Theory and design of reinforced and prestressed concrete structures A ( 5 CFU )

Finalità

Aim of the course is to provide a specific knowledge for the design and the construction of reinforced and prestressed concrete structures. A state of the art of the most important theoretical and experimental outcomes is provided. Moreover, recent Italian and European codes (Eurocode1, Eurocode2, Eurocode8) are described.

Programma

ƒ{ Details of reinforcement: stairs, footings, corbels, shear walls, deep beams, beam-column joints, frame corners, strut and tie models, development and splices of reinforcement, mechanical anchorage.

ƒ{ Reliability: comparison between deterministic and probabilistic approaches, probabilistic methods of level 3, 2, 1, partial safety factors.

ƒ{ Loads: combination of actions, influence lines, loads on continuous beams and frames, load descent, influence areas.

ƒ{ Materials: ductile vs. brittle materials, fracture energy, cohesive crack model, ductile vs. brittle structures, size-effect.

ƒ{ Ultimate limit state of bending and axial force: behavior of beams in bending, stress-strain relationships of steel and concrete, possible strain distributions, M-N diagrams, design of beams and columns, axial load and biaxial bending, Mx-My-N diagrams.

ƒ{ Behavior of reinforced concrete members: behavior of reinforced concrete members in tension, bond between steel and concrete, tension-stiffening, crack width.

ƒ{ Serviceability limit state: behavior of reinforced concrete beams in bending, moment-curvature relationship, crack width, cracking moment, minimum reinforcement, serviceability limit state of deformation, checking rotations and deflections by calculation, serviceability limit state of stress.

ƒ{ Ultimate limit state of shear: shear behavior of beams, truss model, design of shear reinforcement, curtailment of longitudinal tension reinforcement.

ƒ{ Ultimate limit state of torsion: behavior of solid and thin walled cross sections, design procedure, shear-torsion interaction.

ƒ{ Prestressed structures: pre-tensioned, bonded post tensioned and unbonded post tensioned structures, external prestre ss, statically indeterminate prestressed structures, concordant tendon.

ƒ{ Loss of prestress: elastic shortening of concrete, friction loss, anchorage seating loss, shrinkage of concrete, creep of concrete, relaxation of tendon stress.

ƒ{ Creep and shrinkage: behavior of concrete in time, superposition of the effects in time, AAEM method, stress distribution in columns, prestressed beams and composite beams, behavior of statically indeterminate structures.

ƒ{ Second order effects: second order effects and material non-linearity in a column cast at the base, differential equations, methods based on estimation of curvature, finite differences methods, second order effect in reinforced concrete frames, P-Delta method and general finite element method.

ƒ{ Structural analysis: linear elastic analysis, linear analysis with limited redistribution, plastic analysis, non-linear analysis.

ƒ{ Reliability: comparison between deterministic and probabilistic approaches, probabilistic methods of level 3, 2, 1, partial safety factors.

ƒ{ Loads: combination of actions, influence lines, loads on continuous beams and frames, load descent, influence areas.

ƒ{ Materials: ductile vs. brittle materials, fracture energy, cohesive crack model, ductile vs. brittle structures, size-effect.

ƒ{ Ultimate limit state of bending and axial force: behavior of beams in bending, stress-strain relationships of steel and concrete, possible strain distributions, M-N diagrams, design of beams and columns, axial load and biaxial bending, Mx-My-N diagrams.

ƒ{ Behavior of reinforced concrete members: behavior of reinforced concrete members in tension, bond between steel and concrete, tension-stiffening, crack width.

ƒ{ Serviceability limit state: behavior of reinforced concrete beams in bending, moment-curvature relationship, crack width, cracking moment, minimum reinforcement, serviceability limit state of deformation, checking rotations and deflections by calculation, serviceability limit state of stress.

ƒ{ Ultimate limit state of shear: shear behavior of beams, truss model, design of shear reinforcement, curtailment of longitudinal tension reinforcement.

ƒ{ Ultimate limit state of torsion: behavior of solid and thin walled cross sections, design procedure, shear-torsion interaction.

ƒ{ Prestressed structures: pre-tensioned, bonded post tensioned and unbonded post tensioned structures, external prestre ss, statically indeterminate prestressed structures, concordant tendon.

ƒ{ Loss of prestress: elastic shortening of concrete, friction loss, anchorage seating loss, shrinkage of concrete, creep of concrete, relaxation of tendon stress.

ƒ{ Creep and shrinkage: behavior of concrete in time, superposition of the effects in time, AAEM method, stress distribution in columns, prestressed beams and composite beams, behavior of statically indeterminate structures.

ƒ{ Second order effects: second order effects and material non-linearity in a column cast at the base, differential equations, methods based on estimation of curvature, finite differences methods, second order effect in reinforced concrete frames, P-Delta method and general finite element method.

ƒ{ Structural analysis: linear elastic analysis, linear analysis with limited redistribution, plastic analysis, non-linear analysis.

Attività d'esercitazione

Exercises on the main topics of the course are solved

Modalità d'esame

The exam is divided in two parts: the first written part consists of a numerical exercise and a theoretical question. In the second oral part design problems and details are treated.

Propedeuticità

¡§Scienza delle Costruzioni¡¨ (Mechanics of Materials) and ¡§Tecnica delle Costruzioni¡¨ (Structural Mechanics)

Testi consigliati

D. Ferretti , I. Iori, M. Morini " La stabilita`delle strutture: il caso delle costruzioni in cemento armato", McGraw-Hill Italia, 2002.

R. Walther , M. Miehlbradt Progettare in calcestruzzo armato , Milano, Hoepli.

A. Migliacci, F. Mola, Progetto agli stati limite delle strutture in cemento armato , Milano, Masson, 1996.

R. Walther , M. Miehlbradt Progettare in calcestruzzo armato , Milano, Hoepli.

A. Migliacci, F. Mola, Progetto agli stati limite delle strutture in cemento armato , Milano, Masson, 1996.