Alkali-silica reaction expansions in high-performance and normal-strength cement grouts reinforced with steel and synthetic fibers

The role of brass-coated steel (BCS), hooked steel (HS), and polypropylene fibers in controlling the expansion and cracking in high-performance and normal-strength cement grouts is investigated. The grouts were prepared using the BCS, HS (from 0 to 2.0 vol.%), or polypropylene (from 0 to 0.30 vol.%) fibers. Standard prisms (25 × 25 × 300 mm³) were cast and cured for 40 days before subjecting to a special treatment to accelerate the alkali-silica reaction (ASR). Expansion measurements were taken for these prisms over an immersion period of up to 98 days, during which the extent of cracking was monitored. The results indicated a significant role of brass-coated and hooked steel fibers at volume fractions of 1.0 and 2.0% and polypropylene fibers at a volume fraction of 0.15% in reducing the expansion due to the ASR. The reduction in expansion of high-performance and normal-strength grouts was also dependent, in addition to the fiber type and content, on the duration of immersion of the grouts in a NaOH solution.Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 1, pp. 121– 130, January–February, 2005.