Utilization of Industrial Waste Slag as Aggregate in Concrete Applications by Adopting Taguchi’s Approach for Optimization

Abstract

This paper presents result of an experimental investigation carried out to evaluate effects of replacing aggregates (coarse & fine) with that of Slag (Crystallized & Granular) which is an industrial waste by-product on concrete strength properties by using Taguchi's approach of optimization. Whole study was done in three phases, in the first phase natural coarse aggregate was replaced by crystallized slag coarse aggregate keeping fine aggregate (natural sand) common in all the mixes, in the second phase fine aggregate (natural sand) was replaced by granular slag keeping natural coarse aggregate common in all the mixes and in the third phase both the aggregates were replaced by crystallized & granular aggregates. The study concluded that compressive strength of concrete improved almost all the % replacements of normal crushed coarse aggregate with crystallized slag by 5% to 7%. In case of replacements of fine aggregate and both type of aggregates, the strength improvements were notably noticed at 30% to 50% replacement level. It could also be said that full substitution of slag aggregate with normal crushed coarse aggregate improved the flexure and split tensile strength by 6% to 8% at all replacements and in case of replacing fine aggregate & both the aggregates( Fine & coarse) with slag, the strength improvement was at 30% to 50% replacements. It is evident from the investigation that Taguchi approach for optimization helped in indentifying the factors affecting the final outcomes. Based on the overall observations, it could be recommended that Slag could be effectively utilized as coarse & fine aggregates in all concrete applications.

Feasibility of making Concrete with Iron Slag Scrap as Coarse Aggregate

“…Average of test results of four specimens in each category in respect of compressive and split tensile strength of normal and iron slag scrap concretes at 7 days and 28 days are presented in Table 5. [26] have reported an increase of 5 to 7 per cent in compressive strength of concrete for all percentage replacement of natural coarse aggregates by slag aggregate and in the present investigation an increase of 2.12 per cent greater than that of normal concrete at 75 per cent replacement was obtained. Going by these discussions the compressive strength obtained for iron slag scrap concrete in this investigation is found to be creditable.…”

“…The values obtained for all concretes were consistent. Nadeem and Pofale have reported an increase in split tensile strength by 6% to 8% at all replacements [26].…”

Steel Slag Utilization — Overview in Indian Perspective.

“…Indian cement industry is consuming almost the entire granulated slag produced and can consume up to 70% of the blast furnace slag generated, as less iron content in slag is suitable for the cement manufacturing Based on an experimental work by Nadeem and Pofale (2012), it was concluded that the steel slag could be effectively utilized as a partial replacement for fine aggregate and coarse aggregates in all types of concrete construction purposes. It was also reported that 100% replacement of naturally available crushed coarse aggregates with slag aggregates, enhanced the flexure and split tensile strength by about 6% to 8% in all grades of concrete mixes (Nadeem and Pofale (2012). In an experimental investigation by Maslehuddin (2002), it was found that the concrete with steel slag was having better physical properties than the concrete containing crushed limestone aggregate.…”

Research on the use of Ferro-Chrome slag in civil engineering applications

“…A number of researchers [16][17][18][19] studied the properties of normal and high strength concrete made with FeCr slag as an aggregate. The results indicated that replacement up to 75% of FeCr slag in lieu of fine aggregates improved the strength of concrete compared with conventional concrete.…”