Evaluation of the use of steel slag in concrete

Abstract

The increasing demand for road construction led researchers to search for an economical and ecological pavement design. To achieve this goal in concrete pavement, various substitutes were found to be replaced with natural aggregates of concrete. Among those is steel slag which is produced as a waste material in the steel industry and has a negative impact on environment when disposed. In this study, the effect of utilizing air-cooled steel slag from Zob-Ahan steel production factory in concrete is evaluated. General observations are carried out according to ASTM D 5106 in order to consider suitability of steel slag replaced with natural aggregates of concrete. Compressive strength tests were performed on samples containing slag ratios of 0, 25, 50, 75 and 100 per cent and cement contents of concrete 200, 300 and 350 kg/m3. According to the results, compressive strength improves with the increase in steel slag ratio up to 25 per cent but increasing the steel slag ratio above 25 per cent decreases compressive strength. Concrete mixes with higher slag ratios meeting the ACI 325.10R-99 standard with different cement contents were tested for flexural strength. The results indicated that the higher the slag ratio, the higher the flexural strength.