Design–Build–Test in a First-Year Civil Engineering Laboratory: A Thin-Cardboard Truss Bridge Case Study

Abstract This case study describes the implementation of a resource-light design–build–test laboratory project embedded in a first-year civil engineering course, where many students begin with limited competence in statics and mechanics. Student teams designed and fabricated a thin-cardboard truss bridge under geometric constraints and a strict self-weight limit. Bridges were tested to failure using incremental loading with force and displacement measurements. Required deliverables included a force–displacement plot, failure-mode documentation, and a short reflection linking observed behavior to introductory mechanics concepts. An optional, supervised body-weight proof demonstration complemented the instrumented test as a human-scale illustration of resistance and stiffness. To examine the usefulness of the implementation, evidence was collected through anonymous pre- and post-activity surveys (pre: N = 107 ; post: N = 111 , representing response rates of approximately 71% and 74% of the ∼150 eligible students), a retrospective alumni survey (years 2–4; N = 58 , representing approximately 21.4% of the ∼270 eligible students from prior cohorts), and team-level performance logs. Both surveys were administered to the same first-year cohort, but participation was voluntary and attendance-dependent at two separate laboratory sessions. Some students who were absent during the presurvey administration completed the postsurvey, while some presurvey respondents did not participate in the postsurvey. No students from other cohorts were included. Because responses were anonymous, the two samples were overlapping but nonidentical, and pre–post analyses are therefore reported as unpaired cohort-level comparisons. The case study reports observed patterns in conceptual understanding, self-efficacy calibration, teamwork, and perceived relevance and summarizes implementation lessons and conditions that can support replication in similar first-year settings. Findings are consistent with the activity supporting the interpretability of load paths, stiffness, and failure mechanisms for students, while providing a scalable, low-cost protocol for early structural education.