Design and Development of a Portable Manual Rebar Stirrup Bender

Manual stirrup fabrication remains common in small construction projects, training workshops, and locations where powered rebar-bending equipment is unavailable or impractical. Improvised bending methods, however, can demand substantial physical effort and produce inconsistent results. This study developed and evaluated a portable manual rebar stirrup bender intended for construction and instructional use. A developmental, descriptive-evaluative design was employed at Palompon Institute of Technology during Academic Year 2025–2026. The prototype combined a rigid steel base, adjustable positioning and clamping elements, forming and support pins, and a lever-operated bending assembly. Development proceeded through planning, design, material procurement, fabrication, assembly, initial trials, adjustment, final functionality testing, and user evaluation. Forty purposively selected respondents—20 steelman workers and 20 faculty members from the College of Technology and Engineering—rated the device using validated researcher-made checklists and a five-point acceptability scale. Weighted means summarized design adequacy, performance, satisfaction, and proposed improvements. The design specifications and features were rated Acceptable (M = 4.03), while overall performance was Highly Acceptable (M = 4.21). Functionality (M = 4.31) and portability (M = 4.27) were the strongest performance domains; durability (M = 4.15), ease of operation (M = 4.16), and safety (M = 4.16) were Acceptable. Overall user satisfaction was Acceptable (M = 4.07), and the consolidated evaluation was Acceptable (M = 4.12). Respondents most strongly recommended protective covering (M = 4.30) and corrosion-resistant materials (M = 4.25). The documented material and fabrication budget was PHP 6,938. The prototype was positively received as a low-cost, non-electric bending aid, but the evidence is primarily perceptual. Objective measurements of bend geometry, operating force, cycle time, allowable bar sizes, fatigue life, and comparison with conventional methods are required before claims of structural compliance, productivity gain, or long-term field reliability can be made.

rebar bending; stirrup fabrication; portable construction tools; manual bending device; product development; usability evaluation; occupational safety; metalworking education

1. American Concrete Institute. (2023). Building code requirements for structural concrete and commentary (ACI 318). American Concrete Institute. [Google Scholar] [Crossref]

2. ASTM International. (2023). ASTM A615/A615M-23: Standard specification for deformed and plain carbon-steel bars for concrete reinforcement. ASTM International. [Google Scholar] [Crossref]

3. Brown, T. (2008). Design thinking. Harvard Business Review, 86(6), 84–92. [Google Scholar] [Crossref]

4. Budynas, R. G., & Nisbett, J. K. (2020). Shigley's mechanical engineering design (11th ed.). McGraw-Hill Education. [Google Scholar] [Crossref]

5. Concrete Reinforcing Steel Institute. (2022). Manual of standard practice. Concrete Reinforcing Steel Institute. [Google Scholar] [Crossref]

6. Hibbeler, R. C. (2020). Mechanics of materials (11th ed.). Pearson. [Google Scholar] [Crossref]

7. International Organization for Standardization. (2019). ISO 9241-210:2019 ergonomics of human-system interaction—Part 210: Human-centred design for interactive systems. International Organization for Standardization. [Google Scholar] [Crossref]

8. Likert, R. (1932). A technique for the measurement of attitudes. Archives of Psychology, 22(140), 1–55. [Google Scholar] [Crossref]

9. Sanders, M. S., & McCormick, E. J. (2019). Human factors in engineering and design (8th ed.). McGraw-Hill Education. [Google Scholar] [Crossref]

10. Ulrich, K. T., Eppinger, S. D., & Yang, M. C. (2020). Product design and development (7th ed.). McGraw-Hill Education. [Google Scholar] [Crossref]

• Room Safety Monitoring Using a Temperature Sensor Alarm System
• Motion Activated Automatic Garage Door System
• Instrumentation & Control of Green Hydrogen Production Plant
• Evaluating the Effectiveness of an MS Project Webinar in Enhancing Construction Students’ Digital Scheduling Awareness, Perceived Usefulness, and Future Industry Readiness