IDENTIFICATION AND INTERPRETATION OF THE SLAB EFFECT IN HIGH-STRENGTHCONCRETE

Square non-reinforced high strength concrete (HSC) slabs simply suppor ted have been subjected to biaxial loading to determine the resistance to microcracking, mesocracking and macrocracking and the increase in bending moment (a structural effect well known in the ease of ordinary concrete slabs). A comparison of the cracking characteristics of slab s and beams made of the same HSC and having the same thickness led us to conclude that this structural effect exists for HSC slabs as well. Its intensity, 1.3-1.4, compared with the values for ordinary concrete slabs, is not influenced by the better compressive strength of the co ncrete.