Relationship between alumina and chloride content on their physical and corrosion resistance properties of concrete

الملخص EN

The relationship between alumina and chloride content on the physical and corrosion resistance properties of OPC concrete was studied.

Friedel’s salt was formed in situ in OPC concrete by the addition of various percentages of alumina (1 % to 15 %) along with 1 % CaCl2.

The compressive strength data revealed that the addition of Al2O3 increased the early strength of concrete.

The Friedel’s salt formation up to 5% Al2O3 showed maximum compressive strength.

The Rapid Chloride Ion Permeability Test (RCPT) revealed that the quantity of electrical charge passed for OPC concrete at 5% Al2O3 showed a 50 % reduction in coulombs.

The 12V impressed voltage test indicated a gradual increase in anodic current flow and delayed time taken for initial crack up to 5 % Al2O3 addition.

Potential vs.

time data from microcell corrosion studies maintained the passivity of steel embedded in OPC concrete up to 5 % Al2O3 throughout the exposure period of 12 months.

Correspondingly, the macrocell current was also considerably reduced (50 %) in OPC concrete at the 5 % Al2O3 level.

Scanning electron micrographs revealed a denser formation of Friedel’s salt at the 5 % Al2O3 level.

The XRD pattern at the 5 % Al2O3 level also confirmed the existence of a greater amount of Friedel’s salt.

The optimum percentage of alumina for the formation of Friedel’s salt in OPC concrete with improved properties was found to be 5 %.