Middle stage of Portland cement hydration influenced by different portions of silica fume, metakaolin and ground granulated blast-furnace slag

2019 ◽  
Vol 138 (6) ◽  
pp. 4119-4126 ◽  
Author(s):  
Eva Kuzielová ◽  
Matúš Žemlička ◽  
Radoslav Novotný ◽  
Martin T. Palou
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Cement Hydration ◽  
Middle Stage ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Portland Cement Hydration

scholarly journals Use of Slag from the Combustion of Solid Municipal Waste as A Partial Replacement of Cement in Mortar and Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1593
Author(s):  
Monika Czop ◽  
Beata Łaźniewska-Piekarczyk
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Municipal Solid Waste ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additives ◽  
Furnace Slag

In Europe, the use of wastes in the cement and construction industry follows the assumptions of sustainability and the idea of circular economy. At present, it is observed that cement plants introduce wastes to the cement in the form of so-called mineral additives. The most often used mineral additives are: fly ash with silica fume, granulated blast furnace slag and silica fume. The use of mineral additives in the cement is related to the fact that the use of the most expensive component of cement—Portland cement clinker—is limited. The purpose of the article is a preliminary evaluation of the suitability of slag from the municipal solid waste incineration plant for its use as a replacement of cement. In this article, slag from the municipal solid waste incineration (MSWI) replaces cement in the quantity of 30%, and presents the content of oxides and elements of slag from the MSWI. The obtained results are compared to the requirements that the crushed and granulated blast furnace slag need to meet to be suitable for use as an additive of type II to the concrete. The conducted analyses confirmed that the tested slag meets the requirements for the granulated blast furnace slag as an additive to the concrete in the following parameters: CaO ≤ 18.0%, SO3 ≤ 2.5% and Cl ≤ 0.1%. At the same time, mechanical features were tested of the designed mortars which consisted of a mixture of Portland cement (CEM I) with 30% of slag admixture. The designed mortar after 28 days of maturing reached a compressive strength of 32.0 MPa, and bending strength of 4.0 MPa. When compared to the milled granulated blast furnace slag (GBFS), the obtained values are slightly lower. Furthermore, the hardened mortars were subject to a leachability test to check the impact on the environment. Test results showed that the aqueous extracts from mixtures with 30% of slag admixtures slightly exceed the limits and do not pose a sufficiant threat to the environment as to eliminate the MSWI slag from economical use.

The Durability of Partially-Damaged Concrete with the Addition of Silica Fume and Ground Granulated Blast Furnace Slag

2016 ◽  
Vol 711 ◽  
pp. 277-284 ◽  
Author(s):  
Walid A. Al-Kutti ◽  
Nabil M. Al-Akhras
Keyword(s):  
Electrical Resistivity ◽  
Blast Furnace ◽  
Portland Cement ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Concrete Durability ◽  
Chloride Permeability ◽  
Granulated Blast Furnace Slag ◽  
Strength Capacity ◽  
Furnace Slag

This study investigates the durability of partially-damaged concrete with the addition of Silica Fume and Ground Granulated Blast Furnace Slag. Portland cement was replaced by 10% SF and 60% of GGBFS as a replacement of Portland cement. Thirty-six concrete cylinders (100 x 200 mm) were subjected to three compressive loading levels (50%, 75%, and 90% of its ultimate strength capacity). After 28 days of curing, the concrete specimens were experimentally tested for electrical resistivity, rapid chloride penetration (RCPT) and chloride migration coefficient (Dnssm) according to NT-BUILD 494. The experimental results showed that the GGBFS improves significantly the durability of concrete with the highest electrical resistivity and lowest chloride permeability compared to control and SF concrete and both SF and GGBFS had significant effect the concrete durability properties even when the concrete was subjected to compressive damage up to 90% of the compressive strength. A correlation between Dnssm and RCPT in partially damaged concrete was observed and an empirical linear relationship was developed to estimate Dnssm.

scholarly journals Protective Geopolymer Coatings Containing Multi-Componential Precursors: Preparation and Basic Properties Characterization

