Corrosion Behavior Of Steel Embedded In Concrete Treated By Superabsorbent Resin Synthesized In Situ

The problem of concrete structure durability deficiency caused huge economiclosses and resources wasted, which has become the focus of attention.Steel corrosiondamage is one of the most important factors of affecting the concrete structuredurability,which has lead to the concrete structure durability inadequate or failed.It isvital practical significance to take the effective protective measures to improve andenhance the durability of structure to prolong the service life of the structure.The paper uses the polymer precursor solution with initiator and crosslinker intothe concrete cracks or pores to make the precursor copolymerize,which by synthesizingsuper-absorbent resin(super-absorbent resin，for short SAR),through the SAR swollenhydrogel after absorbing water to fill pores of the concrete cracks and cut off thepenetrating path of corrosive medium to delay the embedded steel corrosion of theconcrete.The research contents and results are as follows:（1）The parameter optimization of SAR synthesized in situ.Based on the index ofthe polymerization rate and the water absorption expansion function,as well as thesurface treatment of concrete construction quality and operating time,the test optimizethe material composition parameters of the SAR synthesized in situ is to select themonomer of Acrylic acid and Acryl amide、the redo initiator systems of Tetramethylethylenediamine-Ammonium per sulfate、the cross linking agent of N,N’-methylenedouble acryl amide、the neutralizer of Sodium hydroxide.The test results showthat:When the parameters of c(TEMED):c(APS) is4:1and the parameters ofm(AA):m(AM):m(TEMED-APS):m(MBA):m(NaOH) is4:1:1.94:1:10,theSAR can synthesize in resin for the concrete surface treatment and its reaction rate is controllable.（2）Carbonation and chloride ion penetration of the concrete by using SARsynthesized in situ.Combination the two factors of steel corrosion in reinforcementconcrete,the experiment test the carbonation property and chloride ion penetration ofthe concrete by using SAR synthesized in situ.The test results show that:After theconcrete surface treatment with SAR,it is significance to improve the resistanceperformance of the carbonation and the chloride ion penetration of the concrete andcarbonation can significantly reduce the chloride ion penetration of the concrete.（3）Corrosion behavior of steel embedded in concrete by using SAR synthesizedin situ.The experiment study on the reinforced concrete potential and corrosioncurrent density through the thickness protective layer、carbonization and synthesizedSAR in situ with surface treatment.The test results show that:Increase the thicknessprotective layer of the concrete can retard the rate of steel corrosion；the carbonationinfluence of the steel corrosion is more complex,on the one hand,carbonizationreduce the pH of the reinforced concrete surface medium,which can be accelerated thesteel corrosion；at the meantime,carbonation reduce the chloride ion diffusion of theconcrete,which can be inhibit the corrosion of the reinforced concrete；For thereinforcing steel concrete with thickness protective layer,it is very important to delaythe steel corrosion using SAR to treat the concrete.