Influence Of Ground Granulated Blast Furnace Slag Research Articles

Influence of GGBFS and alkali activators on macro-mechanical performance and micro-fracture mechanisms of geopolymer concrete in split Hopkinson pressure bar tests

With superior low-carbon emission and low-resource consumption, geopolymer concrete (GPC) is receiving increasing attention as an optimal alternative to conventional building materials for cleaner and sustainable construction. However, the practical application of GPC poses great challenges since its dynamic mechanical performance remains far from well understood. In this study, via a split Hopkinson pressure bar (SHPB) system, a series of dynamic compression tests at strain rates of 45 s-1 to 150 s-1are conducted on GPC specimens with different alkaline activators (AAS)-binder mass ratios (i.e., 10%, 15%, 20%, and 25%) and ground granulated blast furnace slag (GGBFS)-binder mass ratios (i.e., 0%, 30%, 50%, 70%, and 100%). Our testing results comprehensively explored the influence of mix proportions and loading rates on the dynamic mechanical performance of GPC, including the dynamic strength and deformation characteristics, energy evolution and utilization, and progressive failure behavior. The permanent strain, energy dissipation density, and dynamic strength of GPC specimens generally increase with increasing strain rate, while the average fragment size decreases. Under higher loading rates, GPC specimens are featured by denser microcracks, shorter propagation paths, and more prominent stepwise fractures. In addition, GGBFS has a greater impact on dynamic strength, strain rate sensitivity, and energy utilization than AAS. Micro-fracture effect of GPC with different mix proportions is investigated. An appropriate content of alkaline activator (i.e., 20%) and higher GGBFS content (i.e., 100%) promotes the binder depolymerization-aggregation reaction, reduces initial defects inside concrete specimens, and facilitates a more compact block structure.

Influence of GGBFS and Silica Fume on the Properties of High-Strength Self-Compacting Concrete

When the compaction of concrete becomes challenging to carry out, Self-Compacting Concrete (SCC) is considered as an alternative to ordinary concrete. The aim of the present work is to obtain high-strength SCC by substituting Ground Granulated Blast Furnace Slag (GGBFS) and Silica Fume (SF) for cement. GGBFS and SF have been extensively employed as admixtures in recent years to produce high-strength concrete. SCC was created as a reference mix without any mineral admixtures, whereas the other mixes had varying amounts of GGBS and SF. The remaining six mixtures contained various concentrations of GGBFS from 10 to 30 percent with variations of 10% and silica fume from 5 to 15 percent with variations of 5 percentile. As workability is the primary attribute of SCC, various flowability features, including the Slump test, V funnel, and L box test were recognized. Studies on mechanical performance and durability properties were conducted. At 28 days, a ternary combination of 30% GGBS and 5% SF reaches its maximum compressive strength of 70.12 MPa. Also, when SF is replaced with 5% and GGBFS with 30% by weight of cement, the results showed better improvement in durability.

Improving the volume stability of the β-hemihydrate phosphogypsum – Cement system by incorporating GGBS

Using Portland cement to improve the properties of β-hemihydrate gypsum (β-HPG) is a convenient and economical measure. However, the volume stability of the β-HPG-cement system is worrying because the hydration product ettringite is likely to cause expansion damage. This study introduced ground granulated blast furnace slag (GGBS) to enhance the β-HPG-cement system's volume stability. The influence of GGBS on the performance of composite systems was investigated, and the mechanism behind it was discussed. The results showed that when 5 % cement and 15 % GBBS coexisted, the compressive strength of the composite system reached 41.0 MPa, and the softening coefficient was 0.73. As for the volume stability, the 28 d volume change of the specimen containing 5 % cement and 5 % GGBS was consistent with that of the blank group. XRD, TG-DSC, and SEM results showed that the introduction of GGBS increased the content of ettringite but affected its crystal morphology and formation position. Most of the ettringites were thick rods and randomly distributed in the pores, which was speculated to be one reason for the composite system's enhanced volume stability. The altered crystallization driving force of ettringite due to the consumption of OH– by hydration of GGBS was considered responsible for its altered morphology and position. These research results showed that the morphology and location of ettringite had more influence on the expansion properties in the β-HPG -cement-GGBS system, which could provide theoretical guidance for designing composite materials with high-volume stability.

