Amount Of Ground Granulated Blast Furnace Slag Research Articles

The development of a fly ash-based geopolymer for extrusion-based 3D printing, along with a printability prediction method

This paper presents insights into the design and development of a geopolymer consisting of fly ash and ground granulated blast furnace slag (GGBFS) usable for extrusion-based 3D printing. It also reports on factors influencing the printability of the geopolymer, such as the amount of GGBFS, the solids content, mixing time, and activator ratio. Besides measuring the setting behaviour, the yield stress, and the ultrasonic velocity, we also conducted a modified flow spread test to investigate the geopolymer’s early physical material properties. We also used analytical methods (SEM, XRD, and TG) to explain its physical behaviour. We introduced an adjusted test for the flow spread (VFS test), which gives information about the thixotropic behaviour depending on the shear stress and the opentime for printing. By comparing the derivatives of the yield stress curve with printing tests on an XYZ gantry printer and analysis of the yield stress measurement’s transition point, we also present a unique method that allows researchers to assess the printability of the geopolymer solely on one small-scale laboratory tests without requiring printing tests on a physical 3D printer.

High-strength and high-toughness alkali-activated composite materials: Optimizing mechanical properties through synergistic utilization of steel slag, ground granulated blast furnace slag, and fly ash

In this study, the synergistic utilization of steel slag (SS), ground granulated blast furnace slag (GGBS), and fly ash (FA) was investigated to optimize the mechanical properties of high-strength and high-toughness alkali-activated composite materials (AAM). The research focused on understanding how varying ratios of these components affect the workability, compressive strength, elastic modulus, tensile strength, and tensile deformation capacity of high-strength and high-toughness AAM. A key part of the study involved optimizing the SS-GGBS-FA ternary cementitious system in high-strength and high-toughness AAM using the simplex-centroid design methodology. The findings reveal that changes in the proportions of SS, GGBS, and FA predominantly influence the flowability of high-strength and high-toughness AAM to a limited extent. Notably, the amount of GGBS in the cementitious mix significantly affects the compressive strength and elastic modulus of the material. A synergistic enhancement of the tensile properties was observed due to the combined effect of SS, GGBS, and FA. An optimal tensile deformation performance was achieved with approximately 15% SS. For an ideal balance of properties, including tensile strength above 8.1 MPa, ultimate tensile strain exceeding 6.4%, and compressive strength over 95 MPa, the study recommends maintaining SS between 7.5% and 11.5%, GGBS between 31.5% and 35.5%, and FA between 55.5% and 58.5%. These insights are crucial for the design and practical engineering applications of the SS-GGBS-FA ternary cementitious system in high-strength and high-toughness AAM.

Cryosuction Experiments on Concrete Containing Ground Granulated Blast-Furnace Slag: Influence of Temperature, Air Entrainment And Salt

Abstract Frost deterioration of concrete is an important durability issue for structures exposed to high degree of saturation, low temperatures and de-icers. The material can then be severely damaged with internal cracking and/or scaling of the surface, which can lead to e.g. reduced protection of the reinforcement and loss of load bearing capacity. Experiments with liquid uptake in concrete using different temperature cycles was made to study cryosuction. The material used was concrete with different air content and different replacement levels of ground granulated blast-furnace slag (GGBS). The concrete samples were preconditioned by capillary suction. Three temperature conditions were used: constant temperatures of +20 °C and -20 °C, and temperature that cycled between -20 °C and +20 °C. As liquid medium, deionized water and a 3% NaCl salt solution were used. Air entrainment generally increased the liquid uptake. The amount of GGBS and the NaCl concentration in the liquid did not have any significant impact on the liquid uptake in these experiments.

Towards Sustainable Stabilization: Utilizing Waste Material as Binder

The expansion and contraction of black cotton soil makes it difficult to build structures on it. The expansion and contraction behavior of black cotton soil must be adapted to make it suitable for construction purposes. This research is an attempt to evaluate the geotechnical characteristics of black cotton soil by performing laboratory testing incorporating ground granulated blast furnace slag (GGBFS) (10, 20, 30 and 40%) and polypropylene fiber (0.5, 1 and 1.5%) so as to use the combination as subgrade material. Various laboratory testing’s such as consistency limits, compaction and California bearing ratio (CBR) tests were conducted on varying amount of both the materials. The laboratory tests revealed that adding the right amount of GGBFS and polypropylene fiber alone or in combination improved the geotechnical features of black cotton soil (BCS). The mix obtained does not only solve the problems associated with BCS but also provides a cost effective solution for soil stabilization.

