Experimental investigation of the bending creep behavior of glulam beam reinforced with near surface mounted steel bars

In this study, the pull-up tests of glued-in steel bar were conducted, and the results showed that ensuring the anchorage length of the steel bar can obtain desired mechanical behavior of the glued-in steel bar. The creep tests were performed on two unreinforced glulam beams with different stress ratios and four glulam beams reinforced with near surface mounted steel bar. After 65-day test periods, the test results found that mounting the steel bar at both compression and tension sides of the glulam beam can decrease the creep coefficients by at least 0.32 when compared to the unreinforced glulam beam. By employing the power function, Burger and proposed modified model, it was found that the proposed modified model had the best goodness of fit, followed by thepower function model. Through the analysis of the creep coefficients predicted by the modified model, it was found that values of the creep coefficients for the reinforced glulam beams were almost half of those for the unreinforced glulam beams. Thus, it was recommended that the glulam beam reinforced with smaller diameter steel bar mounted at compression or tension side can be usedfor the long-term design of the glulam beam in practice.