Lightweight Sidewalk with Recycled Woodchip and Low-VOC Urethane Resin

Abstract

The conventional resin used for woodchip sidewalks contains a significant amount of volatile organic compounds (VOCs), and the potential of air pollution could be high due to the release of VOC materials during the sidewalk’s construction. In this paper, a brand new polyurethane resin binder with low VOC levels was developed and used as a binder. Laboratory tests for its flammability, elasticity, permeability, and tensile strength, and as well as tests for freeze and thaw, skid resistance, and field construction, were conducted. The nonvolatile fraction of the newly synthesized resin was measured at approximately 98.8%, whereas that of the previous resin was approximately 93.5%. The measured tensile strength ratios of the woodchip mixtures satisfied guidelines for freeze and thaw. The measured critical heat flux at extinguishment (CFE) satisfied Class C of European flame standards. The permeability remained the same with curing time after field construction. The elasticity of the woodchip pavement increased as time passed due to the hardening of the urethane resin. The woodchip pavement using Resins 2 and 3 satisfied the standard specification of skid resistance.