scholarly journals Incorporation of Cement Bypass Dust in Hydraulic Road Binder

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 41
Author(s):  
Nadezda Stevulova ◽  
Julius Strigac ◽  
Jozef Junak ◽  
Eva Terpakova ◽  
Marian Holub

This article describes utilization of a cement kiln bypass dust utilization as an added component in a hydraulic road binder. Three experimental binder mixes (BM1–BM3) with variation in the composition of the main constituents (cement clinker, ground limestone and ground granulated blast furnace slag) and constant content of bypass dust (10%) were prepared under laboratory conditions. The properties of binder constituents, fresh experimental binder mixes and hardened specimens were tested according to STN EN 13282-2 for a normal hardening hydraulic road binder. The physical and chemical properties of all binder mixes (fineness: +90 µm ≤ 15 wt.%; SO3 content: <4 wt.%) met the standard requirements. The bypass dust addition led to an increase in the water content for standard consistency of cement mixes (w/c = 0.23) and to a shortening of the initial setting time for two experimental blended cement pastes (BM1 and BM3) compared with the value required by the standard. Only BM2 with the lowest SO3 content (0.363 wt.%) and the highest percentage of granulated blast furnace slag (9.5 wt.%) and alkalis (Na2O and K2O content of 5.9 wt.%) in the binder mix met the standard value for the initial setting time (≥150 min). The results of compressive strength testing of experimental specimens after 56 days of hardening (59.2–63.9 MPa) indicate higher values than the upper limit of the standard requirement for the N4 class (≥32.5; ≤52.5 MPa).

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1287
Author(s):  
Marek Kovac ◽  
Alena Sicakova ◽  
Matej Spak

The article deals with cement supplementary materials based on ground granulated blast furnace slag and zeolite. Purpose of the experiment was to observe dependences (if they exist) between selected parameters (modulus of basicity, modulus of hydraulicity and initial setting time) and activity indexes, for easier and quicker way to determine or predict the activity index. Testing showed that moderate dependences between those parameters and activity indexes were observed. Results showed that prediction of activity indexes based on chemical composition is feasible.


Author(s):  
Ahmed Zeraoui ◽  
Walid Maherzi ◽  
Mahfoud Benzerzour ◽  
Nor-Edine Abriak

CO2 emissions resulting from the production of cement is a major issue, but can be limited by the partial substitution of cement by low-carbon-impact additions. The aim of this study was the formulation of a ternary binder based on ordinary Portland cement (OPC), ground granulated blast-furnace slag (GGBS) and flash-calcined sediment (FCS), a dredged waste which was valorized after applying a new heat treatment: flash calcination. The used materials were physically, chemically and mineralogically characterized. The composition of the formulations was optimized using mixture designs. Five formulations, one reference formulation RM (100% OPC), one binary formulation (50% OPC/50% GGBS), and three ternary formulations with a variable FCS rate (10%, 15%, 20%), were selected and characterized fresh and hardened. Results showed that the incorporation of FCS reduced the workability and increased the density. In addition, a decrease in the initial setting time and the heat of hydration peak were observed. In the hardened state, the formulation containing 10% FCS showed 90-day mechanical strengths superior to that of RM. The use of FCS in ternary binders could reduce the environmental impact by reducing greenhouse gas emissions.


2020 ◽  
Vol 4 (1) ◽  
pp. 61
Author(s):  
Hardjono Hardjono ◽  
Cucuk Evi Lusiani ◽  
Agung Ari Wibowo ◽  
Mochammad Agung Indra Iswara

Produksi semen setengah jadi (clinker) membutuhkan energi yang tinggi sehingga menggunakan batu bara dalam jumlah besar. Hal ini menyebabkan biaya produksi dari pabrik semen juga tinggi. Kebutuhan energi yang besar untuk menghasilkan clinker tersebut dapat dikurangi dengan menambahan blast furnace slag sebagai campuran pembuatan semen. Campuran clinker dapat menghasilkan produk semen yang memiliki waktu pengikatan dan kuat tekan sesuai SNI. Pengaruh penambahan blast furnace slag sebagai campuran clinker terhadap waktu pengikatan dan kuat tekan semen dapat dioptimalkan dengan response surface methodology (RSM) menggunakan Central Composite Design (CCD). Optimasi dengan menggunakan RSM bertujuan untuk mengetahui kondisi optimum pada penambahan blast furnace slag dan clinker terhadap variabel respon berupa waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Hasil uji ANOVA dan analisis response surface menunjukkan bahwa penambahan blast furnace slag sebagai campuran dalam pembuatan semen memberikan pengaruh yang signifikan terhadap waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Penambahan 5% blast furnace slag dengan 92,5% clinker pada campuran clinker dan gypsum merupakan kondisi optimum yang memberikan pengaruh signifikan terhadap variabel respon.The production of clinker consumes high energy and causes high production cost of cement industry. It can be reduced by adding blast furnace slag as a mixture in cement production. The blast furnace slag - clinker mixture can produce cement with setting time and compressive strength according to SNI. The effect of the addition of blast furnace slag as a clinker mixture to the setting time and compressive strength of cement can be optimized by response surface methodology (RSM) using Central Composite Design (CCD). Optimization by using RSM aims to determine the optimum condition of the blast furnace slag – clinker mixture to the initial setting time, final setting time, and compressive strength. ANOVA test results and response surface analysis show that the addition of blast furnace slag into the cement mixture has a significant influence on the initial setting time, final setting time, and compressive strength. The addition of  5% blast furnace slag with  92.5% clinker in the mixture of clinker and gypsum is the optimum condition which gives a significant effect on the response variable.


