Properties of Reactive Powder Concrete

Composition

• Concrete is a mixture of cement, aggregates such as gravel and sand, additives and other fibers or materials. Each project calls for a specific concrete mixture that suits construction needs. The strength of concrete is necessarily more for a bridge than for a driveway. A bridge will require ultra-high-performance concrete to be able to span long distances without shearing and crumbling. RPC is carefully engineered with each component of cement, aggregate and additives refined to be ultra-high-performing. Fine steel fibers and sand are mixed with the finest Portland cement. Unlike traditional concrete, RPC has no aggregates larger than fine sand.

Compression Strength

• Compression strength is the ability of a material to stand up under applied pressure. RPC compression strength can be as high as 120,000 pounds per square inch (psi) compared to residential strength of 2,500 psi. High-strength concrete has a psi above 6,000, and concrete in high rise buildings may have a compressive strength of 20,000 psi, according to the Portland Cement Association.

Tensile Strength and Ductility

• Tensile strength is the ability of a material to hold together as it is pulled from each end. Because of the fine steel fibers distributed throughout RPC, the ductility of the concrete is improved, making it less brittle and less vulnerable to breaking when tension is applied. This feature of RPC will come into play as supporting members of an elevated slab of RPC flex and move, putting tension on the slab longitudinally.

Shear Strength

• Regular concrete snaps off easily when pressure is applied, indicating a low shear strength. Low shear strength is a result of a lack of flexibility that makes a material as brittle like a pretzel stick. Steel reinforcement fibers give flexibility to RPC, allowing for greater spans with fewer supports. Because of the ultra-high strength, increased flexibility and tensile strength of RPC, less concrete is used, making for lighter slabs. Lighter, stronger materials are a benefit to architectural and civil engineering construction, as they allow longer, safer bridges and taller buildings.