Experimental Study On Compressive Properties Of Long Columns Of Modified Fast-growing Poplar

Timber structure architecture has a history of thousands of years in our country.Most of these wooden structures are built with local materials,but due to the environment,resources and other reasons,the development of wooden structures in China is greatly restricted.In recent years,the wooden structure building has gradually returned to people’s sight,more and more people gradually like and pay attention to the wooden structure.Wood is greatly affected by the environment in the process of growth,so it needs to be strengthened or modified to improve the performance of wood in practical application,so that the fast growing poplar wood can be better popularized in the wood structure architecture and applied in the modern wood structure architecture,so as to provide a certain reference for the wood structure engineering.Through compression test was carried out on the 20 pillar of fast-growing Yang Muchang,considering the three kinds of modified enhancement approach,structural adhesive,steel plate and CFRP,respectively,on board thickness,thickness of steel plate,fiber ratio as a variable,the axial compression and eccentric compressive mechanical property test,the modified fast-growing Yang Muchang column of ultimate bearing capacity,failure form and so on has carried on the related research.The main conclusions are as follows:1.Compared with the long-column specimens of fast-growing poplar modified by structural glue,the load-bearing capacity of the long-column specimens of fast-growing poplar modified by structural glue increased greatly,and the deformation capacity was improved to a certain extent.With the decrease of the thickness of the plank,the bearing capacity increases.With the increase of eccentricity,the shear failure of the bonding surface occurred and the bearing capacity of the specimens decreased gradually.2.Compared with the long-column specimens of fast-growing poplar modified by steel plate,the axial compressive strength of the specimens increased significantly with the increase of steel plate thickness,with an increase range of 21.74% to 74.71%.The steel plate modification can effectively restrain the longitudinal and transverse deformation of the long column and increase the stiffness.With the increase of eccentricity,the buckling outer drum of specimen steel plate is dominated by the typical failure form of central bending,and the bearing capacity decreases gradually.3.Compared with the long-column specimens of fast-growing poplar modified by CFRP,the axial compressive strength of the specimens increased significantly with the increase of fiber proportion,with an increase range of 52.26% to 72.29%.The adoption of CFRP modification can effectively restrain the longitudinal and transverse deformation of the wooden column,and enhance ductility.With the increase of eccentricity,the specimens gradually changed from strength failure to shear failure of the bonding surface,and the bearing capacity gradually decreased.