Dr. Ramakrishnan did a very good job working with designers, inspectors, and contractors during the design and constructing of the Non-Metallic Fiber Reinforced Concrete (NMFRC) bridge and barriers. He was able to complete several trial NMFRC mixes in the short time from the research projects conception to construction (approximately 2 months). In that same period, he responded to SDDOTs request by conducting additional trial mixes which took into consideration the volume of the fibers in the mix. During the construction of the test sections, Dr. Ramakrishnan collected and evaluated a significant amount of data. After construction, several detailed visual inspections were completed for the NMFRC deck and barriers with fewer and less detailed inspections completed for the sister bridge at Exit 10. In 1994, the sister bridges deck was overlaid with low slump dense concrete and the barriers were reconstructed with plain concrete. The report indicates that the NMFRC deck has significantly fewer visible cracks and reduced the amount of unsightly efflorescence on the bottom of the deck as compared to that seen on the sister bridge. It should be noted that the age difference of the decks is not considered in the report and that it would be difficult to do so. As for the NMFRC barriers, the visible cracks had widths less than ACI Committee 224s recommended tolerable crack width for deicing chemicals. However, aside from minimizing the unsightly efflorescence on the bottom of bridge decks and reducing the crack widths in the deck and barriers, the benefits resulting from NMFRC are not fully understood since SDDOT utilizes epoxy coated steel in the newly constructed decks and barriers to minimize corrosion.
The panel believes the study produced good results and feels that the use of NMFRC in some applications can assist the Departments in its effort to improve South Dakotas highway network.