Course detail

Prestressed Concrete

FAST-BL011Acad. year: 2018/2019

Principle of prestressing. Basic concept of pretensioning and post-tensioning. Material properties, manufacturing, types. Pretensioning operations, technology. Post-tensioning operations, technology, prestressing systems.
Losses of prestressing of pretensioned and post-tensioned concrete, tendon profiles.
Equivalent load method, statically determinate and indeterminate structures, examples. Response of structures subjected to prestressing, simplifications, decompression state.
Resistance of prestressed members against cracks. Tensile stresses in the concrete after cracking. Control of crack width and deflection of prestressed members. Ultimate limit state of prestressed members, full stress-strain response, shear resistance.

Department

Institute of Concrete and Masonry Structures (BZK)

Learning outcomes of the course unit

A student gains these knowledge and skills:
Understanding of the behaviour of prestressed concrete structures. Knowledge of calculation of effect of prestressing on structures. Knowledge of production technology of prestressed members. Analysing and designing prestressed concrete structural members. Designing prestressed concrete load-bearing systems including their realisation and structural solution.

Prerequisites

structural mechanics, theory of elasticity, plasticity, design concrete members and concrete structures

Co-requisites

do not required

Recommended optional programme components

Not applicable.

Recommended or required reading

Not applicable.

Planned learning activities and teaching methods

Teaching methods depend on the type of course unit as specified in the article 7 of BUT Rules for Studies and Examinations. Education runs in the forms of lectures and trainings. Character of the lectures is based on definition of basic principles, problems and methodology. In the trainings the main subject matters are trained on individually defined projects (examples).

Assesment methods and criteria linked to learning outcomes

To gain the credit, the students should elaborate individually defined design and calculate specified task. The students are obliged to consult the design continuously in the given terms and submit it to the fixed date. The presences in training lessons are checked. An exam consists both of the written part, in which the task is elaborated, and the theoretical part. To pass the exam successfully, both parts should be accomplished.

Language of instruction

Czech

Work placements

Not applicable.

Course curriculum

1. Basic concept of prestressing. Behaviour of non-prestressed and prestressed concrete beams. Material properties of concrete.
2. Prestressing tendons and bars. Prestressing technology, basic terminology. Pretensioned concrete.
3. Post-tensioning operations, technology, prestressing systems.
4.-5. Losses of prestressing of pretensioned and post-tensioned concrete. Construction and serviceability stages.
6. Effects of prestressing. Equivalent load method. Concordant tendon, transformation of tendon.
7. Design of prestressing - load balanced method. Allowable stresses. Crack resistance.
8. Structural analysis of step-by-step built structures, non-homogeneity of structures. Creep analysis.
9. Ultimate limit state of prestressed members loaded by axial force and bending moment, decompression state, initial state of stress.
10. Prestressed members loaded in shear and torsion, stress analysis, proportioning.
11. Anchorage zone analysis, calculation model, check of resistance, proportioning.
12. Serviceability limit states (SLS). Crack resistance, tensile stresses in the concrete after cracking.
13. Control of crack width of prestressed members. Control of deflection.

Aims

Understanding of the behaviour of prestressed concrete structures.
Design of prestressed concrete structural members and structural systems, analysis and detailing.

Specification of controlled education, way of implementation and compensation for absences

Extent and forms are specified by guarantor’s regulation updated for every academic year.

Classification of course in study plans

  • Programme B-P-C-SI (N) Bachelor's

    branch K , 4. year of study, winter semester, 5 credits, compulsory

  • Programme B-P-E-SI (N) Bachelor's

    branch K , 4. year of study, winter semester, 5 credits, compulsory

  • Programme B-K-C-SI (N) Bachelor's

    branch K , 4. year of study, winter semester, 5 credits, compulsory

Type of course unit

 

Lecture

26 hours, optionally

Teacher / Lecturer

Syllabus

1. Basic concept of prestressing. Behaviour of non-prestressed and prestressed concrete beams. Material properties of concrete.
2. Prestressing tendons and bars. Prestressing technology, basic terminology. Pretensioned concrete.
3. Post-tensioning operations, technology, prestressing systems.
4.-5. Losses of prestressing of pretensioned and post-tensioned concrete. Construction and serviceability stages.
6. Effects of prestressing. Equivalent load method. Concordant tendon, transformation of tendon.
7. Design of prestressing - load balanced method. Allowable stresses. Crack resistance.
8. Structural analysis of step-by-step built structures, non-homogeneity of structures. Creep analysis.
9. Ultimate limit state of prestressed members loaded by axial force and bending moment, decompression state, initial state of stress.
10. Prestressed members loaded in shear and torsion, stress analysis, proportioning.
11. Anchorage zone analysis, calculation model, check of resistance, proportioning.
12. Serviceability limit states (SLS). Crack resistance, tensile stresses in the concrete after cracking.
13. Control of crack width of prestressed members. Control of deflection.

seminars

26 hours, compulsory

Teacher / Lecturer

Syllabus

1. Post-tensioned bridge beam - design: Load, design of a cross section, material characteristics, types of anchors, structural principles, design of prestressing force and its eccentricity.
2. Verification of prestressing force design via loads effects compensation method, design of cables and their trajectory.
3. Effects of prestressing on the structures - examples.
4. Post-tensioned bridge beam - design (continuation): Effects of load, initial (anchoring) stress, immediate changes of prestressing.
5. Simplified calculation of time-dependent changes of prestressing. Time behaviour of prestressing force magnitude.
6. Correction.
7. Serviceability limit states – limit state of stress and cracks limitation (decompression).
8. Ultimate limit state – bending moment.
9. Ultimate limit state - shear, design of shearing reinforcement.
10. Verification of anchors, design of reinforcement in the anchoring area, drawing of active and passive reinforcement.
11. Serviceability limit states – deflection of a beam. Correction.
12. Effects of prestressing on the structures (continution): Effect of prestressing on the structures progressively erected - examples.
13. Design submission. Credit.