Abstract
This work presents a study on the behaviour of reinforced concrete waffle flat slabs with solid panels around internal columns and without moment transfer. Testes on 6 square waffle flat slab models were carried out, with 2400 mm in side length, 185 mm in height, 70 mm in top slab thickness, 115 mm in ribs height, 50 mm in ribs width, and 270 mm in ribs spacing, from center to center. The variables were the size of the solid panels (either 590 x 590 mm or 1130 x 1130 mm), ribs web steel ratio, type and layout. Except for one model that failed in flexure by crushing the ribs at the solid panel, all other models failed in shear by diagonal tension of the ribs. Test results were analyzed and compared with one another and with the estimations of existing expressions from codes and from other works available in the literature for punching shear of the solid panels around the column and ribs shear next to the solid panels. Finally, proposals for the design procedures for the slab region within the lines of zero moments and around the columns are given, regarding the definition of the solid panel size as a function of the ribs resistances towards shear and flexure.