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Adhesive Strength ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Rapid Test ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper presents an experimental investigation on geopolymer coatings (GPC) in terms of surface protection of civil structures. The GPC mixtures were prepared with a quadruple precursor simultaneously containing fly ash (FA), ground granulated blast-furnace slag (GBFS), metakaolin (MK), and Portland cement (OPC). Setting time, compressive along with adhesive strength and permeability, were tested and interpreted from a perspective of potential applications. The preferred GPC with favorable setting time (not shorter than 120 min) and desirable compressive strength (not lower than 35 MPa) was selected from 85 mixture formulations. The results indicate that balancing strength and setting behavior is viable with the aid of the multi-componential precursor and the mixture design based on total molar ratios of key oxides or chemical elements. Adhesive strength of the optimized GPC mixtures was ranged from 1.5 to 3.4 MPa. The induced charge passed based on a rapid test of coated concrete specimens with the preferred GPC was 30% lower than that of the uncoated ones. Setting time of GPC was positively correlated with η[Si/(Na+Al)]. An abrupt increase of setting time occurred when the molar ratio was greater than 1.1. Compressive strength of GPC was positively affected by mass contents of ground granulated blast furnace slag, metakaolin and ordinary Portland cement, and was negatively affected by mass content of fly ash, respectively. Sustained seawater immersion impaired the strength of GPC to a negligible extent. Overall, GPC potentially serves a double purpose of satisfying the usage requirements and achieving a cleaner future.

scholarly journals Fine ground granulated blast furnace slag for saving quantity of binder

2019 ◽  
Vol 110 ◽  
pp. 01055
Author(s):  
Liliya Kazanskaya ◽  
Nicolay Privalov ◽  
Svetlana Privalova
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Mineralogical Composition ◽  
High Specific Surface Area ◽  
Resource Saving ◽  
Water Reduction ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additives ◽  
Furnace Slag

Nowadays, it is acknowledged that the use of mineral additives based on ground slag is one of ways of resource saving and improvement of technical properties of cement composites. Mineral additives with fineness similar to the Portland cement fineness are often used to replace part of Portland cement. Two kinds of ultra-fine ground granulated blast furnace slag that differ in composition and fineness were studied in the paper. Water-reduction due to effect of super plasticizer in slag-Portland cement compositions with amount of slag up to 70% was studied. The results of reduction of binder quantity per 1 kg of chemical admixture due to significant water-reduction are obtained and analysed. Correlations depending on kind, amount and fineness of slags, as well as depending on mineralogical composition of Portland cement were stated. The ultra-fine mineral additives based on ground slag with high specific surface area can be used for significant reduction of compositional binder.

Alkali Activation of Granulated Blast Furnace Slag

2010 ◽  
Vol 158 ◽  
pp. 1-11 ◽  
Author(s):  
Zi Qiao Jin ◽  
Xian Jun Lu ◽  
Shu Gang Hu
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Ordinary Portland Cement ◽  
Hydration Product ◽  
Early Age ◽  
Hydration Products ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

In order to stimulate the potential cementitious property of granulated blast furnace slag (GBFS), the ground GBFS sample (Wei Fang Iron and Steel Corporation, China) was activated by lime and gypsum under different dosages. The results showed that lime is an effective activator for the slag, and the optimum dosage of lime is about 10% (w/w) of the slag. At the optimum dosage of lime, the 28 days compressive strength of the lime-slag paste is higher than that of 32.5 ordinary Portland cement (OPC). But, the early age strength (3 and 7 days compressive strength) of the lime-slag paste is lower than that of the OPC. Addition of gypsum can effectively improve the early age strength of the lime-slag paste. At the ratio of gypsum:lime:slag of 8.2:9.2:82.6 (w/w), both the early and long-term compressive strengths of the gypsum-lime-slag paste are higher than that of the OPC. According to XRD, TG-DTA and SEM detections of the hydration products of the lime-slag paste, the gypsum-lime-slag paste and the OPC paste, it reveals that the hydration process of the GBFS-based cementitious material is different from the ordinary Portland cement and the presence of ettringite (AFt) contributes to the early age strength of the pastes. The major hydration product of the OPC paste (<7 days) were measured as ettringite (AFt), but the AFt phase was not detected in the hydration product of the lime-slag paste and the major hydration product of the lime-slag paste was determined as amorphous CSH gel. However, AFt was detected in the hydration products of the gypsum-lime-slag paste in the early stages of hydration, and the formation of AFt is favorable for the early strength improvement of the material.

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