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ABC Polymer Industries (www.abcpolymerindusties.com) has developed three macrosynthetic fibers, each exhibiting its own well-defined engineering properties in the concrete composite.

Fibril Tuf, a microsynthetic, fibrillated polypropylene fiber, is designed to optimize the mechanical bond between the concrete mortar matrix and the fiber networks.

Fibril Tuf has been tested using the consensus test methods required in ICC ES Acceptance Criteria 32, the single consensus acceptance criteria in the WORLD for evaluating synthetic fibers. Fibril Tuf meets or exceeds all of the AC32 criteria for use as plastic shrinkage crack reinforcement and temperature-shrinkage crack reinforcement.

FRC- Ready Mixer Profit Center

Since Fiber Reinforced Concrete (FRC) is growing in popularity with the engineers and contractors, as well as, referenced within a growing number of project specifications and codes, the Ready Mixer should present and promote the concrete fibers along with the concrete admixtures and additives. Fibers are a Ready Mixer Profit Center!

Why Codes and Specifications Recognize Fibers’ Benefits

With an increasing number of specifications and codes recognizing the use of fibers as plastic shrinkage crack control and temperature-shrinkage crack control reinforcement in concrete rather than wire mesh, the Ready Mixer needs to be able to provide the products required by these specifications and codes.

In those states, counties, municipalities, townships and other smaller governed entities where the ICC International Residential Code is recognized as the controlling building code there has been a modification to the secondary AND the temperature-shrinkage reinforcement specification. The specific reference is IRC Subsection 1909.3 Joints Slabs-on-Ground. herein the code talks to the use of both microsynthetic fibers and wire mesh in residential slabs-on-ground.

It is the building/construction department engineer’s responsibility to select the material that will best meet the needs of the agency in terms of ‘value engineering’ and local conditions. Criteria must be established to ensure that the materials selected provides the end results required.

ICC ES AC32 provides the best acceptance criteria for Microsynthetic Fiber as both secondary/temperature-shrinkage reinforcement and plastic shrinkage cracking reinforcement. Both are addressed in Subsection 1909.3. Additional support documents for the use of Microsynthetic Fibers would include ASTM C1116 and ACI 544.1R.

The use of the wire mesh is also addressed in this subsection. Unfortunately. there is very limited documentation regarding WWF as secondary reinforcement. There are no standard tests to provide limits of performance. All five of the equations used to establish the appropriate WWF to be utilized are empirical equations, which are based solely on observation not performance.

The specifications and the codes recognize the value of 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.

DEPENDABLE

For over 25 years, Fiber Reinforced Concrete (FRC) has delivered solid, dependable results in projects down the street and around the world. Initial acceptance was based more on faith than fact, but conclusive tests now quantify the clear benefits of this 3-dimensional concrete reinforcement system. With the increasing acceptance of FRC came the development of new fibers that contributed even more benefits and value to the concrete.

ABC Polymer Industries now has available a full spectrum of fibers for use in reinforcing concrete. Besides the monofilament and fibrillated polypropylene fibers in multiple forms we also produce macrosynthetic fibers and have available nylon and steel fibers. Also we can provide blends of these various products to meet current specification requirements.

Right now I believe the ready mix producers and the concrete contractors have an excellent opportunity to enhance their financial gains simply by taking the opportunity presented and promote Fiber Reinforced Concrete. The engineering community and the code writers finally have realized there is an advantage to using a 3-dimensional secondary/temperature-shrinkage reinforcement versus a single plane of wire mesh, which more often than not ends up residing on the subgrade.

As time goes by we see more interest in Fiber Reinforce Concrete (FRC) developing in the engineering community. There are a number of indicators including the increased number of specifications on major projects and the number of states' Departments of Transportation producing specifications specific to FRC.

Back in March of 2005 the three reining construction code bodies in the United States united into a single code body with a single set of standards and specifications. ICBO, BOCA and SBCCA united under the banner of ICC or International Code Council. Today there are two sets of standards and specifications; one referenced as International Building Code (IBC) and the second as the International Residential Code (IRC). The IBC provides standards for commercial construction and IRC covers single and multi-family residential construction. Almost all states and local agencies utilize the ICC codes, both IBC and IRC.

As the use of Macrosynthetic Fibers and Macrosynthetic Fiber-Microsynthetic Fiber Blends grows,  a more precise understanding of the properties of concrete reinforced with these materials is required. Currently there are three tests on the books at ASTM that are specific to the testing of fiber reinforced concrete (FRC) post-first crack. These tests methods are C1399, C1550 and C1609. Here in the United States C1399 and C1609 are the test methods of choice. C1399 was originally developed to test microsynthetic fibers but has become the secondary test for macrosynthetic fibers and macro-micro blends. C1609 is an updated test method of the ASTM C1018 test, which has been eliminated. The C1609 test method is the most versatile as it can be used with macros, steel and blends.

Q: How do we, as ready mix concrete sales people, flip a project specification from conventional temperature-shrinkage reinforcement to Fiber Reinforced Concrete (FRC) or from one FRC system to the system we are selling.

ABC Polymer Industries has assembled a number of papers authored by Bobby Zellers, Director, Engineering Services to help the Ready Mix Producer understand what exactly is a macrosynthetic fiber and how to evaluate the applicability of and benefits of macrosynthetic fibers using the specific requirements (specifications) of a given project. A number of these documents will help in educating engineers and contractors in the use of macrosynthetic fibers.

Let's Talk about defining industry terms and a little about FRC testing.

There are some terms being used when we are defining synthetic and/or steel fibers as well as their properties and applications that create some confusion for those that may be considering using Fiber Reinforced Concrete.

First and foremost when designing a Fiber Reinforced Concrete (FRC) mix make sure there is sufficient mortar (Cement and sand) to coat the extra surface area contributed by the fibers to the mix.

Plastic Shrinkage Crack Reinforcement would be appropriate for slabs-on-grade and on elevated deck and thin precast concrete elements where the weather conditions (temperature, wind speed and humidity) could produce plastic shrinkage cracks. The cause of plastic shrinkage cracking is rapid loss of moisture from the surface of the concrete element.

Item Microsynthetic Fibers Welded Wire Fabric

1.0 to 1.5 lbs/pcy

6x6 W1.4 x W1.4

6x6 W2.0 x W2.0

There is so much more gained when the engineer specifies synthetic fibers as the  temperature-shrinkage reinforcement instead of the wire mesh. The added value when using the 3-dimensional reinforcement system in lieu of the single plane of wire mesh is truly measurable.

Cement Industry to turn around this year

Following A 26.6 percent decline in cement consumption from 2008 to 2009, the Portland Cement Association (PCA) forecasts a modest 5.2 increase in this year-the first year-over-year improvement since consumption peaked in 2005. Stimulus-funded infrastructure projects and pent-up demand for sustainable, cost-effective materials will propel consumption up another 16.5 percent in 2011 and 14.5 Percent in 2012, according to PCA.

It is Spring and the time is ripe to ferret out those projects that are specified with conventional secondary/temperature-shrinkage reinforcement and flip them to current generation microsynthetic fiber reinforcement or new generation macrosynthetic fiber reinforcement.