Bio-Based Polyurethane Elastomer for Strengthening Application of Concrete Structures Under Dynamic Loadings
Feasibility of application of a bio-based elastomeric polyurethane (PU) coating to improve the dynamic resistance of concrete specimens by enhancing their energy absorption capability was investigated. A series of experimental investigation were conducted using scaled concrete specimens with dimensions of 160 × 40 × 40 mm, which were coated with eight different coating configurations by varying the coating thickness and location. Three-point bending test was conducted under quasi-static and dynamic conditions, by varying the strain rates (0.00033 s−1 and 0.067 s−1). The maximum flexural stress, failure strain, and strain energy density characteristics were used to assess the effectiveness of the proposed retrofitting technique. Polymer layers of 1–4 mm thick provided 2.9–8.9 times enhancement in failure strain, 3.0–11.3 times enhancement in strain energy density, and a marginal enhancement in the maximum flexural stress under dynamic conditions compared to the dynamic response of uncoated concrete specimens. In addition, the dynamic response of concrete specimens was improved when the thickness of the PU coating was increased and when the coating was applied on both faces.
The authors would like to express their gratitude to the Ministry of Higher Education, Malaysia, and Universiti Kebangsaan Malaysia, for providing the necessary funding for this research through the FRGS Grant (FRGS/1/2015/TK01/UKM/02/1) and the ERGS Grant (ERGS/1/2013/TK03/UKM/02/6).
- 1.Somarathna, H. M. C. C., Raman, S. N., Mutalib, A. A., & Badri, K. H. (2015). Elastomeric polymers for blast and ballistic retrofitting of structures. Jurnal Teknologi (Sciences & Engineering), 76, 1–13.Google Scholar
- 2.Ngo, T., Mendis, P., Gupta, A., & Ramsay, J. (2007). Blast loading and blast effects on structures – An overview. Electronic Journal on Structural Engineering. Special Issue: Loading on Structures, 7, 76–91.Google Scholar
- 5.Somarathna, H. M. C. C., Raman, S. N. Badri, K. H., Mutalib, A. A., Mohotti, D., & Ravana, S. D. (2016). Quasi-static behavior of palm-based elastomeric polyurethane: For strengthening application of structures under impulsive loadings. Polymers, 8(5), 202, 23p.Google Scholar
- 9.Somarathna, H. M. C. C., Raman, S. N., Badri, K. H., & Mutalib, A. A. (2015). Analysis of strain rate dependent tensile behaviour of polyurethanes. In Proceedings of the 6th International Conference on Structural Engineering and Construction Management 2015. Kandy, Sri Lanka (7p).Google Scholar
- 11.Badri, K. H. (2012). Chapter 20, Biobased polyurethane from palm kernel oil-based polyol. In F. Zafar & E. Sharmin (Eds.), Polyurethane (pp. 447–470). Rijeka: INTECH.Google Scholar
- 12.Raman, S. N. (2011). Polymeric coatings for enhanced protection of reinforced concrete structures from the effects of blast (PhD Thesis). 308p. Department of Infrastructure Engineering, The University of Melbourne, Australia.Google Scholar