Soy-based polyurethane spray foam insulations for light weight wall panels and their performances under monotonic and static cyclic shear forces

Abstract

This work was dedicated to the investigation of the strengthening effects of soy-based rigid polyurethane (PU) foam cores, neat and composite foams containing wood fiber, on the performance of small-scale wooden wall panels under monotonic and static cyclic shear loads. Adding wood fiber resulted in a reduction in the density (23%) and compressive strength (63%) of the foam while specific tensile modulus, ratio of tensile modulus to density of foam, increased about 39%. Both monotonic and static cyclic shear tests showed that inclusion of the composite foam core increased the maximum strength of panels significantly. Panels containing composite foam cores had an average shear strength of 12.0kN compared to 10.7kN and 8.0kN for panels with neat foam and empty panels, respectively. The results of this research demonstrated for the first time that, in addition to their thermal insulation capabilities, soy-based rigid PU foams significantly contribute to the shear strength of wooden wall panels. This characteristic is important especially in the construction of residential and low-rise commercial buildings.