Corrosion Resistance, Porosity and Strength of Blended Portland Cement Mortar Containing Rice Husk Ash And Nano-SiO2

Abstract

Nanoparticles (NP) have exceptional physic and chemical properties used in the improvement of the performance or mortar concrete at nanometer scale. Researchers have incorporated nano-SiO2 (nSO), nanoalumina, iron oxide and titanium nanometer, among other NP, in mortars. The use of ashes to improve the properties of mortar has also been studied. However, the study of synergy in the simultaneous use of NP and ashes is scarce, research has focused on improving the physical and mechanic properties of mortar, existing few reports referring to the corrosion resistance. The performance of the simultaneous use of rice husk ash (RHA) and nSO as a replacement for ordinary Portland cement (OPC) in mortar with plastic consistency was evaluated. Studies of compressive strength, total porosity in open pore and accelerated corrosion test with impressed voltage 12.0 V in mortars were made, using replacements of OPC by 10-30% of RHA and 1.00-2.00% of nSO in single and simultaneous use. For the purpose of determining the performance of the OPC replacements on the properties of the mortar, resulting in the most effective use with simultaneous decrease in porosity up to 5.7% and increased compressive strength and corrosion of 7.8% and 51.1%, respectively. The use of superplasticizer facilitated the making of mixtures with RHA and nSO, but affected the physical and chemical properties of hardened mortar. Replacement of OPC by RHA and nSO in simultaneous use in mortars with plastic consistency present the advantage of improving physical and mechanical properties in replacements up to 20% RHA, due to the synergistic effect of RHA-nSO and porosity – compressive strength.