ATP has developed a new production technology for the production of the stirrup where we do not bend a straight rebar to create a stirrup, but instead directly produce the bent or closed stirrup as a final product. Closed stirrups allow better confinement of concrete and the smaller radius enables the reinforcement to be closer to the surface to increase the total mechanical
characteristics of the concrete structure. Fiberglass stirrups are made from E-glass polyester
resin with improved external surface adherence created without milling or other processes that involve removing materials and/or reducing the resistant section.

WHY CLOSED STIRRUP?
Differently from the “bent” rods, ATP Closed Stirrups provides firm solution to keep the orientation of the reinforcement with high mechanical characteristics also in the curved zone of the stirrup.

BETTER CONFINEMENT OF THE CONCRETE

SMALLER RADIUS
Get the reinforcement closer to the surface to increase the total mechanical characteristics of the concrete structure.Better structural integrity (Bolt) With closed stirrup there is an higher punching resistance where the anchors are installed.

Better structural integrity (Bolt) With closed stirrup there is an higher punching
resistance where the anchors are installed.

DESIGN TENSILE & MODULUS PROPERTIES

Tensile and Modulus Properties are measured per ASTM D7205-06, Standard Test Method for Tensile Properties of Fiber Reinforced Polymer Matrix Composite Bars. The ultimate tensile load is measured and the tensile modulus is measured at approximately 10% to 50% of the ultimate load. The slope of the stress-strain curve is determined as the tensile modulus. Ultimate Strain is extrapolated from the ultimate load divided by the nominal area and modulus. The area used in calculating the tensile strength is the nominal cross sectional area. The “Guaranteed Tensile  trength”, f* fu is as defined by ACI 440.1R as the mean tensile strength of a given production lot, minus three times the standard deviation or f* fu = fu,ave – 3.