Prestressed Structures

Code:

M.EC024

Acronym:

EPE

Keywords
Classification	Keyword
OFICIAL	Structures

Instance: 2023/2024 - 1S

Active?	Yes
Responsible unit:	Department of Civil and Georesources Engineering
Course/CS Responsible:	Master in Civil Engineering

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
M.EC	27	Syllabus	2	-	6	45,5

Teaching language

English
Obs.: Nas aulas com estudantes não proficientes na língua portuguesa, a língua de trabalho é inglês. Caso contrário, poderá ser usada a língua portuguesa.

Objectives

To describe the main concepts related to the analysis and design of structures which behaviour is not adequately described by the Bernoulli principles. To relate models that describe the uniaxial behaviour of concrete elements subjected to tension or compression with specific design methodologies. To identify different techniques for applying to prestress on concrete structures and the respective methods of analysis and design. Calculate and develop solutions based on learned structural methods, applying the European structural codes. To draw structural solutions that illustrate the obtained design. Acquisition of a set of skills to elaborate a project of prestressed structures, including prefabricated members, considering the respective construction phases, laminar concrete structures and specific issues related to prestressed slabs, namely, flat slabs.

Learning outcomes and competences

SKILLS AND LEARNING OUTCOMES:

Knowledge: Describe main concepts related to the analysis and design of structures which behaviour is far from linear relationships. To relate models that describe the uniaxial behavior of concrete elements subjected to tension or compression with specific design methodologies. To identify different techniques for applying prestress on concrete structures and the respective methods of analysis and design.

Comprehension: To select different models for the design of structural elements for different loading and geometry conditions. To apply appropriate methods for the design of laminar structures, discontinuous regions and prestressed structures.

Application: Calculate and develop solutions based on learned structural methods, relying on European structural codes. To draw structural solutions that illustrate the obtained design.

Analysis: Discuss and compare different structural solutions and hierarchical them in order to analyze the most appropriate. Discuss the structural code proposals based on the knowledge acquired in the interpretation of models that describe the structural behaviour.

Synthesis: To recommend and formulate alternatives to proposals that are currently used, in order to formulate realistic solutions.

Evaluation: Recommend new proposals to overcome shortcomings in the adopted procedures. Consider alternative solutions to be used in the future.

Civil Engineering Project: Acquisition of a set of skills to elaborate a structural project, which are related to the analysis and design of laminar concrete structures subjected to high local forces, prestressed structures and the respective construction phases and specific issues related to slabs, namely, waffle slabs.

Research in Civil Engineering: The application of models and methodologies with innovative nature in comparison to the classical methods, combined with aspects of more complexity, is open for discussion, and new proposals may be possible, even for the existing codes. Therefore, the search for new alternatives leads to fields of research of great interest for the analysis and design of structures.

Civil Engineering Practice: The learning outcome for the preparation and the organization of the structural project process related to the design of laminar and prestressed structures is essential to monitor civil engineering works.

Working method

Presencial

Pre-requirements (prior knowledge) and co-requirements (common knowledge)

This course deepens and applies to civil engineering works subjects related to structural concrete, with special emphasis on the areas covered by Strength of Materials, Structural Analysis, Structural Concrete, Structural Engineering and Design of Concrete Structures.

Program

Chapter 1 - Prestressed concrete structures (45% of total time)
Mechanical properties of concrete. Time dependent effects. Prestress technology. Equivalent loads. Design of cross sections. Design of isostatic beams. Evaluation of prestress losses. Hyperstatic structures. Stress redistribution and internal forces in evolving prefabricated prestressed beams.

Chapter 2 - Models for the analysis of behaviour and design of concrete structures (25% of total time)
Models for the analysis of behaviour of structural members under tension and compression. Localized compression. Anchorage zones of prestress. Walls, slabs and shells. Laboratory experimental tests.

Chapter 3 - Design of regions with discontinuities (15% of total time)
Strut and tie models: analysis and geometry. Design and verification of the model nodes. Corbels. Deep beams.

Chapter 4 - Analysis and design of slabs (15% of total time)
Types of slabs and behaviour performance. Methods for evaluating the internal forces. Flexural design. Punching. Slabs prestressed with unbounded tendons. Constructive provisions and detailing.

PERCENTUAL DISTRIBUTION: Scientific component – 70% Technological component – 30%

DEMONSTRATION OF THE SYLLABUS COHERENCE WITH THE CURRICULAR UNIT'S OBJECTIVES:
The learning outcomes within the specialization of Structures and Geotechnics is focused on the structural conception, methods for structural analyses and their application to civil engineering problems, from current to special ones, and on the techniques related to their construction, relying on European structural codes, computational programs and visits to civil engineering works. This course, Prestressed Structures, completes the training in the analysis and design of structural concrete and will focus on the study of types of structures not covered previously with necessary in-depth, namely, laminar concrete structures (walls and slabs) and prestressed concrete structures.

