Reducing The Acidity of Urmia Lake Water by Non-evaporating Method Sulfate Exteraction, And Its Effect on Reducing Corrosion of Concrete in Causeway Bridge

Abstract

Areas where the soil and groundwater containing large quantities of sulfate and where structures are built in marine environments, must be designed of a kind of concrete that have sufficient resistance about sulfate attacks. Sulfate salts in the solid state are unable to harm the concrete, but when they are in the solution state, can reaction with materials created from the operation of the Cement Hydration i.e. calcium hydroxide, calcium aluminate and silicate hydrate, that these reactions lead to the failure and collapse of concrete. In this study, extraction rate and optimal conditions for utilization of sodium sulfate in Urmia lake water using minimal energy and climate zone and using non-evaporating method has been investigated. Due to the high amounts of sodium sulfate deposits in Iran and also the lack of chemical reaction in the process of processing, consequently easy equipments, tips and technical operating conditions studied in this case is very important. In addition, economic investment was performed on the extraction of sodium sulfate and a plan to create semi-industrial and industrial units for the extraction of sodium sulfate with the lowest energy and money spent has been proposed. Due to abundant amounts of sulfate ion in Urmia lake water, concrete structures of causeway bridge on Shahid Kalantari Highway between Urmia and Tabriz are not safe from corrosion damage resulting from sulfate. In this scheme corrosion causes by sulfate ion and Results of the study was obtained.

Keywords

• reducing corrosion of concrete
• urmia lake causeway
• slfate ion
• non-evaporating method