Technological advances in fiber reinforced concrete (FRC) offer possible solutions to these problems [1 to 4]. Some advantages of FRC appear to be: pavements may be constructed with thinner cross-sections and have performance characteristics and constructability comparable to the thicker non-fiber reinforced concrete; FRC may reduce spalling even in concrete with quartzite aggregate which has a higher thermal coefficient than other aggregate types; joint spacing may be increased due to FRCs enhanced properties, therefore reducing maintenance; 3Ms polyolefin fibers have advantages over steel fibers in that they are chemically resistant and have a lower corrosive potential [5 to 24].
SDDOTs research project, SD94-04 Evaluation of Non-Metallic Fiber Reinforced Concrete in PCC Pavements and Structures, constructed 4 different test sections using 3Ms Polyolefin Fiber System. The test sections were: 1) full depth pavement, 2) bridge deck overlay, 3) Jersey Barrier, and 4) whitetopping. Also the other SDDOT project, Demonstration of Polyolefin Fiber Reinforced Concrete in a Bridge Deck Replacement, 1995-96, used 3Ms Polyolefin fibers. The test section included, the replacement of the deck slab and both barriers for a bridge across Interstate 90 at Exit 10. Minimal or no additional effort was needed during the construction of these test sections due to the addition of the fibers. The preliminary field inspections show that the non-metallic fiber reinforced concrete (NMFRC) is performing well in each application [5,24]. The improved properties make polyolefin fiber reinforced concrete an attractive material for concrete pavements. Before NMFRCs use in full depth pavements could be accepted, the following items needed to be addressed: the constructability and economic impacts of using these fibers needed to be determined in order to support its continued use; design criteria needed to be established to determine pavement thickness, joint spacing, etc.; the effectiveness of load transfer across joints and random cracks needed to be determined; and the behavior of jointed and unjointed slabs needed to be addressed.
There was an urgent need for the proposed research in order to find answers for the above stated problems. Due to the favorable performance of the relatively small NMFRC test sections, constructed as part of SD94-04, construction of larger full depth pavement test sections in SD96-15 which exhibit full-scale behavior using a fiber addition rate of 15 kg/m3 (25 lbs/yd3) answered many of the questions.