Title: Performance of Cracked High-Performance Concrete in a Harsh Marine Environment

Author(s): Edward G. Moffatt, Andrew Fahim, and Herwing Lopez-Calvo

Publication: Web Session

Volume: ws_S18_PeformanceCracking_Moffatt.pdf

Issue:

Appears on pages(s):

Keywords:

DOI:

Date: 11/16/2018

Abstract:
This paper presents the long-term durability performance of cracked concrete containing silica fume and various levels of fly ash, and corrosion inhibiting admixtures exposed to a harsh marine environment for 9 years. Eighteen reinforced concrete prisms (100 x 150 x 1200 mm [3.9 x 5.9 x 47.2 in.]) were placed at the high-tide level at Treat Island, Maine in order to study their resistance to corrosion. The specimens included mixtures with various fly ash contents (0, 20 and 40%) incorporating two commercially available corrosion-inhibiting admixtures (disodium tetrapropenyl succinate and calcium nitrite at 5 and 12.5 L/m3, respectively). All concrete mixtures were cast using a CSA Type GUb-8 (ASTM Type I) cement with 8% silica fume. A water-to-cementitious ratio between 0.37 and 0.42 was used. A crack of approximately 0.25 mm (1/100 in.) was achieved in the tensile region of each beam using a stainless-steel loading frame, as shown in Figure 1. Testing included the determination of compressive strength, bulk electrical resistivity, chloride penetration and electrochemical corrosion monitoring. Chloride penetration results in accordance with ASTM C1556 showed a marked reduction in diffusion coefficient in concrete containing fly ash with respect to the control (0% fly ash). A similar trend was observed in concrete containing disodium tetrapropenyl succinate. The performance of such systems is also highlighted by electrical resistivity and electrochemical measurements. Electrochemical corrosion monitoring showed an improved performance on the corrosion propagation in concrete containing fly ash and corrosion inhibiting admixtures.