One-part eco-friendly alkali-activated concrete – An innovative sustainable alternative

The primary objective of this study is to develop an eco-friendly one-part alkali-activated concrete (OPAAC) by incorporating a combination of fly ash (FA), ground granulated blast furnace slag (GGBS), and micro silica (MS). In this investigation, the proportion of MS is maintained at 20% of FA, while the maximum replacement of FA with GGBS is set to 60%, varying in 20% intervals (i.e., 0%, 20%, 40%, and 60%). Further, the natural aggregates (NA) are substituted with recycled coarse aggregates (RCAs), ferrochrome slag aggregates (FCSAs), or a combination of both. The influence of GGBS and alternative aggregates (RCAs, FCSAs) on the mechanical properties of OPAAC is thoroughly examined. To provide a comprehensive assessment, the properties of OPAAC are compared against Ordinary Portland Cement (OPC) concrete (CC) of equivalent grades. Additionally, microstructural and mineralogical investigations are conducted to determine the formation of distinct hydration products, utilizing scanning electron microscopy (SEM) and X-ray diffractometry (XRD) techniques. In OPAAC containing FA, the primary hydration products identified are alkaline alumino silicate hydrates (CASH and NASH). As the GGBS content increases, calcium silicate hydrate (CSH) becomes the predominant hydration product. Furthermore, in order to assess the sustainability of OPAAC, an analysis of embodied CO2 emissions is performed, and the results are compared with CC and alkali-activated concrete. Notably, OPAAC comprising 40% FA replaced with GGBS, 50% RCAs, and 50% FCSAs demonstrates the most favourable mechanical properties and exhibits lower CO2 emissions.

Mechanical and microstructural properties of cemented marine dredged clay with pre-hydrated ground granulated blast furnace slag

Marine dredged clay (MDC) is treated with large amounts of cement before being used as construction materials due to its highly water content, leading to a strong demand of economically friendly treatment method. Ground granulated blast furnace slag (GGBS) has been used in concrete production to replace partial cement, but its application in cementing MDC is rarely been investigated. Furthermore, previous studies ignore the self-hydration capacity of GGBS, which may weaken the effectiveness or cause the overuse of GGBS. This study provides a new mixing method (MMII) in treating MDC by pre-hydrating GGBS before mixing with cement, and conducts a series of laboratory tests on the cemented MDC. The influence of GGBS and the mixing method on the mechanical and microscopic properties was examined. The results show that the recommended pre-hydration time is 16 h. The cemented MDC with GGBS obtains higher strength and lower hydraulic conductivity than that of cement-treated MDC with pure cement. Under the influence of MMII, more hydration products are generated due to the two times of hydration, the UCS is improved by up to 20%, the hydraulic conductivity is reduced by up to 17% accordingly. Meanwhile, the size of Ca(OH)2 (CH) decreases to generate calcium silicate hydrate (CSH). By only change mixing order, the engineering performance of cemented MDC with GGBS is improved significantly, showing great engineering benefits and economic values in treating MDC by pre-hydrating GGBS.

The Influence of GGBFS as an Additive Replacement on the Kinetics of Cement Hydration and the Mechanical Properties of Cement Mortars

Granulated blast furnace slag (GBFS) is a byproduct of the iron production process. The objective of this study is to determine the effects of ground granulated blast furnace slag (GGBFS), used as a replacement admixture (0–40 wt.%) for ordinary Portland cement (OPC), on the setting time, the heat of hydration, and the mechanical properties of cement mortar. The influence of GGBFS as a replacement additive on the setting time shows that it has an accelerating effect on cement hydration. Calorimetric measurements were performed on the cement paste system to determine the effects of GGBFS on the hydration of OPC. Calorimetric measurements carried out show that the replacement of GGBFS in an amount up to 40 wt.% reduces the total heat of hydration by up to 26.36% compared to the reference specimen. The kinetic analysis performed on the calorimetric data confirms the role of GGBFS as an accelerator by shortening the time during which the process of nucleation and growth (NG), as the most active part of hydration, is reduced up to 2.5 h. The value of the Avrami–Erofee constant indicates polydispersity and heterogeneous crystallization. Mechanical tests of cement mortars were performed after 3, 7, 14, 28, 70, and 90 days of hydration and showed that replacement addition of GGBFS slightly reduced the mechanical properties in the early phase of hydration, while in the later phase of hydration it contributed to an increase in the mechanical properties.

