Research On Connection Method Of Phosphogypsum Panel And Light Wood Skeleton

Guizhou Province actively encourages research and development of the comprehensive utilization of phosphogypsum solid waste to produce building wall materials.Applying phosphogypsum to light wood structure houses is another way to promote the large-scale and resource-based comprehensive utilization of phosphogypsum in the field of building materials.The original phosphogypsum material from Wengfu phosphate mine in Guizhou Province was selected and directly prepared into phosphogypsum board without calcination.The self-made phosphogypsum panel was taken as the research object to study the connection mode of phosphogypsum board,paper-based phosphogypsum board and Ochroma skeleton nail.Selecting different nail margins of different types of plates and the direction of Timber framing texture under load,the monotonic load shear tests are carried out on nail joints,various influencing factors and laws of the mechanical properties of nail connection of different panels are analyzed,and mechanical models of the connection of phosphogypsum board and paper-based phosphogypsum board with nails are put forward.The finite element software ABAQUS is used to establish the nail connection analysis.By comparing the analysis results with the test results,the reliability of the nail connection mechanical model proposed in this paper in finite element analysis is verified.The results show that:1)Through the experiments of phosphogypsum board and paper-based phosphogypsum board,the influencing factors of mechanical properties of the board are studied.The study found that the moisture content of phosphogypsum material has a great influence on the mechanical properties of the board,and drying treatment is required before preparing phosphogypsum board.The flexural strength of paper phosphogypsum test block is 35.11% higher than that of phosphogypsum test block,and the compressive strength and water absorption have no obvious change compared with phosphogypsum board.2)The testing results show that the failure modes of the three panel materials and the wood skeleton nails are basically the same,which are the fracture failure of the panel at the joint of the nails.Among the pattern of the failure,the phosphogypsum board is a typical brittle failure.Due to the effect of paper fibers,the thistle board and the paper-based phosphogypsum board have a significant increase in ultimate load carrying capacity and ductility.During the failure process of the gypsum plasterboard and the paper-based phosphogypsum board specimen,the situation that the screw is immersed in the plate,the nail is bent,and the adhesive layer is cracked in the panel occurs.3)According to the testing results,the mechanical model by nails' connection of phosphogypsum board and paperr-based phosphogypsum board is proposed.Therefor,the bearing capacity and displacement along the grain direction in Timber framing increase with the increase of nail margin.The connection performance is optimal when the nail margin is 25 mm.The minimum nail margin of 25 mm should be ensured in engineering application.4)The finite element software analysis results show that the nonlinear spring model is more consistent with the actual nail connection failure results due to the mechanical model obtained from the experiment.It is recommended to adopt the nonlinear spring model in the overall analysis model.