Mandatory literature

Féderation Internationale du Béton; Structural concrete. ISBN: 2-88392-041-X (vol. 1)
Collins, Michael P.; Prestressed concrete structures. ISBN: 0-13-691635-X
CEN - Comité Europeu de Normalização; Norma Europeia - Eurocódigo 2: Projecto de estruturas de betão, Abril 2004
fib - Fédération internationale du béton / International Federation for Structural Concrete; fib Model Code for Concrete Structures 2010, Ernst & Sohn, 2013. ISBN: 978-3-433-03061-5
Hurst, M. K.; Prestressed Concrete Design, Taylor & Francis LTD, 2005. ISBN: 9780419218005
Joaquim A. Figueiras; Compilação de textos e notas de apoio às aulas

Complementary Bibliography

Appleton Júlio António da Silva; Estruturas de betão. ISBN: 978-972-8620-21-9
Leonhardt, Fritz; Construções de concreto
Comité Euro-International du Béton; CEB-FIP model code 1990. ISBN: 0-7277-1696-4

Teaching methods and learning activities

All the subjects of the course are presented during theoretical classes, where the theories and models are introduced, together with the resolution of some representative practical exercises. The practical exercises to be solved by the students are discussed during practical classes. Laboratory work, visits to conferences and construction works complete the learning outcomes.

DEMONSTRATION OF THE COHERENCE BETWEEN THE TEACHING METHODOLOGIES AND THE LEARNING OUTCOMES:
Calculate and develop solutions based on learned structural methods, applying the European structural codes. To draw structural solutions that illustrate the obtained design. Discuss and compare different structural solutions and hierarchical them in order to analyze the most appropriate. Discuss the structural code proposals based on the knowledge acquired in the interpretation of models that describe the structural behaviour. To recommend and formulate alternatives to proposals that are currently used, in order to formulate realistic solutions. Recommend new proposals to overcome shortcomings in the adopted procedures. Consider alternative solutions to be used in the future. Acquisition of a set of skills to elaborate a structural project, which are related to the analysis and design of laminar concrete structures subjected to high local forces, prestressed structures, prefabricated members and the respective construction phases and specific issues related to slabs, namely, flat slabs.

Software

Autodesk Robot Structure Analysis

keywords

Technological sciences > Engineering > Civil engineering
Technological sciences > Engineering > Civil engineering > Concrete engineering
Technological sciences > Engineering > Civil engineering > Structural engineering

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Exame	70,00
Trabalho escrito	30,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Elaboração de relatório/dissertação/tese	8,50
Estudo autónomo	78,00
Frequência das aulas	45,50
Trabalho escrito	20,00
Trabalho laboratorial	10,00
Total:	162,00

Eligibility for exams

Achieving final classification requires compliance with attendance at the course unit, according to the M.EC assessment rules. It is considered that students meet the attendance requirements if, having been regularly enrolled, the number of absences of 25% for each of the classes’ types is not exceeded.

Calculation formula of final grade

The final grade is based on a distributed evaluation and a final exam.

The distributed evaluation has an optional character, consisting on the evaluation of practical problems related to the design of prestressed concrete structures and the report of the experimental work.

All evaluation components are expressed on a scale of 0 to 20.

The final grade is calculated by the following formula:

CF = max {CT ; EF} where, CT = PA / 2 x (TP + TE) + PF x EF

PR - grade of a practical problems from worksheets;
TE - grade of the report of experimental work;
EF - grade of the final exam.

The weights associated with the indicated grades are as follows: PA = 30% PF = 70%

NOTE 1: The evaluation tests associated with the distributed component are optional. If the student does not perform any of these tests, the respective weights are added to PF.

NOTE 2: All students that are registered in the course are classified according to this method.

NOTE 3: Students who have attended the course in the previous academic year may maintain the grades of the distributed component evaluation, maintaining, in this case, the weights specified in that academic year.

Examinations or Special Assignments

Practical work consists of problems related to the design of prestressed concrete structures and a report of the experimental work to be carried out during the semester.

Special assessment (TE, DA, ...)

Due to the optional condition for the distributed evaluation, students with special status are subjected to the same conditions of the final evaluation of the other students.

Classification improvement

The classification improvement can be performed under the same conditions of the final exam and the accumulation of the classification of distributed evaluation.