Effect and influence of GGBS on properties of ambient cured self-compacting geopolymer concrete

The sustainable manufacture of self-compacting geopolymer concrete (SCGC), which has a lower carbon footprint compared with traditional concrete, reflects environmentally friendly concrete. In addition to the physical properties, this article presents an analysis of the fresh and mechanical properties of self-compacting geopolymer concrete. Some parameters such as varied sodium hydroxide molarity from 8 M to 16 M, sodium hydroxide/silicate solution ratio from 1:2.5 alkaline to GGBS, extra water ratio, GGBS content from 400 Kg/m3 to 500 Kg/m3. The current experimental evaluation examines the effectiveness of GGBS in improving SCGC workability and compressive strength due to durability. The sodium hydroxide molarity rises marginally reducing the fresh properties of self-compacting geopolymer concrete. As in the case of self-compacting concrete (SCC) with Portland cement, the durability properties of self-compacting geopolymer concrete are just a fraction of the compressive strength. The durability properties of self-compacting geopolymer concrete are adversely affected by rising test results of physical properties. Out of 5 different SCGC mix series, the optimum mix was achieved when a hundred percent Ground Granulated blast furnace slag (GGBS) and fifty percent river and M-sand were used, which not only showed better compressive strength and durability but also produced adequate workability within the EFNARC Self-Compacting Concrete (SCC) limits.

Influence of GGBFS on corrosion resistance of cementitious composites containing graphene and graphene oxide

Previous studies extensively focused on the mechanical characteristics of cementitious composites containing carbon-based nanomaterials. However, no specific research has concentrated on corrosion performance. Hence, the present study intends to experimentally determine the effect of graphene (G) and graphene oxide (GO) on the corrosion resistance of composites by conducting various tests, including accelerated corrosion, linear polarization, half-cell potential, and electrical resistivity tests. Two different dosages, 0.03% and 0.06%, are considered for nanomaterials. Ground granulated blast furnace slag (GGBFS) is also used to adjust the fresh properties of composites with different percentages (15%, 30%, and 45%). Results show the synergistic influence of nanomaterials (0.03%) and GGBFS (30%) as being at the root of a considerable increase in compressive strength. They also indicate that GO has a stronger synergy with GGBFS in improving compressive strength as compared to G. However, flexural test results show that G is more compatible with GGBFS due to the reinforcing effect in controlling crack width developed in bending. Further, the results strongly confirm that adding GGBFS in nanoconcrete significantly improves the corrosion resistance of composites. Moreover, among all mixtures, composite with 45% GGBFS and 0.03% GO shows the best performance against the corrosive environment, even for saltwater immersion.

Influence of GGBFS and silica fume on characteristics of alkali-activated Metakaolin-based concrete

Alkali-activated or geopolymer composites have been introduced as a promising green alternative to ordinary Portland cement concretes and mortars. Metakaolin (MK) is a common source material produced from the calcination of kaolin, which has been widely employed for geopolymer synthesis. The present study involves testing thirteen alkali-activated concrete mixes divided into two groups to investigate their fresh and mechanical properties. The two groups attempted to study the effect of partial replacement of MK by ground granulated blast furnace slag (GGBFS) and silica fume (SF) (ranging from 5% to 30% by MK weight). The effect of the water-to-solids ratio for MK-GGBFS and MK-SF concretes was also studied. The investigated fresh and mechanical properties were slump, density, compressive strength, compressive strength rate of development, splitting tensile strength, water absorption, abrasion resistance, and ultrasonic pulse velocity. The partial replacement of MK by GGBFS of up to 10% caused about 10% reduction in the compressive strength of geopolymer but enhanced early strength development. The conclusions derived from the study are supported by XRD analysis and SEM images. Models are proposed for estimating the mechanical properties of geopolymer concrete as a function of either the molar ratios and the aggregate content or compressive strength.

