Analytical model for prestressed glulam beams reinforced with unbonded steel bars

Abstract

Glulam beams reinforced with bonded steel bars are a common form. The study describes theoretical models of unbonded reinforced and prestressed reinforced glulam beams for assessing the reinforcement ratio and prestress level range, and for predicting the effect of unbonded steel bars on the flexural capacity of the beam. Considering the stress changes of beam cracking and cross-sectional stress, the minimum and maximum reinforcement ratios were determined. On this basis, the influence of the service load on the beam in the actual engineering was explored, and the force equilibrium equation was established to derive a reasonable prestress range related to the reinforcement ratio. Combined with the glulam constitutive model, and analyzed the strain distribution of unbonded steel bars was to establish the flexural capacity prediction model. The accuracy of the model was verified by the relative error between the prediction and test values ranging from-11.78% to 8.84%.