Granulated Blast Furnace Slag Sand Research Articles

Crack Resistance of Concrete Using Granulated BlastFurnace Slag Sand under Flexural Stress

AbstractGranulated blast‐furnace slag sand (BFS) has the potential to be used as an alternative to fine aggregates in concrete production. The interface between the cement paste and the aggregate in concrete is densified when BFS is used, due to the hydrates that are generated by its latent hydraulicity. This fact suggests that the crack resistance of concrete, which is closely related to the conditions at the aggregate interface, would be enhanced by the use of BFS. The fracture energy (GF) of concrete under flexural stress is here measured to evaluate the crack resistance of concrete made using BFS. BFS samples from three different steel mills in Japan are used as the fine aggregates for concrete production, and mountain sand is used as a natural sand for comparison. Compressive strength, static modulus of elasticity, and fracture energy tests are conducted at the material ages of 28 and 91 days. The GF of the BFS concretes increase with increasing compressive strength; on the other hand, the GF of the concrete made using mountain sand decrease. Thus, it is concluded that BFS concrete has superior properties to concrete made using natural sand in terms of the crack resistance under flexural stress, especially in high‐strength regions for large material ages.

Experimental investigation on strength, durability and micro structural characteristics of slag based concrete

In this study, experimental investigations are conducted using 100 percent Portland Slag Cement and Processed Granulated Blast Furnace Slag sand (PGBFS, iron slag) with 100 percent and partial or full replacement of Natural Coarse Aggregates (NCA) with Ladle Slag Aggregates (LSA) with 0, 20, 40, 60, 80, and 100 percent variations. All of the materials used in the inquiry are manufactured by Jindal Steel Works' Bellary factory in India. It has been shown that aggregates containing 20 percent Ladle slag provide the highest strength. Again, 5 percent variation strength tests are conducted, and it is determined that maximum strength is attained with 20 percent variance. The XRD examination demonstrates that the intermolecular bonding between hardened aggregate and cementitious paste is mostly comprised of silicates with a high degree of crystalline order. Due to the fact that the XRD test pattern is mostly composed of quartz aligned with alite and belite, the spaces between the substrate have been minimized to a minimal extent, which may contribute to the concrete's excellent endurance. For 20 percent variance, the tests of durability are modest, as shown by the durability test. The SEM images show porous structures which suggest a limited formation of C-S-H, gel and a correlation between them. The calcium hydroxide generated during cement hydration could be the result of interaction with the reactive amorphous silica present in slag and cement, leading to the formation of C-S-H gel, which plays a role in enhancing the mechanical and durability properties of concrete.

Crack Resistance under Compressive Stress of Concrete Made Using Granulated Blast-furnace Slag Sand

Crack Resistance under Compressive Stress of Concrete Made Using Granulated Blast-furnace Slag Sand

Influence of Granulated Blast Furnace Slag Sand as Fine Aggregate on the Resistance Against Sulphate and Chloride Solution of Self-Cured Geopolymer Concrete

Influence of Granulated Blast Furnace Slag Sand as Fine Aggregate on the Resistance Against Sulphate and Chloride Solution of Self-Cured Geopolymer Concrete

Analysis of Strength of Concrete with Partial Replacement of Cement with Fly Ash and Fine Aggregate with Blast Furnance Slag Sand

The utilization of waste materials from the industries has been continuously gaining emphasis in the construction work recently. The present work is to use Processed Granulated Blast Furnace Slag Sand and Fly ash as combined replacement for river sand and ordinary Portland cement respectively. M35 grade of concrete with W/C 0.4 will be adopted with two percentages of cement replacement by Fly Ash i.e, 30% and 40%, along with this the slag sand is varied from 0% to 100% in step of 20%. In first variation, 30% Fly Ash is replaced by cement and slag sand is varied as 0%, 20%, 40%, 60%, 80% and 100%. In second variation, 40% GGBS is replaced with cement and slag sand is varied as 0%, 20%, 40%, 60%, 80%, and 100%. For all mixes compressive strength, split tensile and flexural strength will be determined at different days of curing. The strength of cube specimens, cylinders and beams will be determined and compared with conventional concrete specimens. The beams are tested for flexure, under two point loading condition. Different parameters will be investigated in detail. In this paper literature is reviewed in detail to understand the experimental analysis.

