Nanotechnology Applied to Chemical Soil Stabilization

摘要

The chemical stabilization of a soil is dependent on a wide range of parameters, being the most important ones associated to the soil properties and cementitious materials. The mechanical behavior of a soil can be improved with addition of nanoparticles, which are not a cementitious material but once introduced in a soil they are expected to reduce the interparticles' spacing and nanoreinforce it. This will promote the construction of a stronger and stiffer soil skeleton matrix together with the cementitious materials. However, to maximize the benefits of the nanoparticles added to a stabilized soil it is crucial to overcome the problems related with particle agglomeration. Thus, it was defined a screening strategy which comprises the characterization of the nanoparticles, the definition of the aqueous medium with surfactant addition, the characterization of the surfactant and the application of energy to promote the particles' dispersion. The quality of the suspension, in terms of particles' dispersion, was evaluated trough the analysis of the particle size distribution given by dynamic light scattering (DLS). After, a series of performance tests with cement Portland and nanoparticles were conducted. The results from the unconfined compressive strength (UCS) tests have shown the high potential of adding multiwall carbon nanotubes to a chemically stabilized soil. The results have also pointed out the importance of the nanoparticles dispersion process.