Silica Fume Treatments as Means for Improving Durability of Glass Fiber Reinforced Cements

Abstract

Treatments with silica fume slurry were applied to improve the durability of alkali resistant (AR) glass fiber reinforced cement composites (GFRC). Two treatments were studied: fiber treatment obtained by immersion of the reinforcing strand in the slurry, prior to their incorporation in the composite, and matrix modification of the matrix by replacing with 10% silica fume. Fiber treatment alone was found to be extremely effective, leading to 50% or more toughness retention after 5 to 9 months of accelerated aging. Additional modification of the matrix led to better performance, with the toughness retention exceeding 50%. Matrix modification alone did not yield any significant improvement. The effects of the silica fume treatments were discussed in terms of the microstructural and chemical aging mechanisms.