Effectiveness of project-based learning in a reinforced concrete course of civil engineering

EFFECTIVENESS OF PROJECT-BASED LEARNING IN A REINFORCED CONCRETE COURSE OF CIVIL ENGINEERING

Eva Oller* , Marta Peña , Noelia Olmedo-Torre

Universitat Politècnica de Catalunya (Spain)

Received January 2023

Accepted October 2023

Abstract

The application of Project-Based Learning (PBL) in a Reinforced Concrete course through the development of a real-life civil engineering project from its conception, as a coursework, is a challenged experience for students. As long as the coursework evolves, students develop real ways to think as an engineer and they work in an environment similar to that of daily engineering practice.

The effect of the PBL implementation on learning and acquisition of knowledge and skills in a Reinforced Concrete subject from the [University] in [Country] has been analyzed through some evidences such as the partial and final grades, the results of a survey and the perceptions drawn from students’ interviews. As observed, thanks to the application of the PBL strategy, learning and motivation of students has increased, in addition to the final summative assessment, without a significant increase on the workload. This methodology improves not only the acquisition of knowledge and engineering skills, but also transversal skills such as entrepreneurship, leadership, communication, time management, teamwork and other social abilities directly related to those required by the current market for their future professional life.

 

Keywords – PBL, Real engineering projects, Reinforced concrete structures, Professional skills.

To cite this article:

Oller, E., Peña, M., & Olmedo-Torre, N. (2024). Effectiveness of project-based learning in a reinforced concrete course of civil engineering. Journal of Technology and Science Education, 14(2), 324-348. https://doi.org/10.3926/jotse.2067

 

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    1. 1. Introduction

1.1. Theoretical Framework

The change in the educational model of European universities aimed at promoting a qualitative leap in teaching-learning methodologies began with the Bologna treaty. These changes derived from different agreements reached in the European Union (EU) ended with the construction of the European Higher Education Area (EHEA). As a consequence of this process, in 2009 the Louvain-la-Neuve ministerial conference addressed the issue of student-centered learning.

The European educational context is immersed in a process of adaptation in the teaching of knowledge (Gómez-Soberón,Gómez-Soberón & Gómez-Soberón, 2009); from traditional lectures with the teacher as the only source of knowledge, to a more complete form focused on the student’s know-how and accompanied by the use of Information and Communication Technology (ICT). Many universities still retain traditional methods where master lectures prevail as the main form of instruction in higher education for many teachers (Stains, Harshman, Barker, Chasteen, Cole, DeChenne-Peters et al., 2018). Recent research has identified the necessary steps towards a change in teaching-learning methodologies. These changes include improvements in long-term applicable teaching practice and a model in which the student is the center of learning. It is necessary to change the academic culture with the incorporation of active learning methodologies in the instructional practices and that this change be lasting over time and used by a wide segment of university teachers.

The convergence towards the EHEA implies a series of changes in knowledge, the ways of understanding and carrying out university training (Pastor, 2011). The planning for subjects in the new EHEA using the European Credit Transfer System (ECTS) (ABET Engineering Accreditation Commission, 2019) should consider and include some changes that can be summarized in:

  • •Devoting more time and effort to continuous and formative assessment than to final and summative assessment. 

  • •Conducting assessments to improve, rather than simply monitor, learning and teaching-learning processes. 

  • •Assessing the different types of learning and competence planned, rather than just those assessable through traditional exams. 

  • •Valuing the learning process and its development. 

The benefits of these changes in the classroom are well documented, both in terms of overall student learning (Freeman, Eddy, McDonough, Smith, Okoroafor, Jordt et al., 2014), and in terms of narrowing gaps in course grades (Beichner, Saul, Abbott, Morse, Deardroff, Allain et al., 2007; Eddy & Hogan, 2014; Haak, HilleRisLambers, Pitre & Freeman, 2011). In addition, university training should accomplish the seven quality principles of Chikering and Gamson (Chickering & Gamson, 1991): 1) to encourage contact between students and Faculty; 2) to develop reciprocity and cooperation among students; 3) to encourage active learning; 4) to give prompt feedback; 5) to emphasize time on task; 6) to communicate high expectations to students; 7) to respect diverse talents and ways of learning.

