Influence of Steel Slag Type on Concrete Shrinkage

Abstract

Building construction and building operations have a massive direct and indirect effect on the environment. Cement-based materials will remain essential to supply the growth of our built environment. Without preventive measures, this necessary demand in cement production will imply a substantial increase in CO2 generation. Reductions in global CO2 emissions due to cement consumption may be achieved by improvements on two main areas: increased use of low CO2 supplementary cementitious materials and a more efficient use of Portland cement clinker in mortars and concretes. The use of ground granulated blast furnace slag in concrete, as cement constituent or as latent hydraulic binder, is a current practice, but information of concrete with ladle furnace slag is more limited. Specific knowledge of the behavior of mixtures with steel slag in relation to certain properties needs to be improved. This paper presents the results of the shrinkage (total and autogenous) of five concrete mixtures, produced with different percentages of two different slags in substitution of cement. The results show that shrinkage of concrete with the two different slags diverges. These different characteristics of the two materials suggest that their use in combination can be useful in optimizing the performance of concrete.

Development in Sustainable Concrete with the Replacement of Fume Dust and Slag from the Steel Industry

“…This loss may occur because the reaction of the slag increases the chemical shrinkage of calcium silicate hydrate (C-H-S), which leads to an increase in microcracks and reduced resistance [ 35 , 36 ]. It was observed that in AFD at 28 days, the increased strength was maintained at a rate of 12.4% and in FFD at 21.7% These increases may be due to the fineness of the material and the absorption of water by the residue [ 10 , 20 , 21 ] hydrating the cement and reducing the air content in the interstitial spaces. As it has practically the same fineness as the cement, the internal reaction produced is favourable to the mixture.…”

“…Regarding the percentage of substitution in cement, in previous studies with different residues from steel mills [ 10 , 24 , 25 , 26 ], tests were carried out with substitution percentages ranging from 5% to 35%, and the most representative values were found between 25% and 27%. Therefore, in order to homogenise the process, 25% was chosen, since it was the average of the best results of all tests carried out.…”

“…On the other hand, even though the slag is not toxic, it must also be taken to landfills due to its high basic composition [ 7 ]. In addition, stabilising this type of material before taking it to a landfill has been studied [ 8 , 9 , 10 ].…”

Influence of Recycled Cement Paste Powder on Early-Age Plastic Shrinkage and Cracking of Cement-Based Materials

“…Bella et al [14] concluded that environmental wind potentially reduces the compressive strength by increasing evaporation compared with the ambient temperature, and that plastic shrinkage could be avoided by taking precautions in the curing phase by using adequate and efficient curing procedures, such as plastic sheets or curing compound, coupled with windbreaks or cooling of the concrete ingredients. Moreover, various fibers were tested and applied for shrinkage reduction [15]. Using fibers is a common method for reducing plastic shrinkage in concrete [16].…”

Innovative Structural Applications of High Performance Concrete Materials in Sustainable Construction

“…Similarly, the partial replacement of Ordinary Portland Cement (OPC), which is notoriously the most environmentally harmful among concrete constituents, with other Supplementary Cementitious Materials (SCMs) or Alternative Binders (ABs) should undergo careful research work intended at assessing the actual performance of the resulting cementitious composites. In this respect, promising results have been obtained by considering several SCMs or ABs, such as Municipal Solid Waste Incinerator Bottom Ash [4], Belitic Calcium Sulfoaluminate Cement [5] or Steel Slag [6], the latter consisting of either ground granulated blast furnace slag (GGBFS) or unprocessed ladle furnace slag (LFS).…”