Comparison of Pavement Slab Stabilization Using Cementitious Grout and Injected Polyurethane Foam: Fid-Bau Portal

Comparison of Pavement Slab Stabilization Using Cementitious Grout and Injected Polyurethane Foam

Vennapusa, Pavana K. R. / Zhang, Yang / White, David J.

This paper reviews the current status of slab stabilization specifications and describes in situ test results and statistical analysis comparing injected polyurethane foam and cementitious grout for a deteriorating jointed concrete pavement supported on an open-graded aggregate subbase. The stabilization was performed to improve support conditions by filling voids, reducing deflections under loading, and improving load transfer efficiency (LTE) near joints and cracks. Falling weight deflectometer (FWD) tests and faulting measurements were obtained before and after stabilization. LTE measurements indicated statistically significant improvement near cracks and joints in both sections. Deflections under loading showed statistically significant improvements only near cracks (and not near joints) in the injected foam section and only near joints (and not near cracks) in the cementitious grout section. Faulting reduced by about 2–5 mm after injected foam stabilization and 1–2 mm after cementitious grout stabilization, while the maximum allowable slab movement during stabilization was 1.3 mm. Although improvements were evident in FWD measurements after both stabilization methods, faulting reductions indicate slab movements that are greater than allowed. This suggests a need for improved process control with vertical movement during the stabilization process, particularly with the injected-foam stabilization method.