Nycon-PVA macro, micro fiber blend toughens slabs

A scrap recycling plant manager approached Nycon Corp. to design a robust slab that would reduce the cost and frequency of replacing concrete in its heavy work area. The operation needed heavy-duty slabs capable of enduring tremendous abuse as well as occasional 200,000-lb. wheel loads.

The facility runs 24/7, so the new slabs needed to be ready for traffic in less than one week. The plant manager also wanted slabs with high abrasion resistance and an increased service life to avoid disruption to the operations and improve return on construction investment.

The solution was Nycon’s Tuff-Slab, whose design measures up to 18-in. thick, incorporates steel rebar near the bottom of the slab, and uses dowelled construction joints. The Tuff-Slab mix is a high performance concrete made with a blend of Nycon-PVA fibers that requires rapid placement, timely cut control joints and proper curing.

The recycling plant’s first Tuff-Slab installation was a 40,000-sq.-ft. scrap pad, including a test slab that was mixed, poured and opened to heavy test traffic two days after placement. The latter slab was only 3.5-in. thick and placed without any wire mesh or rebar. The Tuff-Slab mix attained 5,000 psi in seven days and 7,000-plus psi in 28-days, and included a blend of Nycon-PVA RF4000 (macro fiber) at 6 lbs./yd. plus Nycon-PVA RSC15 (micro fiber) at 3 lbs./yd. Independent laboratory testing on cylinders, beams and panels made to compare a normal concrete versus Tuff-Slab mix confirm a doubling of impact and abrasion resistance, plus dramatic reduction in premature failure when specifying the performance product.

Nycon-PVA is the only fiber that develops a molecular bond to concrete, which is activated when the PVA comes into contact with the mix alkalinity. The fiber’s unique molecular bond to the cement paste provides improvement to the concrete’s abrasion and impact resistance, without any loss of compressive strength. The new Tuff-Slab has exhibited no cracks, displacement or deformation since being placed in service at the scrap recycling operation in November 2011. — 800/456-9266;