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, 2000

In the construction of industrial floor or massive concrete, the works of fixing rebars and casting concrete take a lot of time consumption reflecting to high cost of construction. Steel fiber reinforced concrete slab on grade was used to solve those problems, but it still can not be used in the areas having soft soil conditions. Steel fiber reinforced concrete flat slab on piles is the new alternative to eliminate all those drawbacks as mention before. Therefore this investigation was done to examine the flexural behavior and applicability of steel fiber reinforced concrete flat slab on piles. The mathematical model and constitute compressive and tensile relationship had to be proposed to predict the flexural capacity of it. This proposed model also take account of the toughness and ductility advantages contributed from steel fiber. The accuracy of model had been examined by comparing with published model from other researchers. The experimental investigation on various test series was carried out. The specimens of compressive, tensile, flexural, and full-scale slab test sizing 2.50 x 2.50 x 0.15 m ( W x L x T) on four hinge supports were tested by varying the volume fraction steel fiber from 0.25%, 0.50%, 0.75%, and 1.00%. The test results showed that the slab and specimens with 0.25% Vf is the optimum mix design that give maximum strength and moment capacity to slab. Higher amount of steel fiber does not give higher strength, this resulted from the hard of compaction and reducing of cement content in concrete mix which obstructed steel fibers develop their full interfacial strength. These cause low tensile, compressive, and flexural strength. The proposed model for flexural strength gives a good agreement with the others model proposed by the previous researchers. In addition, the result from this proposed model for flexural strength of full-scale test of slab shows the good accuracy with test result. From the analytical result from Ansys 5.40 finite element software, the effective width of slab for computing moment capacity is 341 mm. Finally, the equivalent uniform applied load is calculated, it was found that the equivalent uniform applied load is 8.53 tons per m2, for first crack load.