Concrete Masonry Bridges Steel Fibers, Item SPV.0035.XX.

A Description

This special provision describes furnishing and adding steel fiber reinforcement to the superstructure concrete. All work shall be in accordance with section 502 of the standard specifications and as hereinafter provided.

B Materials

Add continuously deformed or Z-hooked end deformed steel fiber reinforcement conforming to ASTM 820 type I or type II to the superstructure concrete. Add the steel fibers to the concrete mix at a dosage rate of 80 lbs/CY (47 kg/m3). The steel fibers shall meet the following requirements:

·  Nominal length of 1.5 inches (38 mm);

·  Aspect ratio of 50 to 60; and

·  Certified to meet the minimum tensile strength requirements of ASTM 820.

Potential sources for the low carbon steel fibers specified above include, but are not limited to: Bekaert Steel Corporation, Atlanta, Georgia, 770-421-8520; Fibercon International, Inc., Evans City, Pennsylvania, 1-800-521-9908; and Synthetic Industries, Chattanooga, Tennessee, 1-800-635-2308.

If necessary for workability, the following adjustment for steel fiber reinforced concrete may be made to the total aggregate gradation limits specified in the article QMP Concrete Structures of these special provisions: The percent of total aggregate finer than the #4 sieve (4.75 mm) shall not exceed 52 percent by weight.

For all steel fiber reinforced concrete masonry in the bridge superstructure, modify the article QMP Concrete Structures of these special provisions as follows:

1. Use Grade C-FA, C-S, C-IP or C-IS concrete with a minimum cement content of 660 lbs/cy (392 kg/m3).

2. For calculating the compressive strength percent within limits (PWL) of subsection H.2, use a specification lower quality limit (L) of 5000 psi (34.5 MPa).

C Construction

Add the steel fibers to the truck mixer during or after charging the drum with the other concrete mixture components. Add the steel fibers by belt or manually while the drum is turning at mixing speed. Mix the concrete adequately to ensure uniform distribution of fibers prior to incorporation of the concrete into the work.

A knowledgeable technical representative of the steel fiber manufacturer shall attend as a minimum the pre-pour conference and the first day of deck placement. This technical representative shall provide the contractor and the ready-mix producer with all advice and troubleshooting expertise necessary to achieve proper mixing, delivery, placement, and finishing of the steel fiber reinforced concrete masonry.

D Measurement

The department will measure Concrete Masonry Bridges Steel Fibers by the cubic yard acceptably completed, in accordance with subsection 502.4.2 of the standard specifications.

E Payment

The department will pay for the measured quantity at the contract unit price under the following bid item:

ITEM NUMBER / DESCRIPTION / UNIT
SPV.0035.xx / Concrete Masonry Bridges Steel Fibers / CY

Payment shall be in accordance with subsection 502.5.2 of the standard specifications, and includes furnishing all labor, tools, equipment, materials, and incidentals necessary to complete the contract work.

07/05

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