Study On Shear Capacity Of Cast-in-situ Reinforced Concrete Hollow Slab Floor System

Cast-in-situ reinforced concrete hollow slab floor system is a new floor structural system which can suit multilayer or tall buildings with big column gridding or big spaces. It can offer owners flexible spaces economically, and have a wide used foreground. Whereas, as a new technics, it's properties have not been comprehended adequately. And, it's calculating theoretics and design measures are still not consummate.Based on the contrast experiments and analysis of two groups of parallel slabs and perpendicular slabs, further study on the differences of flexural rigidity of parallel slabs and perpendicular slabs; contrast the differences of shearing performance of parallel slabs and perpendicular slabs and the influence to shear compacity by web reinforcements and lateral ribs . Finally, some conclusions have been made.(1) When tube's diameter is small and endlong ribs and concrete up and down the tube is comparatively thicker, the dissimilarity of parallel slabs's flexural rigidity and perpendicular slabs's flexural rigidity is not evidence. When tube's diameter is big and endlong ribs and concrete up and down the tube is comparatively thiner, the dissimilarity of parallel slabs's flexural rigidity and perpendicular slabs's flexural rigidity is become evidence. And flexural rigidity increases when lateral ribs lacated in perpendicular slabs.(2) The shearing performance of parallel slab is good and it is like I-shaped beam;but the shearing performance of perpendicular slab is bad ,because its web plate is not continuous and longitudinal rib is weakness.(3) The shear capacity of perpendicular slabs increases a little when web reinforcements lacated in longitudinal ribs,so the effection of web reinforcements will be ignored.(4) The shear capacity of perpendicular slabs increases very much when lateral ribs lacated in, and longitudinal ribs will not be weakness.(5) The testing value of shear capacity is bigger than calculation for parallel slabs and perpendicular slabs, when the calculation is calculated by the formula of shear capcity in 《Technical specification for cast-in-situ concrete hollow floor structure》.(6) I will give some suggestion for formula of shear capacity, especially for perpendicular slabs when lateral ribs lacated in.