2013 ◽  
Vol 12 (3) ◽  
pp. 215-222
Author(s):  
Katarzyna Synowiec

The paper presents the tests results of the properties of non - standard fly ash - slag cements composition. Both natural (unprocessed) and activated by grinding calcareous fly ash was used. It was found that the calcareous fly ash next to the granulated blast furnace slag may be a component of low - clinker cements (ca. 40%). Those cements are characterized by low heat of hydration and overdue of initial setting time in comparison with Ordinary Portland Cement, moreover they have an unfavorable effect on consistency and its upkeep in time. Production of fly ash - slag cements is possible for strength class 32,5 N when the component of cement is raw fly ash, and for strength classes 32,5 N, 32,5 R and 42,5 N when ground fly ash was used. Fly ash activated by grinding was characterized by higher activity.


2015 ◽  
Vol 244 ◽  
pp. 94-101 ◽  
Author(s):  
Pavel Mec ◽  
Jana Boháčová ◽  
Josef Koňařík ◽  
Petr Závrský

Alkali-activated systems, formed by the alkaline activation are inorganic materials characterized by the potential of ecological use. The objective of experiment was to investigate the influence of different activators on selected properties of alkali-activated systems based on granulated blast furnace slag. At the beginning of the experiment, 21 different samples prepared of 12 types of activators were tested to the basic properties. Then, selected samples with the best potencial to use were tested to compressive and flexural strength, frost resistance and surface resistance to chemical de-icing substances. The initial setting time achieved 25 - 95 minutes and final setting time achieved 30 - 105 minutes, compressive strengths were in the range 40 - 100MPa, frost resistance and resistance of surface to water and defrosting chemicals were confirmed.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 382 ◽  
Author(s):  
Danying Gao ◽  
Zhenqing Zhang ◽  
Yang Meng ◽  
Jiyu Tang ◽  
Lin Yang

This work aims to investigate the effect of additional flue gas desulfurization gypsum (FGDG) on the properties of calcium sulfoaluminate cement (CSAC) blended with ground granulated blast furnace slag (GGBFS). The hydration rate, setting time, mechanical strength, pore structure and hydration products of the CSAC-GGBFS mixture containing FGDG were investigated systematically. The results show that the addition of FGDG promotes the hydration of the CSAC-GGBFS mixture and improves its mechanical strength; however, the FGDG content should not exceed 6%.


2018 ◽  
Vol 149 ◽  
pp. 01012 ◽  
Author(s):  
Leonid Dvorkin ◽  
Nataliya Lushnikova ◽  
Mohammed Sonebi

The increase of the consumption of gypsum products in construction industry with a limited amount of natural gypsum deposits requires alternative sources of gypsum-containing raw materials. In some countries which have fertilizers industry plants, the problem can be solved using industrial wastes, e.g. phosphorgypsum – a byproduct of fertilizers’ production. Kept in dumps over decades, phosphorgypsum is subjected to the chemical changes due to washing out impurities with rain and other natural factors. However, there are observed deviations of harmful impurities in dumped PG depending on its age., Phosphorgypsum of any age requires chemical treatment to neutralize remains of phosphorus and sulfuric acids, fluorine compounds. According to our researches one of the most simple and effective method of neutralization the impurities is using lime-containing admixtures. The paper presents results of laboratory tests of phosphorgypsum as a component of clinker and non-clinker binders. There were investigated the impact of phosphorgypsum as admixture for clinker binders to substitute natural gypsum. Neutralized phosphorgypsum can be applied as mineralizing admixture in calcination of Portland cement clinker. Adding 2 to 2.5% of phosphorgypsum as setting time regulator resulted in a similar physical and mechanical properties compared to mix made with natural gypsum. Another important area of phosphorgypsum application is sulphate activatoion of low-clinker blast-furnace slag cement (clinker content is less than 19%). According to results, the incorporation of phosphorgypsum as sulphate activator in cement has the better effect as natural gypsum. Other development has been carried out to modify the phosphorgypsum binder properties. Complex additive consisted of polycarboxylate-based superplasticizer and slaked lime permitted an increase mechanical properties of hardened phosphorgypsum binder due to significant a reduction of water consumption. Such modified binder can be used as partial or complete replacement of gypsum binder for filling cements and finishing plasters. It can substitute gypsum in non-clinker binders like supersulphated cements. There were also developed compositions of supersulphated cements based on low-alumina blast furnace slag and phosphorgypsum. Supersulphated cements were tested in normal-weight and light-weight concrete.


Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 443
Author(s):  
Selma Bellara ◽  
Mustapha Hidjeb ◽  
Walid Maherzi ◽  
Salim Mezazigh ◽  
Ahmed Senouci

This study investigated the potential use of Zerdezas dam Calcined Sediments (CS) and El-Hadjar Blast Furnace Slag (GGBS) from northern Algeria as a partial replacement of cement (C) in normal hardening hydraulic road binders. Two binder mix designs were optimized using a Response Surface Methodology (RSM). The first mix, 50C35GGBS15CS, consisted of 50% cement, 35% blast furnace slag, and 15% calcined sediment. The second mix, 80C10GGBS10CS, consisted of 80% cement, 10% blast furnace slag, and 10% calcined sediments. The tests of workability, setting time, volume expansion, compressive and flexural strengths, porosity, and SEM were conducted to ensure that both mixes meet the standard requirements for road construction binders. The two proposed mixes were qualified as normal hardening hydraulic road binder. The reuse of the sediments will contribute to a better disposal of dam sediments and steel industry waste and to preserve natural resources that are used for manufacturing cement. It will also contribute to the environmental impact reduction of cement clinker production by reducing greenhouse gas emissions.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  

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.


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