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Abrasion erosion damage of concrete structure

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A concrete structure that is transporting water with salt, sand, and rock will be subjected to grinding action, which causes concrete surface erosion. Stilling basins(is a structure to dissipate the flow energy at the toe of the spillway) of dam’s experiences abrasion damage if the flow didn’t sweep out the debris. Some stilling basins with faulty flow patterns pull downstream sand and rocks to upstream into the basins. These materials retained in basins, and it will cause abrasion damage during periods of high flow. 


The abrasion damage caused by the grinding action of silt, sand, and rock. The grinding action will remove the concrete surface and expose the aggregates in some cases. The aggregates will be polished due to grinding action. The severity of abrasion erosion damage will depend on different factors such: exposure time to grinding action, the shape of concrete structure, flow velocity and pattern, flow direction. In general, it is difficult to anticipate the performance of concrete under these conditions. Hydraulic studies shall be conducted for abrasion-erosion damaged concrete structures to determine the flow conditions and patterns that exist on a concrete surface and evaluate the modification required to eliminate the concrete damage due to abrasion erosion. If the cause of abrasion-erosion damage didn’t eliminate, the concrete would suffer abrasion-erosion damage again. 
Figure 1


Concrete with higher quality and compressive strength will possess a higher resistance to abrasion-erosion damage compared to lower concrete quality. Studies have shown that the silica fume will significantly improve concrete abrasion resistance. Also, the use of polymer concrete will enhance concrete abrasion resistance. If the damage does not extend behind reinforcing steel, the silica fume concrete should be placed over a fresh epoxy bond coat. Figure no:2 shows the application of silica fume concrete to an area of abrasion, erosion, and freeze-thaw damage on the floor of a Dam spillway.
Figure 2


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