A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 2001

Hybrid ferrocement manhole covers are investigated with the aim of improving the structural performance of the covers subjected to vertical patched loads. Twenty-six hybrid ferrocement manhole covers of diameter 870 mm and thickness 70 mm containing steel fibers, namely, commercial and galvanized steel fibers, and varying steel fiber contents from 0-2% by volume were tested while skeletal steel and wire mesh were kept constant. The influence of different types of steel fibers and fiber contents of hybrid ferrocement manhole covers was examined. The results indicated that the use of commercial steel fibers was evidently more effective in improving the load carrying capacity and ductility of the covers than those of galvanized steel fibers. The results also indicated that the increase in the steel fiber contents improved the load carrying capacities and ductility of the manhole covers. The test results showed that the load canying capacities of hybrid ferrocement manhole covers were higher than that of conventional ferrocement manhole covers and that specified by the Chinese National Standard CNS 4993 for vehicular traffic. The performance compared favorably with commercially available cast iron manhole covers. Their costs are higher than ferrocement manhole covers but their performances are better. They are also to be cheaper than cast iron manhole covers currently used.