Effects of GGBFS on hydration and carbonation process, microstructure, and mechanical properties of NHL-based materials

Natural hydraulic lime (NHL) is an inorganic building material with hydraulic and air-hardening properties, having exceptional application in restoring ancient buildings compared to Portland cement and ancient air-hardening lime. However, the characteristic of slow performance development limits its application field. This study used ground granulated blast furnace slag (GGBFS) to replace parts of NHL. The hydration heat release, phase composition, micromorphology, pore structure, and physical and mechanical properties of GGBFS-NHL (S-NHL) based materials in the hardening process are investigated in-depth. The influence of GGBFS on the hardening process and performance development of NHL are systematically evaluated. The NHL is dominated by the hydration reaction of C2S to produce C–S–H in the early stage (less than 28 days). Moreover, C3AH6, CASH4, C4AĈH11, and C–S–H gel generated by the reaction of GGBFS with Ca(OH)2 changes the composition of hardened products, including the microstructure of the hardened paste. The higher the dosage of GGBFS, the more the hydration products in the NHL-based paste. The NHL-based paste gradually hardens with increasing age, mainly due to carbonation reaction. Moreover, its pore structure gradually densifies with curing age, and the average pore size and total pore volume of S-NHL decrease gradually with increasing GGBFS content. GGBFS significantly influences the mechanical properties and weight of the NHL-based mortar development. In addition, the S-NHL mortar's early and long-term mechanical strength increased significantly with increasing GGBFS.

Influence of Ground-Granulated Blast-Furnace Slag on the Structural Performance of Self-Compacting Concrete

Influence of Ground-Granulated Blast-Furnace Slag on the Structural Performance of Self-Compacting Concrete

Effects of Admixtures on Energy Consumption in the Process of Ready-Mixed Concrete Mixing

The production and utilization of concrete and concrete-based products have drastically increased with the surge of construction activities over the last decade, especially in countries such as China and India. Consequently, this has resulted in a corresponding increase in the energy used for the production of ready-mixed concrete. One approach to reduce the cost of concrete manufacturing is to reduce the energy required for the manufacturing process. The main hypothesis of this study is that the power required for mixing the concrete can be reduced through the use of mineral admixtures in the mix design. Optimization of energy consumption during mixing using admixtures in concrete manufacturing is the predominant focus of this article. To achieve this objective, power consumption data were measured and analyzed throughout the concrete mixing process. The power consumption curve is the only source to distinguish the behavior of the different materials used in the concrete in a closed chamber. In the current research, fly ash and ground granulated blast-furnace slag (GGBS) were used as mineral admixtures to produce ready-mixed concrete. The experimental study focused on the influence of GGBS and fly ash on power consumption during concrete mixing. The results indicated that the use of a higher content of GGBS is more beneficial in comparison to the use of fly ash in the mix due to the lower mixing time required to achieve homogeneity in the mixing process. It was found that the amount of energy required for mixing is directly related to the mixing time for the mix to achieve homogeneity.

Influence of GGBS- based Geopolymer Aggregate on Compressive Strength of Concrete

Concrete is the most widely used building component in the world due to its versatility, low cost and durability. Most common coarse aggregate used in the construction are stones which is obtained from quarry. The demand for coarse aggregate in the construction industry has consequently increased due to the extensive use of natural resources. It has necessitated research into alternative materials of construction. This research aims to find the alternate material for coarse aggregate by using Ground Granulated Blast furnace Slag (GGBS) clinker and to determine the hardened properties of non-conventional concrete in M20 Grade. The aggregate utilized in this work is an Eco friendly material, which replace the conventional coarse aggregate to preserve the depletion of natural resources. It is abundantly available than the conventional aggregate and reduce pollution. This paper focuses on investigating characteristics of concrete with replacement of coarse aggregate by GGBS Clinker. This study deals with the GGBS clinker advantages and limitations in concrete. The usage of GGBS clinker serves as a replacement of conventional aggregate to reduce the depletion of conventional building materials. It serves as an Eco friendly way of utilizing the by- product without dumping it on ground.

