Use of Nanomaterials for Concrete Pipe Protection

摘要

This paper describes an innovative method for mitigating microbial inducedrncorrosion (MIC) in concrete sewer pipes by driving nano-particles containing anrnantimicrobial agent into the wall of the steel-reinforced cementitious pipe usingrnelectrokinetics, an electrical deposition method. Electrokinetic coating involvesrnthe application of a weak electric field between the pipe reinforcement and arnproperly charged solution of nanoparticles. The electrical potential differencerndrives the nano-particles in the solution into the hardened concrete paste via itsrnpore structure, simultaneously transporting the antimicrobial agent(s) into thernpores. This new method of coating creates a mechanical anchorage between therncoating liquid and the host matrix, which has inherent advantage over traditionalrnbrush or spray-on coating operations. The paper provides a brief overview ofrnrecent advances in spray-on coating and lining methods for protecting concreternpipe used in wastewater conveyance systems. Thereafter, a brief description ofrnelectrokinetics is provided. Preliminary results of an experimental testing programrninvolving electro-kinetically coating of 35 mock concrete pipe specimens usingrncuprous oxide, a heavy metal oxide known the have a toxic effect on sulfaternreducing bacteria (SRB), are presented. The preliminary testing program focusedrnon examining the effectiveness of using electrokinetics for the treatment of newrnpipes, partially deteriorated pipes and pipes that exhibited moderate-to-severerndeterioration due to sulfuric acid attack. The design of the experiment and thernexecution of the electrokinetic coating process are also described. The resultsrnsuggest that the approach could potentially serves as an effective method forrncoating of new and partially deteriorated reinforced concrete pipes.