An experimental study on the strength and corrosion of blended cement concrete exposed to seawater in an arid region

P. M. Hoby ； A. S. Santhi ； G. Mohan Ganesh

《淡江理工學刊》 25卷6期 (2022/12) Pp. 1227-1237

https://doi.org/10.6180/jase.202212_25(6).0018

摘要

Exposure to the marine environment causes a gradual diminution in the strength and resistance to corrosion of a reinforced concrete structure. Studies about the behavior of blended concrete exposed to marine environments in arid regions are less in numbers and in-depth analyses are not widely available. This research aimed to study the structural behavior and corrosion resistance of blended cement concrete exposed to seawater in an arid region (Muscat, Oman) for one year. Four mixes namely, control mix (100% cement), two binary blended mixes (90% cement+10% silica fume and 60% cement+40% fly ash) and one ternary mix (50% cement+40% fly ash+10% silica fume) were used for tests. Each sample for the experiment was prepared to attribute 25 mm and 50 mm covers to the reinforcement. The samples were cured in normal water and seawater under the worst condition of alternate wet and dry, in the natural weather of the Muscat region for up to one year. The mechanical properties were assessed and the corrosion behavior was analyzed by an accelerated corrosion test. Scanning Electron Microscopy (SEM) was done on the samples for microstructure analysis. The test results indicate that the ternary blended concrete mix gives the maximum compressive split tensile strength and minimum corrosion. The results of SEM analysis were in concordant with the experimental results. Using regression analysis, an empirical equation was formulated to predict the weight loss of rebar in an accelerated corrosion test. The equation has been validated using the experimental data from other authors.

關鍵字

Blended concrete ； fly ash ； silica fume ； binary ； ternary ； scanning electron microscopy ； accelerated corrosion test