Optimisation of rheological parameters, induced bleeding, permeability and mechanical properties of supersulfated cement grouts

Presenting a promising option that could be used to encapsulate nuclear waste material for disposal, supersulfated cement (SSC) is, again, receiving wide attention among research community as a cementitious system that has noteworthy properties. It is also an environmentally friendly cement since it is mainly composed of ground granulated blast furnace slag (GGBS) that is activated by a sulphate source such as gypsum, hemihydrate or anhydrite. Although there is some research on SSC, little research work has focused on modelling the effects of the various parameters using a statistical approach which is the aim of this paper. The effect of dosages of GGBS, anhydrite (ANH) and water-to-binder ratio (W/B) on the fresh and rheological parameters, induced bleeding, permeability, compressibility, and compressive strength of supersulfated grouts was investigated. Then, statistical models and isoresponse curves were developed to capture the significant trends of the tested parameters using factorial design approach. The models suggested that that W/B had significantly higher influence on most of the parameters tested while the influence of GGBS and ANH and their interactions varied depending on the parameter in question. The findings of this study show the importance of understanding the role of and optimising the relevant key factors in producing SSC fit-for-purpose. The statistical models developed in this paper can facilitate optimizing the mixture proportions of grouts for target performance by reducing the number of trial batches needed.

Influence of GGBS and Marble Dust on Mechanical Properties of Concrete

Concrete is a extensively used material in construction. Due to high tech upgrading, the concrete have been matured to augment the equity of concrete. Now a day’s various studies have been conducted to make concrete with waste materials with the intension of reducing cost and demand of materials. This paper investigates the mechanical goods of concrete using Ground Granulated Blast furnace Slag (GGBS) and Marble Dust (MD) as a limited replacement of cement and fine aggregate respectively. Based on previous literature survey, 40% of GGBS and 10, 20 and 30% of MD are taken for the present study. The present research work is aimed at studying the mechanical properties of M20 grade concrete using GGBS and MD. Compressive strength and Split tensile strength were carried out for 7, 28 and 56 days and insignificant increases in the strength were observed for concrete specimens admixed with GGBS and MD when compared with conventional concrete.

Influence of ground granulated blast furnace slag on cracking potential of high performance concrete at early age

In recent years, high performance concrete (HPC) has been fully developed and put into widespread use in the actual project. Ground granulated blast furnace slag (GGBFS) has been widely used in HPC as a mineral admixture to improve the comprehensive workability. Nowadays, Temperature Stress Test Machine (TSTM) has been used to investigate the cracking potential of concrete. The influence of GGBFS on the early-age cracking potential of HPC has been investigated. However, investigations on the influence of GGBFS on the early-age cracking potential of HPC under adiabatic condition at full uniaxial restraint degree by using TSTM remain lacking. Investigations on the early-age cracking potential of HPC with different GGBFS contents (0%, 20%, 35%, and 50%) under adiabatic condition at full uniaxial restraint degree by using TSTM were conducted in the present study. The experimental results and related analysis indicated that (1) the addition of GGBFS reduced early-age temperature rise, temperature drop, cracking stress, cracking temperature, and stress reserve of HPC; (2) the autogenous shrinkage and integrated criterion of HPC increased with the increasing GGBFS content at early age; (3) the early-age cracking potential of HPC increased with the increasing GGBFS content, and the optimal GGBFS content shall not exceed 20% in the present study.

