Alkali-Sulfate Activated Blended Portland Cements

2018 ◽  
Vol 276 ◽  
pp. 9-14 ◽  
Author(s):  
Pavel Krivenko ◽  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska
Keyword(s):  
Sodium Sulfate ◽  
Blast Furnace Slag ◽  
Pozzolanic Reaction ◽  
Portland Cements ◽  
Early Stages ◽  
Granulated Blast Furnace Slag ◽  
Sulfate Activation ◽  
Early Strength ◽  
Zeolite Tuff ◽  
Furnace Slag

Early strength of the blended Portland cements containing granulated blast furnace slag and natural pozzolanas (zeolite tuff, etc.) can be enhanced by the alkali-sulfate activation. High early strength of the blended Portland cements as a result of alkali-sulfate activation can be attributed to acceleration of pozzolanic reaction at the early stages and formation of more quantities of ettringite at the early stages of structure formation. The results of the study showed that with high amounts of sodium sulfate in the alkali-sulfate activator, contents of gypsum dihydrate as a setting regulator of the blended Portland cements could be reduced. The effect of sodium sulfate activator on properties of the blended Portland cements was studied and the results are discussed.

scholarly journals Early Strength Development of Soft Clay Stabilized by One-Part Ground Granulated Blast Furnace Slag and Fly Ash-Based Geopolymer

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiyao Zheng ◽  
Jun Wu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Soft Clay ◽  
Strength Development ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Early Strength ◽  
Furnace Slag ◽  
Water Binder Ratio

One-part or “just add water” geopolymer is a cementitious material, which is friendly to environment and users in applications. However, the mechanical behavior of the soft soil stabilized by one-part geopolymer is not well acknowledged. In this study, soft clay was stabilized with ground granulated blast furnace slag (GGBFS) and fly ash (FA)-based geopolymer, which is a mixture of solid aluminosilicate precursor (Al-Si raw materials: GGBFS and FA), solid alkali activator, and water. The objective was to adopt one-part geopolymer as an alternative soil binder to completely replace ordinary Portland cement (OPC) for stabilizing the soft clay and evaluate the effect of the factors (i.e., GBFS/FA ratio in Al-Si precursor, activator/Al-Si precursor ratio, and water/binder ratio) that influenced the early strength. Results showed that the increase of the FA content in the Al-Si precursor increased the unconfined compressive strength (UCS) values significantly through the geopolymerization process. The highest UCS values were achieved with 90% GGBFS to 10% FA in the precursor when the activator/precursor and water/binder ratio is 0.15 and 0.7, respectively. The UCS values of geopolymer-stabilized clay could reach 1.5 MPa at 14 days at ambient temperature, which is much higher than that of OPC-stabilized clay. The microstructure and mineralogy analyses indicated that the prolific hydration products, such as calcium silicate hydrate (C-S-H), calcium aluminum hydrate (C-A-H), and calcium aluminum silicate hydrate (C-A-S-H), contributed greatly to strengthen the soft clay by forming the soil skeleton and infilling among clay particles, while sodium aluminosilicate (N-A-S-H) gel is only served to fill the part of porosities in the soil and cannot effectively enhance the UCS of the one-part geopolymer-stabilized soft clay. This paper results suggested that one-part GGBFS-FA–based geopolymers have the potential to replace OPC in the manufacture of stabilized soft clay.

scholarly journals The effect of fly ash and granulated blast furnace slag on slip and tensile adhesion strength of tile adhesives mortars

2020 ◽  
Vol 322 ◽  
pp. 01017
Author(s):  
Michał Wieczorek
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Adhesion Strength ◽  
Blast Furnace Slag ◽  
Portland Cements ◽  
Optimal Amount ◽  
Functional Parameters ◽  
Granulated Blast Furnace Slag ◽  
Tensile Adhesion ◽  
Furnace Slag

In the formulations of adhesive mortars for tiles almost exclusively CEM I Portland cements are used. Practically no CEM II - CEM V cements with additives are used, although they are often produced with strength classes 32.5 R and some even 42.5R. Relationship between strengths of tile adhesives in which cement was partially replaced with fly ash and granulated blast furnace slag was studied. A fly ash was used in three different replacement levels from 5% to 25% by weight of either cement. The tensile adhesion were determined at 28 and 90 days after various conditioning conditions of the samples. The influence on the flexibility of mortars was also assessed. In small substitution levels, fly ash replacement increased the tensile adhesion strength. The results indicate that the optimal amount of fly ash and granulated blast furnace slag additive replacing a given amount of cement allows to obtain adhesive mortars for tiles with high functional parameters.

scholarly journals Effect of metakaolin replaced granulated blast furnace slag on fresh and early strength properties of geopolymer mortar

2018 ◽  
Vol 9 (4) ◽  
pp. 1557-1566 ◽  
Author(s):  
Ghasan F. Huseien ◽  
Jahangir Mirza ◽  
Mohammad Ismail ◽  
S.K. Ghoshal ◽  
Mohd Azreen Mohd Ariffin
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Strength Properties ◽  
Granulated Blast Furnace Slag ◽  
Early Strength ◽  
Furnace Slag

scholarly journals Performance of Ternary Class F Pulverised Fuel Ash and Ground Granulated Blast Furnace Slag Concrete in Sulfate Solutions

