In order to standardize painting system applied on steel curbing, reflective sheet and reinforced plastic curbing, following kinds of curbing were installed at Kitakyushu port in April, 1972.
　Five kinds of painting system on steel curbings.
　Two kinds of reflective sheet on steel curbings and reinfroced plastic curbings.
　Three reinforced plastic curbings.
　indicate as follows:
(1) no limitation of the design load is required from the standpoint of crack width.
(2) the measured data make clear that compressive in-plane force is generated in the slab sections.
(3) the present design codes are inadequate to estimate the ultimate strength of fixed slabs.
　Then, the theoretical equation regarding the ultimate strength of flexure and punching shear is induced taking into consideration the membrane effect. The calculation results obtained according to that analysis are roughly in agreement with the testing results. Finally, the following practical equation for the shear strength of fixed slabs is recommended.