Digital Technologies have evolved significantly, playing a crucial role in the design of structural elements with higher accuracy than conventional methods !
Ranjitha Rajagopal, our next pathbreaker, Structural Engineer at COWI (Gothenburg, Sweden), designs reinforcements inside concrete structures in buildings to ensure that they can bear the load these structures are subjected to.
Ranjitha talks to Shyam Krishnamurthy from The Interview Portal about her masters thesis at IIT Madras on construction materials using non-contact optical techniques that sparked her interest in structural engineering.
For students, explore and build a deeper understanding of the concepts rather than just scoring grades. The earlier one learns to ask questions the faster the learning curve is !
Ranjitha, what were your growing up years like?
I hail from Palakkad, Kerala. My initial schooling was from Kendriya Vidyalaya Kanjikode, Palakkad. My dad is a banker and my mom works in the Insurance sector. When I was 12 my parents took a job transfer to Kottayam where I continued my school years at Kendriya Vidyalaya Rubber board.
During my school years, I had a keen interest in physics and Mathematics. My parents were also math enthusiasts who nurtured my interests further and made learning Math even more fun. Looking back, I remember how Geometry and trigonometry caught my interest during the early school years. They are very much a part of my daily work today.
What did you do for graduation/post graduation?
I pursued my undergraduate degree (B.Tech) in Civil Engineering from Government Engineering College Trichur (GECT) and post-graduation (M.S) in Building Technology at Indian Institute of Technology Madras.
Master of Science (M.S) after engineering is a relatively less ventured path in India. Unlike M.Tech, M.S. is a research based post-graduation degree. The course involves comparatively less course work and more time dedicated to a thesis. The thesis objective must be research focused and not an application of the course work. Pursuing M.S. in IIT Madras was a good learning opportunity. It taught me to think outside the box, to design experiments, and execute them, and more importantly, to deal with uncertainties.
What were the key influences that led you to such an offbeat, unconventional and uncommon career?
I graduated from school during a decade when professional courses were on the rise and society in general leaned towards Engineering or Medicine as the sought-after courses for a bright future. Being keen on physics and mathematics naturally led me to engineering as a possible career option.
During the last two years of school, I started reading about different engineering branches from various career magazines and seeking information from career counseling sessions. My first choice of study was Architecture. However I could not secure an admission in Architecture out of the 100 seats that were available in the state back then. That led to my second and the only other option I was interested in, which was Civil Engineering.
In hindsight, I had very little idea about a civil engineering career when I chose it for my undergraduate degree. I believe that my real interest in civil engineering developed during my academic years and largely after I started working in the industry. It was through several academic activities, professors and mentors at work who shaped my interests and aspirations in the field.
How did you plan the steps to get into the career you wanted? Tell us about your career path
During the third year of B.Tech I decided to do post-graduation in courses related to structural engineering. I started attending coaching classes for GATE along with my regular classes at college. It was during the final year when I along with a classmate got selected for a presentation competition at IIT Madras. While we were at IIT we had an amazing opportunity to meet the faculty in different departments and discuss post graduation opportunities at IIT. That is when I got to know about a research based alternative degree (M.S) that IITs offer. I was fortunate to talk about this course with a few professors in the BTCM (Building technology and construction management) as well the structural engineering department. I had already received my gate score by then and luckily qualified for the cut-off for the M.S. interview. Unlike M.Tech, M.S. has much fewer vacancies. I gave the interview after a few months after my first IIT-M visit and got selected to BTCM department along with 5 others.
The first step after admission to M.S. course at IIT is to select your supervisor for thesis. The M.S. requires completion of 5 courses (which is much less courses compared to M.Tech which is almost 15 courses). The courses are decided based on your supervisor’s line of work and your subject for the thesis which varies for each M.S. student. The courses can be inter disciplinary, you can chose any course offered by any of the 20+ departments in IIT if it helps your line of thesis. My line of thesis was on corrosion of reinforcement embedded in concrete. For my M.S thesis – Design of prestressed concrete and probability methods, I chose three courses from the same department (BTCM) which deals with durability of concrete structures, advanced materials and maintenance and rehabilitation of concrete structures, and two courses from structural engineering department. A mix of courses from BTCM and structural department helped me in understanding my thesis subject and finding applications from both a durability and structural point of view. The course in probability helped me to design my experimental studies. The research evolved to be interdisciplinary and in course of time I had my co-supervisor from the department of engineering design. My co-supervisor’s line of work was Digital Image Correlation (DIC). DIC is a non-contact optical technique which can measure deformations over a predefined region. My experiment specimens were corroded rebars that were collected from an old structure. My experiment involves doing a tensile test on these corroded rebars which involved pulling the rebars to their breaking point and measuring their strength and ductility to understand the effect of corrosion on these structural parameters. The corroded rebars have a very non-uniform surface which posed a limitation for conventional methods of measuring deformation in the specimens during the tensile test. That is when the DIC came in handy.
