Experimental evaluation of repairing techniques for holes made in reinforced concrete columns for core tests

Abstract EN

This paper presents the experimental and theoretical studies of reinforced concrete short columns drilled laterally with a hollow of a 50 mm in diameter.

As known, the purpose of the core test is to evaluate the strength of the existing concrete.

Seven square reinforced concrete columns of 150 mm x 150 mm crosssectional area with 520 mm height were cast and tested.

The specimens were reinforced with 8-Ø10 mm having yield strength of 570MPa and concrete compressive strength of 31.0MPa.

Five different strengthening techniques were adopted to drilled columns.

The results indicated that the combination method of strengthening like filling the drilled hole with cement base grout and wrapping it with CFRP sheets lead to an increase in load carrying capacity up to 19.5% and 50.5% relative to solid and drilled columns, respectively.

While strengthening with steel pipe and wrapping by CFRP sheets enhanced the load capacity by 13.6% and 43.0%, respectively when compared to solid and drilled column specimens.

Briefly, the strengthening process of the drilled column can lead to load carrying capacity even more than that of the solid column.

The modified ACI Code equations gave conservative results (PExp./PTheor ≥ 1.0) for tested strengthened specimens of this study, and they showed good agreement when applied to the available drilled columns from literature.