1.2. Project-Based Learning (PBL)

Among the most validated teaching methodologies, the Project-Based Learning (PBL) is an active learning methodology focused on the participation and involvement of the student in the construction of their own knowledge. It is an interdisciplinary method with an innovative approach with origins in constructivist theories (Olmedo, Farrerons & Pujol, 2021) focused on work, learning, research and reflection. The resolution of the project will involve the development and acquisition of certain competencies, skills that can subsequently be transferred to the professional environment, since one of the main objectives of this method is for the student to learn to solve a professional problem (Granado‑Alcón, Gómez-Baya, Herrera-Gutiérrez, Vélez-Toral, Alonso-Martín & Martínez-Frutos, 2020). The importance of developing generic skills such as teamwork, oral and written communication, problem solving and self-directed learning (Passow, 2012; Warnock & Mohammadi-Aragh, 2016) allows students to be brought closer to the real world. According to numerous studies around the world, PBL is the most appropriate method to achieve an effective competency-based education that integrates knowledge, skills and values (Chinowsky, Brown, Szajnman & Realph, 2006; Gijselaers, 1996; Johnson, 1999; Kelly, 2007; Mulcahy, 2000; Padmanabhan & Katti, 2002; Parsons, Caylor & Simmons, 2005).

Its use in engineering courses has shown notable advantages to motivate and involve students in authentic real work situations, favoring problem solving, and developing critical thinking and professional skills (Akinci-Ceylan, Cetin, Ahn, Surovek & Cetin, 2022; Jonassen, 1997; Othman, Mat-Daud, Ewon, Mohd‑Salleh, Omar, Abd-Baser et al., 2017), improving conceptual understanding and perceptions of learning (Yadav, Subedi, Lundeberg & Bunting, 2011) and academic performance (Dağyar & Demirel, 2015; Gijbels, Dochy, Van Den Bossche & Segers, 2005; Leary, Walker, Shelton & Fitt, 2013). Existing studies have emphasized the importance of integrating real-world problems into engineering classes so that students are more comfortable with complex problems when they begin their professional career (Jonassen, 1997). Students gain career motivation, students’ employability improves because academia communicates to them knowledge and skills of the workforce, helping to bridge the gap between industry expectations and academic preparation (Bae, Polmear & Simmons, 2022).

PBL is a collaborative, learner-centered pedagogical approach in which students work in groups to build their knowledge and master course content. In this methodology learning occurs as a result of the effort students put into developing a project; in engineering studies they are always focused on tasks that can be performed by an engineer in professional practice. It is well known that students are more motivated and persistent in their efforts when they work in groups to carry out a project that they perceive as related to their future professional activity (Finelli, Klinger & Budny, 2001); they explore real-world problems and find answers through the completion of the project. Students also have some control over the project they will be working on, how the project will finish, as well as the final product.

In engineering education, one of the responses to the social demand for new skills has been to incorporate project-based learning (Du & De Graaff, 2009). PBL has the potential to assist students to acquire the necessary knowledge and skills required in industry today. PBL is, in various aspects, a very superior educational methodology compared to other traditional ones in engineering studies (Martinez, 2011) leading to an enhanced learning experience (Cappelleri & Vitoroulis, 2013) as it makes the delivery of both technical content and generic professional skills in a specialized course possible (Hesamzadeh, 2012).

PBL begins with the assignment of tasks that will lead to the creation of a final product. In this context, what really matters, is the learning that takes place in the process and not so much the final result. This is precisely one of the important differences between PBL and the traditional engineering final project, which puts the emphasis on the professional quality of the project outcome. Students work on open‑ended assignments, that could be more than one problem. They have to analyze the problems and generate solutions; design and develop a prototype of the solution and finally refine the solution based on feedback from experts, instructors, and/or peers.

The implementation of PBL requires teamwork and therefore a higher dedication with deliverables, planning, division of responsibilities, among others. First, it is necessary to train the student in the rules of teamwork. Second, a monitoring system must be organized that guarantees work distributed over time and where all students work. Finally, it is necessary to give the necessary importance to the project grade (López & Julià, 2014).

