ICC Recognizes Fiber Reinforced Concrete Value
January 24, 2012
The specifications and the codes recognize the value of Fiber Reinforced Concrete (FRC) versus the use of wire mesh.
The most significant, positive shift in the concrete-value of FRC over wire mesh is ICC’s International Residential Code specifications for residential slabs-on-ground which now explicitly requires that the wire mesh must be supported on permanent supports in the upper half of the slabs. This requirement along with ICC ES acceptance of Fiber Reinforced concrete as reflected in Acceptance Criteria 32, 208 and pending 383 have helped to increase the industries awareness, acceptance, and preference for FRC.
FRC Delivers Better Performance and More Value
The specifications and the codes recognize the value of FRC versus the use of wire mesh. Fibers deliver more performance at a lower in-place cost which is now more important than ever to both the engineers and contractors. The Ready Mixers have been a willing party in promoting the value of the FRC and today almost all Ready Mixers stock a variety of synthetic fibers for everyday use.
Without Supports, Wire Mesh Is Costly And Useless
Without supports, the wire mesh is lying on the ground.
Without supports, the wire mesh is still lying on the ground.
Without supports, the wire mesh is still lying on the ground, but now someone with a “J” hook is standing on the wire mesh and is trying in VAIN to pull it up into the concrete. Note: the guy with the “J” hook adds more dollars to the cost of the finishing crew.
RESULTS: If the wire mesh is not placed on permanent supports prior to the concrete being placed, the mesh will never stay in the concrete. As a result, the wire mesh is costly AND it contributes nothing to the concrete–useless; whereas the fibers are 3-dimensionally distributed and always on the job.
The Future of FRC
The growth of FRC has also meant increased activity in developing new and improved products. The first generation of synthetic fibers has been labeled microsynthetic fibers, which includes monofilament polypropylene and nylon fibers and fibrillated tape polypropylene fibers.
The new generation of synthetic fibers are labeled macrosynthetic fibers and for good reason. The length of the macros is a minimum of 1.5″ compared to 3/4″ for the micros and a minimum dosage rate of 3.0 pcy versus a typical maximum of 1.5 pcy for the micros. Besides the length differential, the other physical dimensions are mega-sized compared to the micros. Finally, the major difference is that no two macros are precisely the same as each manufacturer strives to achieve a better mechanical bond in the concrete.
Improving the mechanical bond is critical when the products are tested in a concrete matrix utilizing ASTM Test Methods C1609 or C1399. Both test methods are important in determining post-first crack toughness properties of the macrosynthetic fiber reinforced concrete.
ABC Polymer’s Role in the Future of FRC
The results of either of these tests help to determine the dosage rate required to meet a specific project or a state DOT specification. Thus it is important that the manufacturer trial and test all of the product properties that will yield a superior mechanical bond.
At ABC Polymer Industries we have developed numerous iterations of each of our Macrosynthetic Fibers: Macro-Pro™, Performance Plus DOT™ and our new FiberForce 650™ (Tuf Max DOT™). and invested in extensive testing to verify product performance. We have secured and continue to secure state DOT approvals for these products which have been used in several high-profile commercial/industrial projects.
ABC continues to work on improving the technical benefits of these products beyond post-first crack FRC applications.
ABC’s contribution to the future of FRC continues to expand as we help to drive the industry forward through our involvement in organizations including ACI, ASTM, NRMCA, FRCA, ASCE, and ICC.