Traditional glulam beam connection mode has a weak ability to transfer bending moment, leading to insufficient joint stiffness and mostly in the form of simply supported beams. To make full use of material strength, a novel prestressed glulam continuous beam was proposed. On this basis, this paper put forward a new method to further improve the mechanical performance of the beams by controlling prestress. According to the estimated ultimate loads of the beams, six different control range values were formulated, and 12 continuous beams were tested for flexural performance. The effects of prestressing control on the failure modes, ultimate load capacity, and load versus deformation relationships of the glulam continuous beams were analyzed. The test results indicated that the flexural performance of the beams with prestressed control was significantly improved compared to the uncontrolled beams, the ultimate load was enhanced by 13.60%–45.11%, and the average steel wire stress at failure was increased from 70% of the designed tensile strength to 94%. Combined with the finite element analysis (FEA), the reasonable control range of the prestressed control continuous beams was18%–30% of the estimated ultimate load. The research in this paper can provide references for the theoretical analysis and engineering application of similar structures.

The limited transferring moment capability of Glulam (glued laminated wood) joints results in insufficient joint stiffness. Therefore, most of the connections are hinged joints. Based on the previous studies, one novel end‐connection device was proposed to form prestressed continuous Glulam beams. The prestressed beams were composed of prestressed low‐relaxation steel bars, the deviator block, the anchorage device, and the novel end‐connection apparatus. These prestressed steel bars were tensioned by the deviator block to exert prestress. Then, 18 prestressed continuous beams and two prestressed simply supported beams were subject to the bending tests to explore the impact of reinforcement ratio and prestress on the prestressed Glulam beams from aspects such as failure modes, bearing capacity, load‐deflection relationship, and load‐strain relationship. The results show that, given the same prestress level, compared with beams with a reinforcement ratio of 1.92%, the bearing capacity of beams with a reinforcement ratio of 3.84% and 5.76% is increased by 20.3%–29.4% and 30.51%–36.36%, respectively. Given the same reinforcement ratios, compared with beams without prestressing, the bearing capacity of beams with a prestressing force of 7 kN and 14 kN is increased by 2.39%–10.14% and 6.49%–13.26%, respectively. In addition, compared with simply supported beams, the bearing capacity of continuous beams is increased by 40%, and the deformation is reduced by 13%. Therefore, as a novel prestressed beam, the bending performance of Glulam beams can be improved effectively.

Creep is an important characteristic of bamboo and wood materials under long-term loading. This paper aims to study the long-term bending behaviour of prestressed glulam bamboo-wood beam (GBWB). For this, 14 pre-stressed GBWBs were selected and subjected to a long-term loading test for 60 days. Then, a comparative analysis was performed for the effects of pretension values, the number of pre-stressed wires, and long-term load on the stress variation of the steel wire and the long-term deflection of the beam midspan. The test results showed that with the number of prestressed wires increasing, the total stress of the steel wire in the beam midspan and the ratio of the long-term deflection to the total deflection decreases decreased, but when the number of steel wires exceeded 4, the total stress and long-term deflection was less influenced; with the pre-tension value increasing, the ratio of the total stress of the steel wire in the beam midspan and the ratio of the long-term deflection to the total deflection also decreased, but when the prestress force was greater than 3.975 kN, the total stress and long-term deflection were less affected; with the other parameters unchanged, when the value of the long-term load increased, the total stress of the steel wire decreased, and the long-term deflection of the beam midspan increased, which shall be more significant with the long-term load greater than 30% of the standard ultimate bearing capacity. After the test, the experimental data were fitted, and the creep coefficient was given. Finally, the long-term stiffness calculation formula of the pre-stressed GBWB based on creep effect was proposed. The research findings have certain theoretical significance and engineering value.

The study of the long-term behavior of the prestressed continuous beam is vital for the design and the appliance of wood structures in engineering. In this study, long-term experiments were first conducted to determine the long-term creep behavior. Afterward, the prestress of the long-term beam was regulated to the initial state, and we carried out short-term flexural experiments to explore the effect of prestressing regulation. The influences of prestressed value and the number of prestressed steel wires on the mechanical properties of the continuous beam were investigated and discussed. The experimental results demonstrate that the creep reduced the stress in the steel wires, weakened the effect of prestressing, and increased the tensile stress at the bottom of the beam, which led to a reduction in the bearing capacity of the beam. The prestressing regulation could increase the moment arm, so the bearing capacity of the beam was improved.

In recent years, extensive attention has been drawn to prefabricated buildings, particularly wood construction. Glulam beams are the major supporting components of modern wood buildings. Since the force arm is the most critical indicator to evaluate the resistance moment of the glulam beam string structure, it is necessary to further study the influence of the force arm on the mechanical properties of the glulam beam string structure. We tested the flexural performance of 15 prestressed glulam beams, which were divided into two groups (A and B) to, respectively, research the influences of the string arm and the end arm on the bearing capacity, failure mode, stress distribution, and deformation performance of glulam beams. The results showed that when the height of the end arm remained constant and the string arm increased from 90 mm to 130 mm and 170 mm, the bearing capacity of the beam increased by 6.77% and 17.22%, respectively. Moreover, as the depth of the compression zone of the glued timber beam gradually increased, the failure mode of the beam changed from the brittle tension failure of the beam bottom to the ductile compression failure of the beam top. When the height of the string arm remained constant and the end arm increased from 10 mm to 30 mm and 50 mm, the bearing capacity of the beam increased by 4.27% and 8.13%, respectively. The beam had no significant change in the failure mode, while it could bear the stress more uniformly. Based on the experimental results and principles of equilibrium, moment equilibrium, and similar triangle, we calculated the ultimate bearing capacity of the glulam beam and proposed a design method for durable wood structures.