Production and Compression Strength of Mortars Containing Unprocessed Waste Powdered Steel Slag

Abstract

This paper deals with the production of mortars prepared using a commercial CEMIIB-S 42.5N cement, a natural aggregate, steelmaking slag, a superplasticizer and water. The as-received unprocessed steel slag was milled by a hammer mill and then sieved to obtain batches with different maximum particle size. Each batch was used, together with the other components, in the production of mortars which were tested, by compression and water absorption, after different aging times in order to evaluate their long term stability. Several slag-free samples were also prepared as reference materials. All mortars were prepared with fixed aggregate/cement ratio (6/1), superplasticizer/cement ratio (s/c) and water/cement ratio (w/c). It has been demonstrated that an adequate protocol for the preparation and the use of slag containing particles with 2500 µm maximum size lead to the production of materials with mechanical properties suitable for civil engineering applications after aging for 28, 90 and 180 days. However, samples containing slag particles with size equal or greater than 1000 µm display a decay of mechanical properties after longer aging in water or after accelerated aging.

Possible Recycling of End-of-Life Dolomite Refractories by the Production of Geopolymer-Based Composites: Experimental Investigation

“…In fact, literature clearly reports that the presence of MgO or CaO into a geopolymeric network could have beneficial effects on the properties of the hardened materials because their reactions limit material's shrinkage and refine the pore size distribution within the geopolymeric paste provided that the components used for materials preparation are in the form of fine powders [41][42][43][44][45][46][47][48][49]. However, it is reasonably expected that the presence of such compounds into coarse particles, being cause of uncontrolled instabilities, could generate fractures and chipping in hardened materials as it has been observed also in cement-based mortars containing coarse steel slag and therefore coarse CaO-and MgOcontaining particles [32][33][34].…”

“…The above phenomena could be amplified when CaO-and MgO-containing compounds are not in the form of fine powders, but their feature consists of granulated products. As a consequence, their use in the production of cement-based materials or in the manufacturing of roads or streets must be limited to very little quantities or require severe treatments before recycling as it has been clearly demonstrated by several research papers [26][27][28][29][30][31][32][33][34].…”

Classification of BOF Slag by Data Mining Techniques According to Chemical Composition

“…1-3 Cu 0.03 Mo 0.08 As <1 ppm Cd <0.5 ppm B 0.17 The main components of this type of slag are Fe, CaO, and SiO2.. The lime-free content limits the recyclability of this material in roads, cement, and other applications, where the expansibility of the final product is a critical parameter [18,19].…”

“…Due to the vast research performed with the aim to valorize slag, it is interesting to obtain a relationship between potential applications and slag clusters [18,19,29,30]. If this is performed for every possible application, a better valorization of each slag cluster can be obtained.…”

Sustainable Use of Steel Industry Slag (SIS) for Concrete Production: A State Art of Review

“…Recycling of SS, however, could be handy as long as the materials provided have good durability and retain properties in line with standards specifications after long aging [3]. The steel slag used in cement and concrete production as aggregate or as additional cementing materials has a significant positive impact on environment due to its long-term strength and durability [4] [5]. For the sustainable development, large-scale utilization of SS is crucial because of its massive production, which will create environmental hazards if it is dumped directly.…”