Which component can increase the ability of a concrete structure to withstand tensile forces?

The ability of a concrete structure to withstand tensile forces is significantly enhanced by the incorporation of rebar, or reinforcing steel bars. Concrete is inherently strong in compression but weak in tension, meaning it can easily crack or fail when pulled or stretched. Rebar is embedded within the concrete to compensate for this weakness.

When tensile forces are applied to a concrete structure, the rebar takes on the tensile load, effectively preventing cracks from forming and providing stability. The combination of concrete, which handles compressive stress well, and rebar, which excels in tensile strength, results in a composite material that can withstand a variety of forces and stresses during its use.

While other materials listed, like plywood or gypsum board, serve different purposes in construction, they do not improve tensile strength within concrete structures. Steel cables serve a similar function but are often utilized in specific applications such as tensioning or suspending structures, rather than being integrated into the concrete mix like rebar.