İsa Yüksel

Use of granulated blast-furnace slag in concrete as fine aggregate

Experimental studies were performed on the use of non-ground-granulated blast-furnace slag as an aggregate in concrete. Using industrial by-products can help reduce greenhouse gas emission, and can be more economical than normal Portland cement concrete. While grinding the slag puts an additional burden of cost into production, using them as a partial fine aggregate does not increase the cost. This paper performed studies on compressive and flexural strength, water absorption, unit weight, durability of high temperatures, freezing and thawing, and rapid chloride permeability tests establish that non-ground-granulated blast-furnace slag can used as a fine aggregate in concrete.

Properties of Concrete Containing Nonground Ash and Slag As Fine Aggregate

The possibility of using granulated blast-furnace slag (GBFS), furnace bottom ash (FBA), and their combination as fine aggregates in concrete was studied by performing experiments. These materials were used without applying any preprocesses such as sieving and grinding. The compressive, flexural, and split tensile strengths of concretes with natural sand replaced with GBFS, FBA, and GBFS plus FBA at 10, 20, 30, 40, and 50% were examined at a fixed water-cement ratio (w/c). The percentages represent the replacement percentage of fine aggregate by GBFS, FBA, or their combination and were evaluated depending on weight basis. Also, microstructure and water absorption capacity of concrete were researched. Test results showed that concrete strength decreases with increasing replacement ratio with respect to reference concrete. In addition, FBA decreases the strength of concrete more than GBFS. In particular, the strength of concrete was detrimentally affected when the replacement ratio was beyond 40%. The microstructure studies showed that different pore structures were formed in the concrete depending on the replacement material, that is, GBFS or FBA. It is concluded that the main reason for the strength reduction in new concrete is the formation of a porous concrete structure. Moreover, an increase trend in water absorption capacity was observed for both replacement materials.

Effects of bottom ash and granulated blast furnace slag as fine aggregate on abrasion resistance of concrete

Abstract Abrasion resistance is one of the most important durability properties of concrete. Especially, highway, airport and industrial floor pavements should be resistant to abrasion. Recently, many research studies have been carried out on the utilization of industrial by-products in concrete. Granulated blast-furnace slag (GBFS) and bottom ash (BA) are two of these by-products. BA is not generally utilized in concrete and has a limited usage. It is mostly dumped, leading to additional costs and environmental problems. On the other hand, both GBFS and BA have potential for concrete production to provide sustainability. They can substitute fine aggregate thanks to their positive effects on concrete durability. Therefore, the aim of this study was to investigate the abrasion resistance of concretes produced with GBFS and BA substituting fine aggregate. Three different concrete series were produced by replacing fine aggregate with GBFS, BA and both of them by mixing them at equal ratios. The replacement ratios of by-products were 10%, 20%, 30%, 40% and 50% by volume. Compressive strength and Bohme abrasion tests were conducted on series. Results were compared to each other. It can be said that abrasion resistance can be improved by these by-products.