My research objective evolved during the three years of the degree. Its very rare to find a M.S research scholar who has a very defined objective from the beginning. On being exposed to DIC, my research objective changed to Assessment of stress-strain behavior of corroded steel rebars using digital image correlation technique. The thesis involved an extensive pre-study to assess the feasibility of DIC for assessing the mechanical behavior of corroded rebars. DIC was originally used in the Engineering Design department to assess the behavior of membranes, films etc where the area of interest were at a much smaller scale (upto 1 cm-square). In civil engineering the experiment specimens are much larger and thus the accuracy of DIC when focused on a larger area of interest was something that needed to be investigated first. I could achieve a higher accuracy than any conventional methods when DIC was paired with 3D scanning of the specimens to achieve any very accurate measurement of cross-section of the non-uniform corroded specimens.
After my M.S., I wanted to get into the industry and work on construction projects. I moved to Sweden soon after graduating from IIT to be with my husband who was pursuing his doctorate in Gothenburg. I was fortunate enough to land at a job at Skanska within a month after arriving in Sweden. I was appointed as production engineer. In this role I worked on cost and material estimations in the tender phase of the projects. However, I was not entirely satisfied with my role here as it did not align with my line of studies.
After 6 months at Skanska, I moved to a precast manufacturing company called Strängbetong where I worked as structural engineer for precast structures. As a structural engineer, I worked on calculating and designing the precast structures for the required strength and durability. Precast structures are buildings or infrastructure built from structural elements (beams, columns, slabs, walls etc.) that are cast or manufactured in a factory, transported to the building site and assembled at the site (like lego blocks). Compared to the traditional cast-on-site construction, precast construction is a more efficient and faster method. It also involves a set of different design criteria and logistics to make precast construction possible.
My role at Strängbetong opened up new horizons and set me on a path that I continue on today. After a little more than five years, I moved to a consultancy firm, COWI, where I work today. I continue to work as a structural engineer for precast construction. The reason I moved on to consultancy is to broaden my understanding on projects. I work with engineers of other disciplines like foundation design and HVAC which helps me gain a holistic understanding of buildings.
How did you get your first break?
My first break in my career was when I was offered a job as a structural engineer at Strängbetong. My first job at Skanska was not in line with my academics and I was looking out for more suitable job opportunities. It was a friend who mentioned a career fair for students at university which he suggested I attend. Since I wasn’t a student, I was reluctant at first. I felt slightly out of place attending the event but soon enough I met a representative from Strängbetong and he suggested I talk to his manager.
I got called in for an interview when I sent in my CV to Strängbetong. The fact that I already had an employment helped in being shortlisted for the interview. Strängbetong is one of the leading precast manufacturers in Sweden. The degrees from India were very credible even though my employers had no clue about the credibility of the institutes I had pursued my studies from. I could not expect any edge for being an IITian as I expected earlier.
I was interviewed mostly on the structural engineering related courses I pursued during my B.tech and M.S., although there were hardly any technical questions. I was mostly assessed based on the questions I asked about the firm during the interview, and for my attitude towards work. This is something I have experienced in all the interviews I have been through so far, which is that a person is assessed for their attitude and engagement towards the profession than for the right answers to technical questions. It is greatly appreciated by the interviewers that the interviewee poses relevant questions about the job. It is equally important for the candidate to know the job and the company as it is for the interviewers to assess the candidate. After the interview at Strängbetong I was asked to complete a technical questionnaire which was sent via mail. The questionnaire assessed if the candidate can make plausible estimations to solve an engineering problem.
A week after handing over the answered questionnaire, I was offered the job. I started out at the beginner level as a civil engineer. Two years into the career I was promoted to the role of specialized structural engineer. My five years at Strängbetong involved a lot of learning opportunities. It was the excellent mentorship and the amazing work culture that helped me progress as a structural engineer during these years. My mentors at Strängbetong taught me to be curious and develop the courage to ask ‘Why’. The courage to admit my lack of knowledge in any subjects opened the doors to learn and become more competent in that area.
What were some of the challenges you faced? How did you address them?
Challenge 1: My very first challenge at work was to learn Swedish. The construction industry being very much connected to locals and the society, it is almost impossible to find a job where English is the working language. I was lucky enough to land a job with barely any Swedish proficiency. However, it proved to be exceedingly difficult at first to be surrounded by people speaking mostly only Swedish at work. I enrolled for evening classes to learn Swedish. The classes helped to understand the conversations around me but did not give me enough confidence to speak. I realized slowly that it was my mental block that was stopping me from speaking and learning Swedish.
