Title: Steel Fiber Reinforced Concrete Overlays on Asphalt Pavement
Author(s): Shiro ibukiyama, Kaoru Seto, and Shuichi Kokubu
Publication: Symposium Paper
Appears on pages(s): 351-374
Keywords: concretes; bearing capacity; resurfacing; serviceability; expand ing agents;
fi bers; mix p Structural design fiber reinforced roportioning;
Experiments concerning the bearing capacities of thin steel fiber-reinforced concrete (SFRC) slabs which are most important in using SFRC for over-lays on asphalt pavements are reported and installation operations and serviceabilities of actual overlays are described. According to loading tests, SFRC slabs with crushed-rock and asphalt-concrete bases possess bearing capacities of about 17 to 22 tons and it is thought actual traffic loads can be amply supported. Consequently, it is considered the use of SFRC immune to rutting and distortion would Drovide excellent resurfacing, smooth and durable, and economical as well. It is further shown that the "Yield Line Theory" can be applied to design of resurfacing using SFRC. Actual overlays were constructed on asphalt pave-ments in the northern city of Sapporo where extreme de-formation occurs due to wear in winter and plastic flow in summer. The overlays were of fiber contents of 2 percent and 1.4 percent measuring 3x130x0.05 and 3x200x 0.05 meters, respectively, and were among the first SRFC overlays in Japan. Until the fall of 1981 they had been in service 4 years and 2 years (5 and 3 win-ters), respectively, and worn down 1 to 2 centimeters, with a fair amount of cracks traversing the overlays. However, most of the cracks are connected well by steel fibers, while the wear is of a degree not to impede traffic. Overall, it may be judged that serviceability under traffic is good and that economic losses due to repairs of asphalt pavements at least every 2 to 3 years can be alleviated to a considerable extent.