Experimental Research On Flexural Performance Of Reinforced Glulam Beams

At present, under the influence of energy saving and environmental protection ideology in the whole world, with the unique features of green natural and low-carbon environment, the timber structure has been widely favored. With the gradual development of modern timber structure, people have more and more requirements on timber structure. To realize the purposes of saving wood cost, improving the utilization ratio and utilization span and improving the self defect of glue-lumber beam, the common reinforced glue-lumber beam was put forward in the paper, as well as the prestressed reinforced glue-lumber beam, which can be convenient for engineering application, apply prestress accurately and realize regulation at any time.Through the bending tests of 12 common glue-lumber beam,9 common reinforced glue-lumber beam and 9 prestressed reinforced glue-lumber beam, the influence of reinforcement number and pre-tension value to glue-lumber beam bending were researched, which can obtain the ultimate load、 failure mode、 load-deflection relation curve and load-strain relation of beam. The results showed that:compared with common glue-lumber beam, the bending ultimate bearing capacity of common reinforced glue-lumber beam improved by about 30.0%, the stiffness increase amplitude was 8.0%-34.0%. When the reinforcement number was more, the bending stiffness of glue-lumber beam was bigger and the span-deflection was smaller; compared with common glue-lumber beam, the bending ultimate bearing capacity of prestressed reinforced glue-lumber beam improved by 31.3～64.4%, the bending stiffness improved by about 33.3%. When the reinforcement number was the same, with the increase of pre-tension value, the was bigger, the deflection of prestressed reinforced glue-lumber beam after loading was smaller, the ultimate bearing capacity of member increased, and the bending stiffness was basically unchanged, which can have better use of wood compressive strength and steel bar tensile strength, effectively decrease the deflection deformation of beam, and behave obvious plastic damage characteristics when damaged. In the process of test, the strain variation of test beam cross section accorded with the plane section assumption. When the bearing capacity was the same, the common reinforced glue-lumber beam can save wood by 13.3%～14.7% and save cost by 6.5%～8.0% when compared with common glue-lumber beam, the prestressed reinforced glue-lumber beam can save wood by 15.1%-28.2%and save cost by 7.0%～16.5%.By the ABAQUS finite element analysis, the glulam beams of finite element simulation analysis model was builded.Respectively to study the reinforcement quantity and the influence of pre-tension value size of glulam beams, the analysis results was consistent with test results.