1.3. PBL in Civil Engineering

Aalborg University (Denmark) was founded in 1974 with Project-organized Problem-Based learning in all faculties, in particular in Civil Engineering, where 50% of the curriculum is based on PBL (University of Aalborg, 1974). PBL is then the center of the curriculum; and the remaining activities are defined to help PBL. The Faculty of Civil and Environmental Engineering at the Norwegian University of Science and Technology (NTNU) at Trondheim started to introduce a PBL string in 1997, combining it with traditional curriculum. After these two first experiences, other studies related to PBL in Civil Engineering support the application of PBL in undergraduate degree programs (Gavin, 2011). Quinn and Albano (Quinn & Albano, 2008) summarized different experiences in the use of PBL in Hydraulics (Johnson, 1999), Sustainable Development (Steinemann, 2003), professional practice issues (De Camargo-Ribeiro & Mizukami, 2005), and Construction (Chinowsky et al., 2006), and developed their experience in Structural Engineering. The University College of Dublin (Gavin, 2011) develops a PBL module of case studies in Civil Engineering which is taken by the Master students to apply the theoretical principles of Structural Engineering and Soil Mechanics into practical cases.

In Spain, the Civil Engineering School of Universidad de Castilla La Mancha (UCLM) (Coronado, 2003; Escuela de Caminos de Ciudad Real, n.d.) has implemented PBL in the Bachelor in Civil Engineering, in 25% of the ECTS of 2nd year, and in 32% of the credits of 3rd and 4th year. What UCLM graduates value most is teamwork, the ability to communicate, the ability to defend ideas, team leadership, and collaborative work. In addition, according to the opinion of the graduates, the PBL does not involve loss of knowledge, and can be learned actively and applied, acquiring knowledge and practical skills and abilities.

Another example of PBL implementation is that of the University of Santiago de Compostela for civil engineers training (Castro, Nunez, Iglesias & Valcarce, 2012), where students of 2nd year work on a real civil engineering project of a transport infrastructure, which serves as a basis for developing a much more global project involving other subjects related to Geotechnical Engineering, Hydraulics and Structures. Students have the opportunity to continue their work in other subjects of the 3rd and 4th year. As stated in (Castro et al., 2012), students acquired a more global view of the specific work carried out in the different subjects, and improved the coordination between the areas of knowledge involved in the project.

1.4. Context of the Study

The curriculum of the Bachelor in Civil Engineering at the [School] of the [University] includes the Reinforced Concrete subject, which is compulsory of 3rd year (6 ECTS). In year 2019/20, there was a change in the curriculum of the Civil Engineering degree. The contents of the subject remain be the same, but the group of year 2021/22, where PBL was applied, was made up only of students adapted from the old curriculum. Its main aim is that students acquire a basic understanding of the behavior of reinforced concrete structures and develop the capacity to conceive, design, build and maintain this type of structures. For this purpose, reinforced concrete structures design and assessment procedures are dealt with, following the existing regulations (Comisión Permanente del Hormigón. Ministerio de Fomento. Gobierno de España, 2008; European Committee for Standardization, 1992).

This subject is taught with an intensity of 4 hours per week (2 sessions of 2 hours during 15 weeks) and has around 30 students per year, in one group with the same professor during the whole term. The student has previous basic knowledge of strength of materials and construction materials. The current discipline establishes a connection between these two fields of knowledge incorporating technological aspects related to construction, along with criteria related to design of reinforced concrete structures (design, assessment and arrangement of the internal reinforcement). The RC course has a basic technological character, since it is the first contact of the student with concrete structures. Being the only compulsory subject of this topic in the bachelor, it gives a global overview to achieve a sufficient basis to address the most common problems in the design and construction of reinforced concrete structures.

At the end of the course, the student must be able to understand the advantages of reinforced concrete as a material and recognize its field of application; to understand the construction phases and the behavior of structures executed with this material; to design and assess RC elements using the limit state methodology by accomplishing the conditions of safety and serviceability; and to provide appropriate measures to ensure the durability of structures.

