Evaluation of the effects of nanomaterials on durability of engineered cementitious composites exposed to the aggressive environment

Abstract

The present study was aimed to evaluate the effect of micro silica, nano silica and carbon nanotube in the engineered cementitious composites made with polyvinyl alcohol fibers. Accordingly, the compressive strength and the modulus of the samples rupture were studied to evaluate the impact of micro silica, nano silica and carbon nanotube in engineered cementitious composite. In addition, different curing conditions were considered to investigate the durability of the mixes. In this regard, the mechanical properties of the samples cured in sulphuric acid and freeze and thaw cycling were compared to those cured in water. The results indicated that the mechanical properties were reduced upon exposure to acid and freeze and thaw cycling. It was also found that the application of micro silica and nano silica made the mixtures compacted and reduced the permeability. The module of rupture was increased significantly by the addition of carbon nanotube. Moreover, the evaluation of the samples cured in the aggressive environment showed that the role of carbon nanotube was significant in increasing the durability of the mixes. Further, the scanning electron microscopy images showed that the crack width was reduced by the addition of carbon nanotube. It was also revealed from the scanning electron microscopy images that the polyvinyl alcohol fibers were completely interacted and connected to the paste.