The report has been prepared by the Joint Working Group on High Strength/High Performance Concrete, set up by CEB and FIP and comprising 15 experts from Europe, North America, Japan and Australia. Part one 'Recommended Extensions to Model Code 90' identifies the lacuna in existing regulations and proposes supplementary or alternative solutions to be applied with caution for concrete grades above C 50. In order to facilitate its use the report is edited in two columns following the numbering of the CEB-FIP Model Code 1990. It will be presented for approval to the 30th CEB Plenary Session in Berlin, September 1995. Part two identifies the research needs resulting from those clauses of Model Code 90 which needed amendments. Also more basic research needed for a better understanding of mechanical, physical and chemical processes which cannot be connected directly to a short-term application has been included."--Back cover.
The introduction by the Task Group's convenor L. Taerwe 'Model uncertainties in reliability formats for concrete structures' gives an outline of the general approach summing-up his former contribution to CEB Bulletin 219 'Safety and Performance Concepts' on the consistent treatment of model uncertainties in reliability formats for concrete structures. The second contribution 'An analysis of model uncertainties: ultimata limit state of buckling' by M. Pinglot, F. Duprat and M. Lorrain investigates the model uncertainties of hinged columns and the influence of boundary conditions and proposes appropriate safety elements. The third contribution 'Model uncertainties concerning design equations for the shear capacity of concrete members without shear reinforcement' by G. König and J. Fischer compares suggested formula from various sources (CEB-FIP Model Code, Eurocode 2,Remmel) to 176 test results from a data base covering concrete strengths from 20 to 111 MPa.
The first part of the report is devoted to linear elements (beams, columns) and includes chapters on shear and flexure in beams, ultimate limit state design of prestressed beams, and of reinforced concrete members under combination of bending with axial load and shear, of beams subjected to torsion, and a chapter on shear design based on truss models with crack friction. The second part treats two-dimensional elements and includes background information on ULS design of wall, shell, and slab elements. lt concludes with a chapter on axisymmetric punching of slabs.