粘贴钢板加固木梁试验研究

Experimental study of timber beams strengthened with steel plates

对8根木梁粘贴钢板加固进行对比试验研究,其中3根为对比试件,5根为粘贴钢板加固木梁试件,试验参数包括钢板厚度(3或5mm)、钢板层数(1或2)和是否采用螺栓锚固。研究结果表明:粘贴钢板加固木梁的极限承载力有明显提高,提高幅度为9%～141%(平均提高60%);其中采用螺栓锚固的粘贴钢板加固木梁的极限承载力提高幅度更大,平均提高88%。加固木梁的极限位移亦明显提高,提高幅度为16%～139%(平均提高61%)。粘贴钢板加固木梁试件的初始弯曲刚度亦有较大提高,提高幅度为32%～158%,其中粘贴一层5mm厚钢板的加固木梁提高最多。粘贴钢板加固木梁跨中截面仍基本符合平截面假定;在相同荷载作用下,加固木梁受拉边缘钢板拉应变和受压边缘压应变明显小于对比试件。粘贴钢板加固木梁并用螺栓锚固是一种有效的加固方法。

An experimental study in which eight timber beams were tested, including three reference unstrengthened beams and five beams strengthened with steel plates externally bonded to the tension face. The test parameters include thickness （3 or 5 mm） and number （1 or 2） of steel plates, and screw bolts for additional anchoring of steel plates. The test results show that the ultimate flexural strength of timber beams increase by 9%-141% （with an average value of 60%） and the ultimate displacement increase by 16%-139% （with an average value of 61%） due to strengthening. When the steel plates are anchored by screw bolts, the average increase of strength is 88%. The initial stiffness of the strengthened beams also increase significantly by between 32% and 158%, depending on the thickness and number of strengthening steel plates used. The strain distributions along the height of the strengthened beams at middle-span are nearly linear during the whole loading process and so a plan section remains almost plan. This study shows that strengthening timber beams with steel plates anchoring with screw bolts is a very promising strengthening technique.