Low-drying-shrinkage concrete containing carbon fibers

This paper provides a low-drying-shrinkage concrete (with fine and coarse aggregates) that is practically attractive when strength (compressive and flexural), flexural roughness, freeze-thaw durability, chemical attack resistance and cost are all considered. The use of short carbon fibers (just 0.19 vol %), together with silica fume, in concrete results in an 84% decrease of the drying shrinkage strain at 14 days of moist room curing; the shrinkage strain is just 1.9 x 10(-5) at 14 days. The fibers dominate the silica fume in lowering the drying shrinkage and increasing the flexural toughness. However, both fibers and silica fume contribute to lowering the drying shrinkage and increasing the flexural strength, toughness and freeze-thaw durability. On the other hand, the fibers decrease while the silica fume increases the compressive strength and chemical attack resistance, so the combined use of fibers and silica fume is recommended. The adverse fiber effects are associated with an air content increase.