Title: Twenty-Year Field Evaluation of Alkali-Silica Reaction Mitigation

Author(s): R. Doug Hooton, Chris Rogers, Carole Anne MacDonald, and Terry Ramlochan

Publication: Materials Journal

Volume: 110

Issue: 5

Appears on pages(s): 539-548

Keywords: alkali-silica reaction; chloride penetration; durability; field exposure; salt scaling resistance; supplementary cementitious materials

DOI: 10.14359/51685905

Date: 9/1/2013

Abstract:
To evaluate measures to prevent alkali-silica reaction (ASR) in concrete and to correlate short-term laboratory tests to long-term performance, an outdoor exposure site was established in Kingston, ON, Canada, in 1991. Alkali-silica reactive aggregate was combined into six concrete mixtures using various cements and supplementary cementitious materials (SCMs). Both unreinforced and reinforced 0.6 x 0.6 x 2 m (24 x 24 x 79 in.) beams, and 0.2 x 1.2 x 4 m (8 x 48 x 158 in.) pavement slabs were instrumented and have been monitored for 20 years. The high-alkali cement concrete cracked at 5 years and low-alkali cement cracked after 12 years. The high-alkali cement Wwas replaced with various amounts of SCMs. Two concretes, containing 50% ground granulated blastfurnace slag (GGBFS) and a ternary blend of 25% slag plus 3.8% silica fume interground with a high-alkali portland cement, have neither expanded nor cracked. After 14 years, cores were examined petrographically, chloride penetration profiles were made, and chloride diffusion as well as rapid chloride permeability tests, were performed.