Curing Effect on Durability of Cement Mortar with GGBS: Experimental and Numerical Study.

In this paper, supplementary cementitious materials are used as a substitute for cement to decrease carbon dioxide emissions. A by-product of the iron manufacturing industry, ground granulated blast-furnace slag (GGBS), known to improve some performance characteristics of concrete, is used as an effective cement replacement to manufacture mortar samples. Here, the influence of curing conditions on the durability of samples including various amounts of GGBS is investigated experimentally and numerically. Twelve high-strength Portland cement CEM I 52.5 N samples were prepared, in which 0%, 45%, 60%, and 80% of cement were substituted by GGBS. In addition, three curing conditions (standard, dry, and cold curing) were applied to the samples. Durability aspects were studied through porosity, permeability, and water absorption. Experimental results indicate that samples cured in standard conditions gave the best performance in comparison to other curing conditions. Furthermore, samples incorporating of GGBS have superior durability properties. Permeability and water absorption were improved by and , respectively, compared to the reference sample. Thereafter, data from capillary suction experiments were used to numerically determine the hydraulic properties based on a Bayesian inversion approach, namely the Markov Chain Monte Carlo method. Finally, the developed numerical model accurately estimates the hydraulic characteristics of mortar samples and greatly matches the measured water inflow over time through the samples.

Long-Term Strength Evolution in Ambient-Cured Solid-Activator Geopolymer Compositions

The major downsides of cement manufacturing are the high CO2 emissions and high energy usage. Geopolymers, which are fabricated by activation of blends of fly ash (FA) and ground granulated blast furnace slag (GGBFS) using an alkaline activator, offer a promising solution to this issue. However, to enhance the replacement of cement in construction applications, geopolymer compositions have to be designed such that they can be activated on site by just adding water, similar to how cements are used. Therefore, the present work uses solid sodium metasilicate (MS, Na2SiO3) as the alkaline activator in order to design an add-water-style FA/GGBFS-based geopolymer composition. These compositions were designed by optimising the binder (FA/GGBFS) ratio, Na2SiO3/binder ratio, and water/binder ratio individually to assess the effects of these parameters on the setting times and mechanical (flexural and compressive) strengths over extended curing times (three months). The major factors affecting the strength development and setting times (initial and final) were the amounts of GGBFS and Na2SiO3, with the former demonstrating the more dominant effect. The consistent strength development with curing time was attributed to calcium aluminium silicate hydrate (CASH) gel formation in the early curing times which was affected by the slag addition levels, and sodium aluminium silicate hydrate (NASH) gel formation at later curing times which was influenced by the metasilicate addition levels. The metasilicate amounts were observed to impact on CASH gel formation in early stage curing. Geopolymer compositions with FA/GGBFS ratio of 35/65 and MS/water ratios of 0.2 showed high compressive strengths of ~70 MPa at 28 days, which are superior to values seen in conventional ordinary Portland cement (OPC) mixes for the same curing times.

Ambient-cured geopolymer mortars prepared with waste-based sands: Mechanical and durability-related properties and microstructure

In recent years, the use of industrial by-products and waste-based materials in the construction industry has received significant attention to develop eco-friendly and greener construction materials with the aim of reducing the impact of construction industry on the environment. The development of new concretes where cement is replaced with industrial by-products, such as ground granulated blast furnace slag (GGBS) and fly ash (FA), and natural sand (NS) is replaced with waste-based sands, such as lead smelter slag (LSS) and glass sand (GS), would lead to enormous environmental and health benefits by enabling the use of abundant wastes, reducing the extraction of non-renewable natural resources, and reducing the CO2 emissions associated with concrete production. This paper presents an experimental study on the properties of geopolymer mortars prepared with FA/GGBS, LSS, and GS under ambient curing condition. A total of 12 batches of geopolymer mortars were manufactured and experimental tests were conducted to determine the flowability, hardened density, compressive strength, direct tensile strength, water absorption, and drying shrinkage of each batch together with the alkali-silica reaction (ASR) expansion of batches containing GS. Microstructural analysis was undertaken to describe the reasons for the obtained experimental results. The results show that the compressive and tensile strength of geopolymer mortars increase with an increase in the amount of GGBS. The results also show that an increase in the GGBS amount leads to a decrease in the water absorption of geopolymer mortars. Owing to the lower void amount at the binder-sand interaction zones, LSS- and GS-based geopolymer mortars containing up to 50% GGBS exhibit superior mechanical properties compared to those of their NS-based counterparts. These highly promising findings suggest that the full replacement of NS by LSS and GS can provide an attractive avenue to reduce the environmental impact of abundant waste products and conserve non-renewable natural resources.

