Polymer Nanocomposites for Infrastructure Rehabilitation

Abstract

Polymer matrix composites (PMCs) are becoming increasingly important in the structural repair and rehabilitation of damaged infrastructure – from pipelines to buildings to bridges. For example, composite overwraps are used to repair corroded steel pipelines because the repair can be completed in a relatively short amount of time and the fluid transmission in the piping system can remain undisrupted while the repair is being made. Often in these applications, a primer and filler adhesive is used to fill defects in the substrate so that load can be adequately transferred to the continuous fiber composite. In this work we discuss various nano-scale reinforcements such as fumed silica, alumina, nanoclay, and carbon nanotubes as additives to this filler adhesive in order to improve mechanical properties and to tailor the thermal expansion of the composite to match the underlying substrate being repaired. The thermal expansion mismatch is especially important in applications where temperature fluctuations are present. We highlight our results from rheology, thermal expansion, and dynamic mechanical analysis testing of nanosilica/cyanate ester composites and show that the incorporation of the nano-scale fillers can result in improvement of the thermo-mechanical behavior of the composites.