Energy consumption characteristics of concrete using granulated blast-furnace slag sand related to nucleation and propagation of microcracks

Recently, highly durable precast concrete using granulated blast-furnace slag sand (BFS) has been actively studied in Japan. Since BFS has a latent hydraulicity under alkaline conditions, it will improve the long-term strength and durability of concrete. In this study, to investigate the mechanisms of durability improvement of concrete with BFS, the energy consumption characteristics related to nucleation and propagation of microcracks in concrete specimens subjected to cyclic compressive loading are experimentally investigated. BFS concrete specimens with water-to-cement ratios of 0.35 and 0.50 are prepared and tested at material ages of 28 and 91 days. Normal concrete specimens using river sand are also prepared for comparison. Several types of energies are calculated from the areas under the stress–strain curves. The results show that, for the same water-to-cement ratio and the upper-limit stress ratio, the energy required to form microcracks at the initial loading, as well as the consumed energy in the constant region, are smaller for BFS concrete than for normal concrete. Thus, it is concluded that the damage done to BFS concrete during initial loading, as well as in the constant region during a fatigue process, is less than that done to normal concrete.

Guideline on Design, Manufacture and Construction Methods of Precast Concrete with Granulated Blast-Furnace Slag Sand

Guideline on Design, Manufacture and Construction Methods of Precast Concrete with Granulated Blast-Furnace Slag Sand

Improvement of Durability of Precast Concrete Member by Granulated Blast Furnace Slag Sand

Concrete deck slabs of bridges are often deteriorated by heavy traffic and freezing and thawing actions. Spraying salt during the winter further promotes the deterioration of concrete. Some reports estimate that the length of highway roads requiring the renewal of deteriorated concrete slabs exceeds 230 km. In order to extend the lifespan of damaged bridge girders, the load for these girders must not be increased. This means that prestressed concrete (hereafter, PC) members are desirable to sustain bridge life, because they can be thinner than reinforced concrete (hereafter, RC) members. In addition, to shorten the period of traffic regulation during renewal construction, precast members should be applied. One problem in manufacturing durable precast concrete is steam curing. When the temperature, period, or both of the steam curing process are inadequate, the effect of air-entraining (hereafter, AE) agents is lost because the warmed air trapped by the AE agent expands and escapes from the concrete. Another problem is concrete fatigue. It is well known that the fatigue lives of concrete slabs in wet conditions are much shorter than those in dry conditions. Concrete slabs are waterproofed immediately after construction, but the waterproofing can be fractured soon after opening bridges, and water can reach the concrete surface. The lifespan of concrete slabs in contact with water often depends on the fatigue of the concrete. Granulated blast furnace slag sand (hereafter, BFS) can enhance the resistance to freezing and thawing actions without using AE agents. Therefore, the resistance to freezing and thawing of concrete mixed with BFS is not damaged by steam curing. The fatigue of concrete in water is also improved by the addition of BFS. Furthermore, BFS can reduce the drying shrinkage of concrete. It is advantageous to restrict the loss of prestress in PC. This study shows that precast PC members with high durability can be manufactured when granulated blast furnace slag is used as a fine aggregate in the concrete. BFS reacts with cement hydrates. It is well known that the carbonation of concrete with ground granulated blast furnace slag (hereafter, GGBF) is much greater than that with ordinary binder. However, BFS does not accelerate the carbonation of concrete. When using granulated blast furnace slag as a fine aggregate, no disadvantage in the concrete properties is detected.

高炉スラグ細骨材を用いたコンクリートの凍結融解作用後の水中疲労に関する研究

Many concrete deck slabs of bridges have been deteriorated by heavy traffic, and freezing and thawing action. The water through the broken waterproof layer promotes the deterioration of concrete much more. Concrete used in replacements should have high resistance against freezing and thawing attack and fatigue in water. In this study, it is shown that the resistance to freeze and thaw attack can be improved by granulated blast furnace slag sand even without AE agent. The resistance to freeze and thaw attack of non-AE concrete with granulated blast furnace slag is almost same as that of AE concrete with the ordinary crushed sand. The fatigue of concrete suffered from freeze and thaw attack depends on the type of binder. When the crushed sand is used, the fatigue of concrete with high early strength Portland cement suffered from freeze and thaw attack is lower than that with ordinary Portland cement. When blast furnace slag sand is used, the tendency is almost same as when crushed sand is used. However, when blast furnace slag sand is used, the fatigue of concrete suffered from freeze and thaw attack can be improved with water curing period. It is also shown in this paper that blast furnace slag sand reacts with water and improve the durability of concrete.

Caking of Granulated Blast Furnace Slag Sand and Its Suppressive Technique

Caking of Granulated Blast Furnace Slag Sand and Its Suppressive Technique