Triaxial Mechanical Properties and Mechanism of Waterborne Polyurethane-Reinforced Road Demolition Waste as Road Bases

Abstract

The recycling and reuse of construction waste have not only effectively protected natural resources but also promoted the sustainable development of the environment. Therefore, in this article, waterborne polyurethane (WPU) as a promising new polymer reinforcement material was proposed to reinforce the road demolition waste (RDW), and the mechanical performance of WPU-reinforced RDW (named PURD) was investigated using triaxial unconsolidated and undrained shear (UU) and Scanning Electron Microscope (SEM) tests. The results showed that under the same curing time and confining pressure, the shear strength of PURD increased with the increase in WPU content. When the WPU content was 6%, the WPU presented the best reinforcement effect on RA. The failure strain of PURD increased with the increase in confining pressure, but increased first and then reduced with the increase in WPU content. The specimens with 5% WPU content showed the best ductility. At the curing time of 7 and 28 days, the internal friction angle and cohesion of PURD increased with the increase in WPU content, and they reached a maximum when the WPU content was 6%. The internal friction angle barely budged, but the cohesion increased obviously. The enhancement effect of WPU was attributed to the spatial reticular membrane structure produced by wrapping and bonding particles with the WPU film. Microscopic analysis showed that with the increase in WPU content, the internal pore and crack size of PURD gradually decreased. As the WPU content increased, the WPU film became increasingly thicker, which increased the adhesion between WPU and RA particles and made the structure of PURD become increasingly denser.

Shear Behavior of Recycled Fine Aggregate Reinforced by Nano-MgO Modified Cement

“…After removing the asphalt layer on the abandoned road subgrade, the aggregate at the bottom of the subgrade was crushed and screened to obtain recycled fine aggregate with a particle size of less than 4.75 mm. Laboratory geotechnical tests of recycled fine aggregates were carried out according to “Test Methods of Materials Stabilized with Inorganic Binders for Highway Engineering” (JTG E51-2009) [ 19 ], and their basic physical properties were measured as shown in Table 1 , which was obtained from the research of Lv et al [ 20 ]. The main chemical components of recycled fine aggregate are SiO 2 and CaCO 3 .…”

A State-of-the-Art Review of Organic Polymer Modifiers for Slope Eco-Engineering

“…PU has stable reaction products, good adhesion, heat resistance, and elastoplasticity when used to reinforce and stabilize the soil. It performs well in slope construction because its short gelation time can reduce the adverse effects of rainfall [69]. The reactive isocyanate groups (-NCO) of PU molecules react with the capillary water in soil particles, forming physical and chemical bonds between PU molecules and soil particles.…”

Polymeric Composites in Road and Bridge Engineering: Characterization, Production and Application

“…Jiang et al used PP fiber and cement to modify iron-ore tailing in road engineering as an effective reuse strategy [ 15 ]. Lv et al adopted waterborne polyurethane (WPU) to reinforce the road demolition waste as a promising new polymer reinforcement material [ 16 ].…”