FAQs

A "plain concrete slab" on ground uses only the concrete to support the design load. (A plain concrete slab uses the flexural strength of the concrete and the depth or thickness of the slab to support the anticipated load.) Secondary/temperature-shrinkage reinforcement is used to control cracks after they have formed in the cross-section. Secondary reinforcement does not contribute to the load carrying capacity of the slab. Until the introduction of discrete fibers, welded-wire fabric (WWF) had been typically specified as secondary/temperature-shrinkage reinforcement. However, as most engineers know, unless properly placed, there is virtually no benefit to this technology. And, as most engineers never require the use of supports with WWF, it ends up on the ground not in the concrete.

The benefits of using Nycon fiber in "plain concrete slabs" are significant. Nycon FRC slabs have been shown to have fewer cracks, greater impact resistance, lower permeability and superior long-term durability. With Nycon fibers always uniformly distributed in the concrete there is no question as to whether the secondary reinforcement will perform because of improper placement, as is typically the case with WWF.

The thickness of the plain concrete slab is determined by the properties of the design mix and the load carrying requirements of the concrete used in the slab. ACI 302 Guide for Concrete Floor and Slab Construction, ACI 330 Design and Construction of Concrete Parking Lots, and ACI 360 Design of Slab on Grade are used to design this type of slab. Plain concrete slabs will be thicker than structural slabs but in most cases are more cost effective compared to structural slabs.

Typically highways and parking lots, along with most industrial and commercial floors, are "plain concrete" slabs.