Microstructural study and surface properties of concrete pavements containing nanoparticles

Abstract

This investigation focused on the effect of nanoparticles on microstructural surface characteristics, abrasion, and skid resistance of concrete pavements. Firstly, the percentage of optimal replacement of nanoparticles was determined. In the second part, the nano-modified concrete similar to mortars in terms of water-to-cement and sand-to-cement ratio were made to study the abrasion resistance and British pendulum number (BPN) as skid resistance property. Mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were applied to accurately evaluate the microstructural properties. Concerning concrete containing different nanoparticles, nano-montmorillonite yielded the most considerable improvement in abrasion resistance (about 23%). By examining the MIP results, a good correlation was observed between the volume of the large pores plus the average pore size and the volume reduction in the abrasion test. By comparing the effect of nanoparticles on improving the skid resistance under wet and dry conditions, it was found that the samples containing nanoparticles in dry conditions generated more significant improvements (about 20%) compared with the wet conditions (about 7%). The results of the AFM test revealed that improvement in samples containing nanoparticles was because of increased surface roughness and enhanced surface adhesion due to Van Der Waals forces.