Have you ever been walking alongside a river and noticed large rocks armouring the shoreline? This is what’s known as rip rap. No, it’s not the latest dance craze; these blocks of stone or concrete protect our coasts from scour and erosion. Without rip rap, the strength of bridges can become compromised, roadways can wash out, and properties can be irreparably damaged. Rip rap might seem simple, but the science and aggregate equipment involved behind the scenes is quite complicated. So, we’ve put together a quick and handy guide to rip rap and the equipment it involves. If you have any questions about rip rap, aggregate equipment or anything aggregate-related, contact the experts at Sepro Aggregates—we’d be happy to help!

Waterways And Erosion

River erosion is one of the most powerful landscapes on the planet. Rivers can shape rock in three main ways: hydraulic action, dissolution, and abrasion. 

Hydraulic action happens when the friction of flowing water erodes soft rock. Flowing water picks up sediments and transports them downstream. 

Dissolution happens when acidic water erodes rocks in a stream. This process usually happens over an incredibly long period of time and affects certain types of rock, like limestone, more than others. 

The last process, abrasion, is the most effective erosive force of a river. Abrasion happens when flowing water picks up large pieces of bedload and thrashes them around a riverbank, knocking more and more sediment, gravel, and pebbles loose. These pieces are then carried away by hydraulic action and can be deposited in other areas downstream. 

These processes can also happen on coasts. Waves crash along the shoreline, break down rocks, knock them into each other, and then pull them back out into the ocean. Without properly installed rip rap, our coasts and riverways would erode much, much quicker due to these forces.

How Rip Rap Works

Rip rap is placed along the shores of rivers and oceans to prevent erosion, stabilize slopes, and provide structural support. Rip rap does this through a combination of the size, shape, weight, and durability of the rocks it uses. 

Rip rap along a riverbank

Rocks used for rip rap should be blocky, angular, and have flat, clean edges. The sharp edges help the rip rap lock together, creating a strong resistance to water flow. Soft riverbanks that would usually break down quickly due to fast-flowing rivers can last for years without changing thanks to properly installed rip rap. 

How Rip Rap Is Created

Since rip rap shape and size are critical for shoreline protection, the right combination of grizzly feeder, chutes and engineering design needs to be used to create it. A portable rip rap plant, housing a Sepro 64” x 24’ HR Grizzly Feeder, offers increased versatility for aggregate producers looking for mobile solutions. 

Once the aggregate material has been sorted, it can be transported to the worksite. The bank slope, thickness of rip rap layers, toe treatment, and other calculations need to be made to optimize protection and strength. With proper installation, our riverways, boardwalks, and coastal cities are well protected from water’s erosive forces. 
Sepro Aggregates has built portable plants for rip rap production, rock crushing, and coarse aggregate sorting. We help our clients reach their target goals while coming in on budget. To learn more about our portable plants and aggregate equipment, contact us today.