体外预应力胶合木梁抗弯性能试验研究

Experimental study on the flexural behaviors of external prestressed glulam beams

为研究体外预应力胶合木梁在静载作用下的受夸}生能，开展了21根胶合木梁的试验，其中包括未增强、非预应力增强和体外预应力胶合木梁；通过改变张拉控制应力的大小、转向装置撑杆高度、胶合木梁截面形式，研究木梁破坏形态与破坏机制，对比分析了不同构件的极限承载力与抗弯刚度等结构性能。结果表明：增强或预应力构件的破坏形式主要表现为受压区屈服破坏；相比未增强胶合木梁，非预应力增强胶合木梁的受弯极限承栽能力和刚度分别提高了26．5％和17．6％，而预应力增强胶合木梁则分别提高了28．8％-81．8％和44．9％；此外，通过改变撑杆高度及优化木梁截面，也可显著提高木梁的结构性能。

A total of 21 glued laminated timber （glulam） beams were tested to determine the flexural behaviors,which includes unreinforced control beams, passive reinforced beams and external prestressed beams.Influencing parameters such as control stress for prestressing, height of steel deviator and cross- sectional shape of glulam beams were taken into consideration.The failure modes and failure mechanism were discussed, and then the ultimate loads and the flexural st/finesses of both reinforced and prestressed beams were compared with those of unreinforced control beams.The test results showed that the typical failure mode is the timber yield failure in compressive zone for reinforced and prestressed glulam beams. Compared to the unreinforced control glulam beams, the ultimate loads and flexural stiffnesses of reinforced beams increased by 26. 5% and 17.6%, respectively. While the improvement was 28.8% - 81.8% and 44.9%, respectively for external prestressed members.In addition, through the optimization of the deviator height and glulam cross-section, the flexural behaviors of the glulam beams can also be moderately increased.