Abstract:
his research deals with the grillage analysisof precast concrete slabs of various cross sectionswith concrete topping as the load distributor underpoint load applying at the middle of the precast slab.The deflection ,bending moment ,and the load distributionat the middle of the precast slabs are considered.The precast slabs , simply supported on two opposite sidesand free on the other two sides ,are made of the precastsections of various shapes ,namely, T ,plank ,up-side-down U ,and hollow core. The precast slabsare analyzed by varying the thickness of the concretetopping at 40,60and80 mm , the span length at 3 ,5and 7 m ,and the number of precast unit at 5 ,9 and 13unit. The results of the research are as follows :1. The grillage analysis shows that The deflection,bending moment , and the load distribution at the middleof the precast slabs are in good agreement with the testresults.The difference in load distribution only about 5 %2. The percentage of load distribution atthe middle of the precast slabs decreases as increasingthe thickness and compressive strength of concretetopping ,the span length ,and the number of precastunits. The decrease is not in linear proportion.3. The results of the grillage analysis can beconservatively used as the design data for the precastslabs under the point load , since the bending moment areare higher than the test results .