AGING EFFECT ON BOND STRENGTH IN COMPOSITE SECTIONS

Experimental results of previous research showed that the bond strength between structural steel shapes and concrete in composite sections at the age of one year is approximately 30% of that at the, age of three weeks. A literature survey reveals that no research has been conducted to investigate bond strength in composite construction at ages over one year. This paper reports the results of tests conducted on 15 battened composite specimens to investigate bond strength between steel and concrete at the age of five years. Test results of this investigation show that the bond strength at the age of five years is more than twice that at the age of 360 days. The reduction in bond strength in specimens of five years of age is significantly less than that in specimens 360 days old, when compared with results of 21-day-old ones.