Influence of GGBS on the Properties of Charge Chrome Based Geopolymer Concrete in Ambient Temperature

One of the most widely used materials in construction worldwide is concrete. Due to its cheap manufacturing and high strength it has been extensively used, leading to environmental problems. Thus, various alternatives have been suggested to concrete made from Ordinary Portland Cement (OPC), one among them being Geopolymer Concrete. Geopolymers are inorganic alumino-silicate polymers synthesised from materials of geological origin or by-product materials such as fly ash which are rich in silicon and aluminium. Fly ash is available abundantly worldwide from thermal power plants whereas Ground Granulated Blast furnace Slag(GGBS) is obtained by quenching iron slag from a blast furnace in water or steam. Ferrochrome slag or charge chrome is a major solid waste generated from submerged electric arc furnaces during manufacturing of ferrochrome alloy. A major drawback of using fly ash based GPC is its requirement of high temperature for curing. The main purpose of this study was to evaluate the mechanical properties of ambiently cured fly ash based geopolymer concrete with ferrochrome slag partially replacing coarse natural aggregate and GGBS partially replacing fly ash. Present study indicates that the compressive strength increased with the increase in proportion of GGBS with respect to fly ash from 25 MPa at 10% replacement to 50MPa at 40% replacement.

Influence of ground granulated blast furnace slag on early-age cracking potential of internally cured high performance concrete

High performance concrete (HPC) with low water-to-binder (w/b) ratio has been used widely in the actual project. However, high autogenous shrinkage induced by the low w/b ratio would cause the residual tensile stress in HPC when the shrinkage is restrained. The cracking may occur in HPC if the residual tensile stress exceeds the developing tensile strength. Ground granulated blast furnace slag (GGBFS) has been used widely in the mixture of HPC as a kind of mineral admixture. The influence of GGBFS on the cracking potential of concrete has been studied. However, investigations on the influence of GGBFS on the early-age cracking potential of internally cured high performance concrete (ICC) with super absorbent polymers (SAPs) as an internal curing (IC) agent by using the ring test are still lacking. Investigations on the early-age cracking potential of ICC with different GGBFS contents (0%, 20%, 35%, and 50%) by using the ring test were conducted in the present study. Results and corresponding analysis showed that: (1) the free shrinkage strain, residual tensile stress, stress relaxation, cracking potential parameter, and stress rate of ICC with SAPs decreased with the increase of GGBFS content; (2) the early-age cracking potential of ICC with SAPs based on the cracking potential parameter and stress rate decreased with the increase of GGBFS content. The results in the present study could be used to evaluate the influence of GGBFS on the early-age cracking potential of ICC with SAPs.

Influence of ground granulated blast furnace slag on the early-age anti-cracking property of internally cured concrete

The influence of ground granulated blast furnace slag (GGBFS) on the mechanical properties and autogenous shrinkage of concrete has been studied. However, investigations on the influence of GGBFS on the early-age anti-cracking property of internally cured high performance concrete (ICC) with super absorbent polymers (SAPs) are still lacking. Investigations on the anti-cracking property of ICC with GGBFS were conducted under adiabatic condition at uniaxial restraint degree by using Temperature Stress Test Machine in the present study. Results and corresponding analysis showed that: (1) the addition of SAPs decreased the autogenous shrinkage, restrained tensile stress rate, and increased the temperature drop, as well as increased the anti-cracking property of high performance concrete; (2) the temperature rise, temperature drop and cracking stress of ICC under adiabatic condition decreased with the increase of GGBFS content; (3) the autogenous shrinkage and restrained tensile stress rate of ICC increased with the increase of GGBFS content; (4) the early-age anti-cracking property of ICC estimated by using integrated criterion decreased with the increase of GGBFS content.

In situ measurement of the rheological properties and agglomeration on cementitious pastes

Various factors influence the rheology of cementitious pastes, with the most important being the mixing protocol, mixture proportions, and mixture composition. This study investigated the influence of ground-granulated blast-furnace slag, on the rheological behavior of cementitious pastes. In tandem with the rheological measurements, fresh state microstructural measurements were conducted using three different techniques: A coupled stroboscope-rheometer, a coupled laser backscattering-rheometer, and a conventional laser diffraction technique. Laser diffraction and the coupled stroboscope-rheometer were not good measures of the in situ state of flocculation of a sample. Rather, only the laser backscattering technique allowed for in situ measurement on a highly concentrated suspension (cementitious paste). Using the coupled laser backscattering-rheometer technique, a link between the particle system and rheological behavior was determined through a modeling approach that takes into account agglomeration properties. A higher degree of agglomeration was seen in the ordinary Portland cement paste than pastes containing the slag and this was related to the degree of capillary pressure in the paste systems.