1.5. Previous Situation to the Application of PBL

The RC subject has been largely taught in a classical way through master theoretical and problem lectures to reinforce the theoretical concepts. As the student was unaware of the topic until the class started, little interaction was observed between the lecturer and the students during the class, and the students’ attitude was very passive. Although facilities were provided for students to ask questions in class and participate, few took profit. Short problems related to the verification of each limit state were solved during the course, but with a discrete global vision of a project from its initial conception. On the other hand, students carried out the corresponding assessments (two partial exams) and a group coursework. This coursework usually consists of the analysis of a structure, such if it was the sum of several short problems. Given a reinforced structure with a defined geometry, loads and materials, students obtained the envelopes of forces, and based on them, students calculated the passive reinforcement verifying the ultimate and serviceability limit states. Despite students completed the analysis of a structure, they did not conceive the project from the beginning.

In many cases, students arrived at the 3rd year with a lack of motivation and a rather passive attitude, thinking more about passing the exam than learning.

In the last years, it has been observed that students usually studied the subject in parts, depending on the partial exams, losing the global vision of the problem they will have to face during their professional life. At the beginning of the course, students took the subject daily or weekly. However, when they started having more homework assignments from other subjects, students came to class to listen but some of them did not follow the subject properly.

Students were more focused on the calculation itself, applying formulas to solve practical problems. In addition, it was difficult for them to have a critical spirit, and to analyze whether the results obtained from the problems were correct or not, and whether the order of magnitude was appropriate. The main reason is because this was the first time they faced an ill-structured problem that has not a single solution. In structural engineering, the same problem statement can have multiple correct solutions, some more optimal than others.

It was difficult for students to acquire a global vision of how to carry out a structural project from the beginning. The coursework always had a very specific bounded and marked statement related to the direct application of the existing code regulations for design. This fact had its advantages because it facilitated the development of the work by students, but it had the disadvantage that they skipped the conception design phase of the structure. In addition, to solve this coursework, some of the teams usually divided the tasks of the different sections of the statement among their peers, so that they did not acquire the overall vision initially planned. If they participated from its conception and in all its development, this work would then serve them as a guide in the final degree project, and for their future professional life.

In short, students learned to calculate, and some ended up being very good calculators, but they found very difficult to learn how to design, and also to start thinking as an engineer, which is one of our goals. To design implies more concepts and aspects than to calculate a concrete structure. A proper design requires thinking about the future: the immediate future (construction), the mid-term future (serviceability and maintenance) or the long-term future (demolition and recycling or decommission and reuse). A global strategy must be considered to ensure the durability of the structure throughout its lifetime. This affects the design of the structure, material selection, analysis, construction and maintenance.

Once students finished the RC subject, when they had to face the development of a civil engineering project, for instance the final project of the bachelor, some students were disoriented because they knew how to solve specific particular cases but it was difficult for them to move on and face the globalism of the project.

Finally, in the 4th year, some students take the optional subject of Prestressed Concrete (4.5 ECTS), which is an excellent complement for students who are interested in the project and construction of structures. The context of this subject is different, because although it is a similar topic, it is optional, and it is observed that students have a greater interest in learning (they have chosen it in their itinerary and it is not mandatory). In addition, the lower number of students, compared to the compulsory subjects, allows a greater interaction. It has been observed that at the beginning of the course, some students have forgotten some aspects of the previous course (Reinforced Concrete, 3rd year), which makes us think that these students have studied for the exam and have not assumed the concepts.

1.6. Study Objectives and Research Questions

Taking into account the didactic characteristics by developing a PBL based approach, the research questions are:

  1. 1.Did the students improve their learning and future professional skills by implementing the PBL strategy in the Reinforced Concrete (RC) subject? 

  2. 2.Did the students improve their assessment in the RC subject? 

To analyze the impact of PBL in the subject of Reinforced Concrete of the Bachelor in Civil Engineering at the [University], the evolution of the final grades before and after applying PBL has been studied. In addition, the exam and project grades have been analyzed for the class group. The grades of the 2015/16 academic year before PBL implementation were compared to those obtained in 2016/17, 2018/19, 2019/20 and 2020/21 academic years.

In addition, two surveys were collected during years 2016/17 and 2018/19 (after the implementation of PBL) and some interviews were conducted with students who had experienced this methodology.

The analysis of these evidences allowed to study if there is an improvement on the students learning and also on their performance. Moreover, the surveys and interviews allowed us to identify the weaknesses of this method and to propose improvements for the following editions.

