Behavior of Corrosion-Repaired Concrete Beams Reinforced by Epoxy Mortar

The performance of concrete beams repaired with epoxy mortar was investigated by constructing twelve beam specimens.All the beam specimens were subjected to a constant current for accelerated corrosion.Six specimens were corroded without subsequent reparation as a control group,and the other six beam specimens were corroded and repaired utilizing epoxy mortar.All specimens were tested to failure.During test process,we focused on the failure pattern of beam specimens,structural cracks,mid-deflections,bearing capacity,and probed into the influence of corrosion degree and repair of epoxy mortar on the performance of beam specimens.It was observed that corrosion-repaired beams in the loading test were in a bending failure pattern.It is obvious that cracking loads and bending stiffness of repaired beams and corrosion-repaired beams were larger than those of unrepaired beams and secondly-corroded beams.When the mass loss of main steel bars was smaller than 10%,the bearing capacity of the repaired beams was similar to that of the unrepaired beams.When the mass loss of main steel bars was larger than 10%,the bearing capacity of the repaired beams increased significantly compared with that of the unrepaired beams.

Performance of Epoxy-Repaired Corroded Reinforced Concrete Beams

Reinforcement corrosion has a serious impact on the durability and safety of reinforced concrete structures.Six reinforced concrete(RC)beam specimens are constructed.After beam specimens are subjected to accelerated corrosion with the constant current,beam specimens are repaired with epoxy mortar and the flexural test of beams is investigated.Then the behaviors of repaired corroded reinforced concrete beams are evaluated.The experimental results show that cracking and ultimate loads of corroded RC beams are enhanced after being repaired.And the strain distributions measured across sections of beam specimens still obey the assumption of plane section.After being repaired,the number of cracks decreases and the crack spacing increases.

Experimental Study of Hygrothermal and Ultraviolet Aging on the Flexural Performance of Epoxy Polymer Mortar

This paper studies the effects of hygrothermal environment at different temperatures and ultraviolet(UV)radiation on the bending properties of epoxy polymer mortar(EPM).The microstructure changes of EPM during aging were studied by scanning electron microscopy,and the bending properties of EPM were predicted by the Arrhenius law.The results showed that the bending properties of EPM were greatly affected by the temperature in the hygrothermal aging,but not evidently affected by ultraviolet radiation in UV aging.The prediction of Arrhenius model shows that the EPM will steadily retain 92.8%,89.1%and 79.4%of the original flexural strength after long-term hygrothermal aging at 40∘C,60∘C and 80∘C,respectively.