Experimental investigation on shear behavior of full-scale glued laminated bamboo beams under three-point loading test and using digital image correlation technique

Abstract

Applying bamboo in construction is expected to reduce carbon footprint and promote environmental protection. Very limited information is available in the literature about the shear behavior of glued laminated bamboo (glubam, i.e., a type of engineered bamboo) beams. To this end, this paper presents an experimental investigation of shear behavior for full-scale glubam beams using three-point loading test. Fourteen specimens were tested, considering the effect of shear span-depth ratio (a/d) and beam depth on the shear response of glubam beams. Digital Image Correlation (DIC) technique was conducted to measure the strain fields on two specimens with different shear span-depth ratios. The test results show that the glubam beams with a/d= 1.0 occurred local compressive damage at the loading region and the mixed local compression-flexure damage; and beams with a/d= 2.0 exhibited flexure-dominated damage together with a minor local compressive settlement at the loading region. Specifically, increasing the shear span-depth ratio reduces the load capacity but improves the ductility and minimizes the global damage in the glubam beam. Larger shear area of the beam has a smaller shear stress, which demonstates the scale effect on the shear behavior of the glubam beam. DIC technique is feasible for monitoring the shear behavior of glubam beams with a small shear span-depth ratio. Meanwhile, this technique can also be employed for the beams with a relatively large shear span-depth ratio to monitor the shear behavior at a relatively small deformation.