Finally, this research contributes to increase the application of active methodologies in Civil Engineering, and in particular in Concrete Structures courses. It will be useful for other researchers interested in the application of PBL in subjects of Civil Engineering programs. By applying these active methodologies, it is intended to increase the interest of the students in the topic, to enhance the achievement of competences and finally, to improve the academic results.

2. Methodology

2.1. PBL implementation

In this teaching context and in order to increase motivation and active attitude of students, and to improve their critical spirit and their global vision of a structural project from its conception, more similar to the professional exercise, a project-based learning methodology was introduced in the last editions (2016/17, 2018/19, 2019/20, 2020/21, 2021/22) of the Reinforced Concrete subject. PBL was not applied during the 2017/18 academic year due to coordination reasons.

During the course, a project of a real infrastructure was developed by students in the classroom and from it, the need to explain the theory arises.

The first edition of PBL (year 2016/17) was developed with few resources, but the experience was enriching, and possible improvements and shortcomings were identified for next editions. In this case, a course project of a pedestrian bridge with a continuous reinforced concrete deck supported on piers and abutments at both ends was proposed. The footbridge should cross the AP-7 highway between Vallgorguina and Santa Maria de Palautordera (Barcelona, Spain), parallel to the existing road bridge shown in Figure 1. The theory explained in the previous class sessions was put into practice during the workshops. However, the number of workshops dedicated to the project was quite small because only a few master classes were eliminated.

 

Figure 1. Course project of a pedestrian bridge crossing the AP-7 highway (year 2016/17)

In the following editions, a project of a real structure has been assigned to the students during the first week of class. The aim of this project is that students learn to deal with the definition of a solution from its conception trying to understand the problem they are solving, considering not only the structural typology and geometrical contour conditions but also other aspects such as aesthetics, landscape integration, social impact. In addition, they should define the structural solution with enough details as if it was going to be built.

It is important to point out that the coursework developed by students is a real life project, that is, a project which is under public tender by a local Administration or a project which has been announced by the Administration through some media. Therefore, students are more motivated since they know that they are trying to solve a real problem. An example of this is the project of the 2018/19 academic year consisting on a pedestrian bridge at Can Quiseró (Masquefa), which is a real project tendered by Diputació de Barcelona which was built and inaugurated in 2020, as shown in Figure 2 (Diputació de Barcelona, 2020).

 

Figure 2. Course project of a pedestrian bridge at Can Quiseró (Masquefa)
(year 2018/19) (Diputació de Barcelona, 2020)

This coursework should be developed by working together in teams of three people. Therefore, students develop the generic skill of teamwork and in addition, they will experience the way they will work in a professional environment. During the current editions, all groups had a general common statement. The project was in a certain town, in a certain area and it was required to design an infrastructure to solve a certain need, which must be justified by students from some data provided. The structural solution was not limited, and it was allowed to students to develop the one they believe was most optimal, with a reasonable justification. Therefore, the solution proposed by each group was different, leaving them freedom to implement the solution that each group deems most convenient. For future editions, we would like to raise the possibility that the students will identify problem statements by themselves and let them try to develop an infrastructure that can solve this problem.

The full course planning was published in the virtual campus on the first day of the course, so that students were aware of when the master classes took place, and how they should progress in the project as they knew when the project workshops and partial deliveries were supposed to be.

This PBL approach required a rescheduling of the subject, so that students developed the project in class based on theoretical bases that were explained throughout the course during master classes or with supporting teaching materials. Some topics (related to the basis for design for example) were learned individually outside the classroom from the teaching material available at the virtual campus and afterwards, class activities such as online tests were carried out to check if the student has internalized the main concepts.

A significant number of face-to-face classes were devoted to conducting workshops to develop the project. These workshops were compulsory. A guided presentation was given at the beginning of the workshop and the students should work with their teams in the development of the project. Some specific objectives were advised at the beginning of each session, and the students progressed in the project development by fixing their own learning pace. In between workshops, there were master classes related to the theory required for the following workshop.

