Experimental Study on Permeability and Mechanical Properties of Nanomodified Porous Concrete

Abstract

Porosity of porous concrete is an important parameter used for both mechanical properties of pavement and environmental design. Nano-particles have received increasing attention and have been used in various fields such as concrete to develop novel materials with interesting functions, all because of dedicated physical and chemical properties of nanoparticles. The authors describe new findings of an experimental work on mechanical properties and permeability of porous concrete containing nano-silicon dioxide. Plain porous concrete and porous concrete containing micro-silicon dioxide have been studied as control materials. Twenty-eight-day results showed higher compressive and flexural strengths for porous concrete containing nano-silicon dioxide compared with those of plain porous concrete with the same water–cement ratio. It was demonstrated that nano-silicon dioxide was more effective than micro-silicon dioxide in enhancing porous concrete flexural strength. Samples with 5% nano-silicon dioxide by weight of binder presented the highest mechanical properties, in which the flexural and compressive strength of porous concrete were enhanced by 56% and 48%, respectively. From experimental study of the permeability behavior of porous concrete containing nano- and micro-silicon dioxide, it appeared that nano-silicon dioxide and micro-silicon dioxide could both reduce water penetration through porous concrete; however, micro-silicon dioxide was found more effective for equal nanoparticles and material voids.