Hydro-abrasive erosion of high performance fiber-reinforced concrete

High strength concretes are often used for increasing the erosion resistance of the hydraulic structures. Searching for possibilities of improving the resistance of the cement matrix to the aggressive environment action, like erosion or cavitation, is very often connected to introduction of various fibers into the matrix. This paper reports about an investigation of the erosion resistance of two types of high strength concrete used in hydraulic constructions, namely a high performance concrete (HPC) and high performance fiber-reinforced concrete (HPFRC). The HPFRC were made of three types of the fibers: steel fibers of 30 and 50 mm length and polypropylene fibers of 19 mm length. All the concretes were made using Portland cement (water to cement ratio was constant, w/c = 0.3), river sand, basalt aggregate, superplasticizer and silica fume. The hydro-abrasion–erosion resistance of concrete was evaluated according to ASTM C 1138 – underwater method. The analysis of the surface microstructure was performed using SEM photographs of fracture surfaces of the abraded HPFRC and by measurement of depth of wear damage by means of WMP ECLIPSE machine. In general, the erosion wear has depended on the contact zone: cement paste – aggregate and cement paste – fiber.