Enhancing wood-plastic composites for high-performance structural applications

Abstract

To address the limitations of traditional wood-plastic composites (WPC), including low strength, susceptibility to creep, brittle fracture, and poor dimensional stability, and to fill the gap in building load-bearing structures, we have developed a novel structural WPC (S-WPC) with high strength, high ductility, high creep resistance, and high dimensional stability. S-WPC was fabricated utilizing self-developed co-extrusion molding equipment and incorporating high-strength, high-ductility GFRP bolts as reinforcing elements. The S-WPC with 5 bolts exhibited substantial improvements compared to the control WPC. Specifically, there was a 441.7 % increase in flexural strength, a 46.5 % increase in modulus, and an outstanding 1168.0 % improvement in ductility. Additionally, flexural deflection reached 14.2 cm, while the work of rupture showed a remarkable improvement of 4946.0 %. Furthermore, the linear expansion coefficient and 1000-h creep strain were reduced by 85.4 % and 68.6 %, respectively. The integration of the bolt's threaded structure with nuts allows for secure attachment of WPC to load-bearing structures such as floor slabs and shear walls. The flexural performance of S-WPC under fixed-end constraints was evaluated using a custom steel frame structure, revealing a substantial enhancement over traditional WPC. The flexural strength of S-WPC reached 422 MPa, a 2055 % increase compared to the control WPC, surpassing the performance of wood-based panels, structural bamboo scrimber, and other conventional building materials. Finite element simulation was employed to optimize the structure, explore optimal structural design, and assess theoretical load-bearing capacity. S-WPC shows immense potential for replacing conventional materials such as reinforced concrete and for use in the development of low-density, green prefabricated buildings.