Prior to starting the project development, a site visit or seminar with a construction engineer was planned, as well as a seminar/workshop with a design engineer. During the site visit, students will set their knowledge related to the execution of structures. The seminar/workshop with a project design engineer will focus on the structural conception and the process of developing a project, rather than on the structural analysis itself. During the 2016/17 academic year, a workshop on conceptual design was held with the collaboration of engineers from the Dobooku Association (www.dobooku.com). Although the result was quite interesting, it was difficult for students to be encouraged to make proposals. Figure 3a shows a photograph during the workshop, where students were divided into groups of three or four people, to work on the approach of conceptual solutions to a particular existing problem, in this case, the need to widen a road to include a bike lane in the area where there is an existing bridge, where the existing deck needs to be widened. A conceptual map was developed, with the existing contour conditions for the definition of the solution (see Figure 3b).

Figure 3. a) First workshop related to conceptual design (year 2016/17); b) Conceptual map developed
by one of the groups (in Spanish language) during the workshop

For the following editions, this workshop has been included in the coursework development and the structural or design engineer gives a seminar explaining his/her experience and philosophy when designing structures.

The coursework was planned in three steps:

  1. 1. Conception of the structural solution; 

  2. 2.Development of the structural solution: 

    1. a.Predesign of geometry and passive reinforcement; 

    2. b.Design of the geometry and passive reinforcement of all the structural elements. Verification of the ultimate and serviceability limit states; 

  3. 3.Others: Development of plans, brief description of construction procedure, bill of quantities, and contribution to sustainability. 

During step 1, the structural solution was developed conceptually, as a contest of ideas. During the first workshop, students developed a conceptual map setting down the different aspects that should be considered in a real project. Then, the conceptual solution was treated, the problem, the need for the project was identified and the main aim was to develop two or three alternatives to solve the existing need. After analyzing the landscape and by using the topographic map, students should establish a list of contour conditions. Considering the different contour conditions, students should sketch up possible alternatives, and should define the plan view and elevation of the infrastructure. Afterwards, they should choose the best alternative by a simple multiple criteria analysis.

This first step allowed the student to learn about the dynamics of PBL. Each group should establish some general rules for the teamwork that should be delivered. At the end of the semester, students should check if they and their colleagues have fulfilled all the rules and should submit this assessment. The teacher established a protocol for detecting possible problems in teams and for solving conflicts.

Once the geometry of the solution was defined, a session was held in which the different groups briefly presented their solution to the rest of the classmates, who raised possible suggestions, showing his/her critical thinking.

During step 2 as the project progresses, milestones and partial deliveries were established. In the first workshop of step 2, students should predefine the dimensions of the structural elements (deck, piers and abutments in the case of a bridge). Afterwards, students should develop a structural model in order to obtain the envelopes of axial forces, shear forces and bending moments for the ultimate and serviceability limit state combinations using a commercial program.

Then, in following workshops, teams should calculate the internal steel reinforcement accomplishing the different ultimate and serviceability limit states. During workshops, students worked with their team, applying the theory explained in class, under the supervision of the teacher. Students interacted with the teacher who gave feedback about the results they were getting during the workshop and answered all their questions. In addition, if there was the need in between workshops, each group could fix particular appointments with the teacher, to check and supervise their advances.

Deliveries of step 2 were related to: a) Establishment of the basis of design and envelopes of forces; b) Definition of the passive longitudinal reinforcement through the verification of the Ultimate Limit State (ULS) of bending with or without axial forces and of the ULS of instability; c) Definition of the transverse reinforcement by checking the ULS of shear; and d) Verification of the Serviceability Limit States (SLS) of cracking and deformation. In order to verify the ULS and SLS, students either prepared spreadsheets or were provided with existing sheets. Therefore, they were able to perform possible iterations in the solution.

These deliveries allowed the groups to carry out the work continuously over time, and not to wait until the end of the semester to develop it. In addition, the feedback given after each delivery, allowed them to arrange possible errors and make improvements during the project. The teacher could check if the whole group is working or only some of the members are working on it.

For the development of step 3, the teacher provided standard drawings of geometry and reinforcement, and a template for the bill of quantities. Drawings included the necessary details of geometry and passive reinforcement (see Figure 4 for year 2016/17). These drawings were perfectly defined in order to make a quick economic assessment.

The quantities in terms of m3 of concrete, m2 of formwork, and kg of active and passive reinforcement, as well as the global bill of quantities (€) were delivered at the end of step 3.

At the end of the course, students submitted a report of the analysis, drawings of the geometry, schematic drawings of internal longitudinal and transverse reinforcement distribution, the bill of quantities and a justification of the project.