Experimental Research On Durability Of Grout Sleeve Reinforcement Joint

Taking full grouting sleeve connection steel bar as the research object,the influence of external environment,age,accelerated corrosion mode,steel bar size and grouting material type on durability is explored,and the microscopic corrosion law of reinforced concrete interface area is explored.In order to improve the durability of grouting sleeve steel connection and provide experimental and theoretical reference for standard revision.1)111 simulated specimens,including 48 connection specimens,18 accelerated cathode specimens and 45 chloride ion environment specimens.Parameters include grouting material type(silicate,sulphoaluminate,composite),connection mode(positive,negative),accelerated cathode mode(simulated pore solution,calcium hydroxide),chloride ion concentration(1.5%,1.0%,0.5%,0%),etc.Through the grouting material p H value,corrosion potential,steel bar mass loss rate shows that: steel bar connection positive electrode is less than-350 mv,more accelerated corrosion.When the steel bar is connected to the positive electrode,the corrosion rate of silicate specimen is the lowest at 7d and 28 d,which are 0.75% and 0.11%,respectively,and that of sulphoaluminate specimen is the highest,which are 0.52% and 0.57%.And the corrosion rate of steel bar connected with negative pole is less than that of steel bar connected with positive pole at the same age,which confirms the above conclusion.2)42 mechanical and microscopic specimens,24 mechanical specimens,18 microscopic specimens.Parameters are grouting material type(silicon,sulfur aluminum),specifications(12mm,20mm),age(28d,60 d,90d),etc.The p H value,corrosion potential,mass loss rate,corrosion electron microscope,energy spectrum and tensile results show that the p H value of sulphoaluminate grouting material is low.The absolute value of corrosion potential of sulphoaluminate corrosion specimen is high,and the mass loss rate is high.The distribution of rust layer on the reinforcement of silicate grouting material is more uniform.Electric environment,single tensile results are steel bar fracture,no pullout,sleeve slip phenomenon.Figure 88;Table 20;Reference 58...