Acid Corrosion of Plain and Reinforced Concrete Sewage Systems

Abstract

The infrastructure of concrete sewage systems is affected notably by biogenic sulfuric acid attack, which causes rapid deterioration of each of its components. To provide a better understanding of this mechanism of damage, this paper reports on research carried out to study the response of the cementitious concrete matrix and the reinforcement steel under the attack of sulfuric acid. Concrete industrial pipes were cast using ordinary portland cement and pulverized fly ash, and specimens obtained from the mixes were left for several cycles in a solution of sulfuric acid at different pH. Experiments were carried out to assess the loss of weight and the electrical corrosion potential. Results showed that sulfuric acid attack can be considered a surface phenomenon, in which the acid attack destroys the cover of concrete before it reaches the reinforcement.