I always considered my speaking skills to be one of my strengths which suddenly took a hit after moving to Sweden. My mental fixation regarding communication was what was stopping me from attempting to speak the language. That was the barrier I worked on overcoming and that helped me to speak Swedish and get better at it. 5 years down the line I have professional fluency in Swedish and feel confident to handle the language.
Challenge 2: My second biggest challenge was my reluctance to admit my lack of knowledge and to learn from it. When any new tasks came up I used to believe and project that I have a good idea about the task and how it is done rather than learn as a beginner. A few months into work, I realized my hesitance to admit my lack of knowledge in a subject was preventing me from acquiring knowledge. As soon as I learned to admit that I do not know a particular thing at work, without losing my self-esteem, my learning curve increased steeply. I developed a curiosity and enthusiasm to learn more.
Where do you work now? What problems do you solve as Structural Engineer?
I currently work as a structural engineer specialized in precast construction at a consultancy firm called COWI. My job deals with doing structural calculations for strength, stability and robustness of a building. I design reinforcement inside concrete structures or dimensions of steel structures to ensure that they can bear the load these structures are subjected to. I do calculations to ensure a building doesn’t sway too much or fail under wind or seismic loads. I ensure through calculations and design that a local failure in a structure does not result in a total collapse of the building.
Challenges I face at work are that, though every project is different, there are norms and standards to be followed while carrying out the structural design for every project. For precast structures, it would mean designing connections between elements in a way that conditions of the norms are fulfilled and/or suggesting changes in the structure or layout to make it structurally safe.
What skills are needed for your role? How did you acquire the skills?
The important skill sets I believe a structural engineering professional should have are
- clear understanding of the fundamentals
- good communication skills to understand the requirements and conditions of a project
- skills to collaborate with your team within the firm and with other disciplines.
What’s a typical day like?
When a project is assigned, a structural engineer starts with reading the project documentation and the accompanying architectural drawings. The scope varies from project to project. A project that needs to be worked from scratch has to be checked to verify if the bearings and dimensions provided by the architect are sufficient for the strength, stability and other performance criteria. Otherwise a structural engineer suggests the necessary changes which then have to be communicated with the architect and the client for their approval. After this step, a detailed calculation is performed to design the finer details like size of the precast elements, connections between the elements to make them into a unified structure, and reinforcements in the individual elements like walls, beams, columns etc. The information is then documented for the drafters so that necessary drawings are created and then sent out to the factory which then casts or manufactures these elements. The end product elements are then transported to the building site where they are assembled (like legos or building blocks) to form the designed building.
The most rewarding moment as a structural engineer is when I see the assembly of the building I designed. It is quite a revelation to witness how the millimeter scales in the drawings transform into a finished building. I try to visit most of the structures I have worked with, although it is not a requirement for my role. However my work in the project doesn’t end until the building is fully mounted. There could be certain details which do not comply fully with the drawings due to human error or errors during the casting process. A structural engineer is usually contacted by the site engineer to take remedial measures or provide alternative details. A structural engineer is required to submit a final design report of the building to the client as a reference for maintenance or future extension of the building. This marks the finishing point in a project.
What is it you love about this job?
What I love in this career is how I get to learn something new or advanced every day. Structural design is a field that is going through major digital transformation right now which makes it more interesting. Also, a major challenge in the field is to make construction more climate friendly. There are new and improved materials that are being developed to this end. I read and try to understand the advancements happening in the branch which inspires me to advance as a structural engineer.
How does your work benefit society?
Civil engineering is a field that goes hand-in-hand with the progress and development of society. As a result, I work closely with companies and people who use the buildings that we structurally design, for their workplace, for their commute or as their place of residence. That makes me immensely honored to be working in this branch of engineering. This job also comes with an immense responsibility to come up with the right design as it directly affects the occupants.
Tell us an example of a specific memorable work you did that is very close to you!
One of the most memorable projects I was a part of was the third highest industrial tower in Sweden which was constructed partly cast-on-site and partly with precast elements (beams and slabs). I was responsible for the design of the precast elements and for integrating them with the cast-on-site structures which proved to be a challenging task. I got an opportunity to work with a very competent team to come up with a very efficient design to make the assembly easier and to meet the hectic deadlines in this project.
Your advice to students based on your experience?
My advice to students would be to explore and to build a deeper understanding of the concepts rather than just scoring grades. The earlier you learn to ask questions and seek knowledge, the faster you will learn. Today’s world is very interdisciplinary, so rather than sticking to a plan early on in life, open up horizons for broader opportunities.
My primary aim is to keep learning every day. I wish to continue my experience to serve the society and be a part of sustainable construction and the digital transformations in the field. I see myself heading towards a role as a technical lead in precast within a few years. As much as I like to plan, I also remain flexible to evolve with time and embrace the developments in the field.