scholarly journals Aplikasi Response Surface Methodology pada Optimasi Penambahan Blast Furnace Slag Terhadap Waktu Pengikatan dan Kuat Tekan Semen

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.

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.


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).


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.


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.


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.


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.


2014 ◽  
Vol 578-579 ◽  
pp. 1430-1440 ◽  
Author(s):  
Joon Woo Park ◽  
Sung In Hong ◽  
Hee Jun Yang ◽  
Thamara Tofeti Lima ◽  
Ki Yong Ann

The present study concerns a development of cement-free concrete using ground granulated blast-furnace slag (GGBS) with alkali-activators such as KOH, NaOH, and Ca (OH)2. To find out the development among three different activators, the concentration of hydroxyl ion was kept 0.5%, 1.0%, 1.5%, 2.0% and 3.0% by weight of binder irrespective of cations. The setting time was measured by penetration resistance immediately after casting of mortar. The development of compressive strength was measured at 7, 14, 28, and 91 days. The pore structure of cement-free mortar was examined by the mercury intrusion porosimetry (MIP) and rapid chloride penetration test (RCPT). Simultaneously, grew sample was used to microscopically observe at the XRD. For strength of cement-free mortar, mixed with KOH or NaOH was as high as OPC at 3.0 % by weight of binder. However, the compressive strength of cement-free concrete mixed with 3.0 % Ca (OH)2 by weight of binder had just half strength of OPC mortar. Cement-free concrete activated with NaOH and Ca (OH)2 had higher total pore volume, however, it had lower ionic penetrability due to the pore type which mostly consist of gel pores. For pore structure of cement-free mortar mixed with KOH, the total volume had similarity to that of OPC mortar, however, it had lower penetrability. Therefore, it may have higher resistance to chloride transport than that of OPC mortar.


2019 ◽  
Vol 12 (2) ◽  
pp. 101
Author(s):  
Tri Septa A.D., Qomariah, Akhmad Suryadi

The use of steel smelting waste industry is used to reduce the waste overflow at the site. The waste steel smelting industry called blast furnace slag (BFS) used as a substitution for cement in a concrete mixture in a Laboratory Material Test, Civil Engineering State Polytechnic of Malang. The purpose of this analysis is to: 1) Test the workability of normal concrete and concrete with BFS; 2) Find out compressive strength of each concrete; 3) Compare the price to both concrete in the construction of building.The required data were of gradation of aggregate, water content of aggregate, density of aggregate, absorption of aggregate, bulk density of aggregate, fineness of cement, normal consistency of cement, cement setting time, compressive strength of mortar cement, and the price of building materials Surabaya 2016. SNI 03-2834-2000 method was applied with variations BFS substitute of cement are 0%, 10%, 15%, 20%, and 30% BFS and the planned compressive strength obtained at 28 days of 300 kg/cm2.The analyses result in 1) The workability of each concrete: 5.75cm of normal concrete (0%), 3.45cm, 3.15cm, 3.1cm, and 3.05cm respectively with BFS concrete; 2) The compressive strength of each concrete at 28 days: 235.56kg/cm2 of normal concrete, 105.33kg/cm2, 138.96kg/cm2, 127.26kg/cm2, and 94.52kg/cm2respectively with BFS concrete; The use of BFS cannot be applied to the concrete mixture, because of low compressive strength; 3) For the price of concrete materials per m3 are IDR 999.472,05 of normal concrete, IDR 996.926,78 for 10% with BFS, IDR 995.654,93 for 15% with BFS, IDR 994.381,50 for 20% with BFS, and IDR 991.837,80 for 30% with BFS. Keywords: BFS, workability, compressive strength


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