High performance fiber reinforced concrete – for repair in spillways of concrete dams

Hydraulic structures like spillways, glacis, etc. undergoes abrasion-erosion due to impact & cavitation losses due to the flowing water action. To overcome the deterioration of the concrete in such structures, addition of fibers to the concrete can be viable solution as it is known to increase the structural integrity of the concrete. A comparative study of various engineering characteristics using high strength concrete by incorporating steel fibers and micro polypropylene fibers has been carried out. Water/binder ratio of 0.23 has been kept constant for the study. Dosage for steel fibers are kept as 1, 1.25 and 1.5% by volume while for polypropylene fibers were kept as 1, 2 & 3 kg/m3. Engineering properties such compressive strength, flexural strength, toughness, energy absorption, splitting tensile strength, drying shrinkage, abrasion resistance, and water and air permeability of high performance concrete with & without fibers in its fresh & hardened state are investigated in this paper. Based on the study, the steel fibers with 1.5% dosage are found to be more effective in countering the abrasive and repetitive loading which can be more effective in the repairs of spillways and glacis of concrete dams.