases, significant improvements were observed.