2017 ◽  
Vol 2 (7) ◽  
pp. 8 ◽  
Author(s):  
Ash Ahmed ◽  
John Kamau
Keyword(s):  
Blast Furnace ◽  
Sodium Sulfate ◽  
Blast Furnace Slag ◽  
Strength Deterioration ◽  
Granulated Blast Furnace Slag ◽  
Sulfate Solutions ◽  
Fuel Ash ◽  
The Individual ◽  
Furnace Slag ◽  
Intended Use

Durability of concrete is defined as its ability to resist deterioration after it has been exposed to the environment of its intended use. This work examined the performance of combined (ternary) Pulverised Fuel Ash (PFA) and Ground Granulated Blast Furnace Slag (GGBS) concrete in sulfate solutions of sodium sulfate (Na2SO4), magnesium sulfate (MgSO4) and mixed Na2SO4 and MgSO4, as well as its performance in water absorption. Investigations were carried out on replacements that were found to have achieved the highest compressive strengths as well as on 30% replacements from a previous study. From the results obtained, it was also found that at highest compressive strengths, the ternary concrete could be used with an advantage over the individual binary concretes in MgSO4 environments, whereas at a higher replacement, the ternary concrete could be used with an advantage over individual binary specimens in Na2SO4 and MgSO4 environments. For visual observations, it was concluded that the ternary concrete could be used with an advantage over the individual binary concretes in Na2SO4 and MgSO4 environments, whereas for strength deterioration, the results showed that the ternary specimens could be used with an advantage over individual binary concretes in both the MgSO4 and the mixed sulfate solutions. Generally, the ternary specimens showed some complimentary effect from the two materials.

scholarly journals Performance of Ground Granulated Blast-Furnace Slag and Coal Fly Ash Ternary Portland Cements Exposed to Natural Carbonation

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3239
Author(s):  
Rosa Abnelia Rivera ◽  
Miguel Ángel Sanjuán ◽  
Domingo Alfonso Martín ◽  
Jorge Luis Costafreda
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Coal Fly Ash ◽  
Portland Cements ◽  
Carbonation Process ◽  
Granulated Blast Furnace Slag ◽  
Natural Carbonation ◽  
Furnace Slag

Ternary Portland cements are new cementitious materials that contain different amounts of cement replacements. Ternary Portland cements composed of granulated blast-furnace slag (GBFS), coal fly ash (CFA), and clinker (K) can afford some environmental advantages by lowering the Portland cement clinker use. Accordingly, this is an opportunity to reduce carbon dioxide emissions and achieve net-zero carbon emissions by 2050. Furthermore, GBFS and CFA possess pozzolanic properties and enhance the mechanical strength and durability at later ages. Compressive strength and natural carbonation tests were performed in mortar and concrete. Cement-based materials made with GBFS and/or CFA presented a delay in the compressive strength development. In addition, they exhibited lower carbonation resistance than that of mortar and concrete made with plain Portland cements. Concrete reinforcement remains passive in common conditions; however, it could be corroded if the concrete pore solution pH drops due to the carbonation process. Service life estimation was performed for the ternary cements regarding the carbonation process. This information can be useful to material and civil engineers in designing concretes made with these ternary cements.

scholarly journals Granulated Blast-Furnace Slag and Coal Fly Ash Ternary Portland Cements Optimization

2020 ◽  
Vol 12 (14) ◽  
pp. 5783 ◽  
Author(s):  
Rosa Abnelia Rivera ◽  
Miguel Ángel Sanjuán ◽  
Domingo Alfonso Martín
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Coal Fly Ash ◽  
Cement Clinker ◽  
Portland Cements ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Granulated blast-furnace slag (GBFS) and coal fly ash (CFA) are two well-known constituents in Portland cements. Ternary Portland cements (GBFS-CFA-K) provide environmental advantages by reducing Portland cement clinker (K) production and, therefore, promote lower CO2 emissions. Nevertheless, both of them cause a delay in the compressive strength gain. Given that, the early compressive strength for both constituents is low, but they improve the compressive strength at medium and later ages as consequence of the pozzolanic reaction. In this paper, a full factorial design with two levels was developed for the mortar compressive strength estimation at 2, 7 and 28 days. Mortar prisms made with 25% and 40% of granulated blast-furnace slag (GBFS) and/or coal fly ash (CFA) were tested. The effects of the interaction between GBFS and CFA on the compressive strength development of ternary Portland cement mortars were reported. Results show that the contribution of both cement constituents to the ternary mortar mix reduces the compressive strength for all the tested ages. Nevertheless, the finer the GBFS, the better ternary cement performance was achieved, showing that the synergistic effect is more effective when the finer GBFS is used, probably due to a more adequate particle size distribution. Finally, a relationship between compressive strength, fineness, GBFS content and CFA content was found for each age.

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