Frost resistance of concretes containing ground granulated blast-furnace slag

The paper deals with the influence of addition of ground granulated blast-furnace slag (GGBS) on the frost resistance of concrete. GGBS is a valuable modifier of concrete, having the latent hydraulic properties and particularly improving the chemical resistance of concrete. However, the performance of concretes with blast-furnace slag under freezing and thawing action is still not explained fully and remains a subject to discussion. The authors have investigated the concretes containing various amounts of GGBS and the portland cement CEM I, with various values of water to binder ratio, with and without the use of air-entraining admixture. The results of research show that the addition of blast-furnace slag causes some worsening of the frost resistance of concrete. The extent of this worsening depends on the water to binder ratio and the aeration of the concrete. However, even under the least favourable conditions, the concretes with GGBS addition have met the requirements of frost resistance after 200 cycles of freezing and thawing, given in the Standard PN-B-06265.

RETRACTED: The effects of ZrO2 nanoparticles on properties of concrete using ground granulated blast furnace slag as binder

In the present study, flexural strength together with pore structure, thermal behavior, and microstructure of concrete containing ground granulated blast furnace slag (GGBFS) with different amounts of ZrO2 nanoparticles has been investigated. Portland cement was replaced by different amounts of GGBFS, and the properties of concrete specimens were investigated. Although it negatively impacts the physical and mechanical properties of concrete at early ages, utilizing up to 45 wt% GGBFS was found to improve these properties at later ages. ZrO2 nanoparticles with the average particle size of 15 nm were partially added to the concrete with the optimum content of 45 wt% GGBFS, and physical and mechanical properties of the specimens were measured. ZrO2 nanoparticle as a partial replacement of cement up to 3 wt% could accelerate C–S–H gel formation as a result of increased crystalline Ca(OH)2 amount at the early age of hydration and hence, increase flexural strength of the concrete. The more the ZrO2 content of n...

RETRACTED ARTICLE: Effects of Al2O3 nanoparticles on properties of self compacting concrete with ground granulated blast furnace slag (GGBFS) as binder

In this work, strength assessments and percentage of water absorption of self compacting concrete containing ground granulated blast furnace slag (GGBFS) and Al2O3 nanoparticles as binder have been investigated. Portland cement was replaced by different amounts of GGBFS and the properties of concrete specimens were investigated. Although it negatively impacts the physical and mechanical properties of concrete at early ages of curing, GGBFS was found to improve the physical and mechanical properties of concrete up to 45 wt% at later ages. Al2O3 nanoparticles with the average particle size of 15 nm were added partially to concrete with the optimum content of GGBFS and physical and mechanical properties of the specimens were measured. Al2O3 nanoparticle as a partial replacement of cement up to 3.0 wt% could accelerate C-S-H gel formation as a result of increased crystalline Ca(OH)2 amount at the early ages and hence increase strength and improve the resistance to water permeability of concrete specimens. The increase of the Al2O3 nanoparticles’ content by more than 3.0 wt% would cause the reduction of the strength because of the decreased crystalline Ca(OH)2 content required for C-S-H gel formation. Several empirical relationships have been presented to predict flexural and split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of the peaks related to hydrated products in X-ray diffraction results, all indicate that Al2O3 nanoparticles could improve mechanical and physical properties of the concrete specimens.

Effect of Fly Ash and Ground Granulated Blast-Furnace Slag on Sulfuric Acid Resistance of Concrete

The effect of Fly ash (FA) and ground granulated blast-furnace slag (GGBS) on sulfuric acid resistance of concrete has been investigated in this study. Cement was replaced by FA with the incorporation amount from 20% to 50% or by GGBS from 35% to 65%. Results indicate that with an increase in fly ash replacement amount, the sulfuric acid resistance of concrete was improved. Sulfuric acid resistance of concrete with GGBS was improved only when the replacement amount of GGBS exceeds 50%. The basic reason for deterioration of concrete in sulfuric acid is the degradation of C-S-H gel in matrix. Increasing the content of SiO2 in cement paste can improve the acid resistance of concrete.