Lifetime prediction under dead-load long-term creep test and models analysis of wood-plastic composites for building materials

ABSTRACT Optimal formulation of wood-plastic composites (WPCs) from recycled polypropylene (rPP) and rubberwood flour (RWF) was determined. Mechanical properties and long-term creep behaviour of rPP and WPCs were investigated. This study revealed that an increasing of rubberwood flour content clearly increases the flexural, compressive, and tensile values. The modulus of composite samples linearly increased with an increasing amount of RWF. The creep behaviour test with load levels at 20, 30, and 40% of the ultimate flexural strength were conducted for 1000 h. The deflection of the composites at the same load levels of rPP gave the higher creep behaviour (2.45, 4.65, and 6.68 mm) than that of WPCs (1.53, 2.41, and 3.37 mm), respectively. Six-element for determining Burger model parameters was well fitted with the long-term creep of WPCs, this deflection result was compared to four-element Burger and Power law models. Finally, the master curve could predict lifetime of composite materials.