scholarly journals Investigation of Erosion of Cement-Bentonite via Piping

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Zijun Wang ◽  
Boming Zhao ◽  
A. C. D. Royal
Keyword(s):  
Blast Furnace Slag ◽  
Cementitious Materials ◽  
Water Erosion ◽  
Granulated Blast Furnace Slag ◽  
Curing Period ◽  
Erosion Test ◽  
Materials Used ◽  
Mathematical Relationships ◽  
Seepage Barriers ◽  
Furnace Slag

Cement-bentonite is one of the main materials used in the seepage barriers to protect earth dams and levees from water erosion. However, the current understanding of the erodibility of the cementitious materials and the interactions between cracked seepage barriers and the water flow is inadequate. Based on the laboratory pinhole erosion test, we first investigated the impacts of cement-bentonite treatments by using the ground granulated blast-furnace slag (GGBS) as replacement on the erosion characteristics, compared with the original mixtures; the inclusion of GGBS highlighted a potential advantage against water erosion. In addition, we proposed to calculate the erosion percentage and establish the mathematical relationships between the erosion percentage and different regimes, that is, different curing period, erosion time, and sizes of initial holes. Results showed that enough curing period was critical to avoid the increases of hydraulic conductivity in the macrofabric of the barrier; meanwhile, the materials were eroded quickly at the beginning and slowed down with the erosion time, where the enlargement of the initial creaks would be stabilised at some point in time. Moreover, the sizes of initial holes may affect the erosion situation varying from the sample curing periods.

scholarly journals Synergistic Excitation Mechanism of CaO-SiO2-Al2O3-SO3 Quaternary Active Cementitious System

2021 ◽  
Vol 8 ◽  
Author(s):  
Fusheng Niu ◽  
Yukun An ◽  
Jinxia Zhang ◽  
Wen Chen ◽  
Shengtao He
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Test Block ◽  
Hydration Reaction ◽  
Alkaline Environment ◽  
Granulated Blast Furnace Slag ◽  
Cementitious System ◽  
Furnace Slag

In this study, the influence of steel slag (SS) content on the strength of the cementitious materials was investigated. The quaternary active cementitious material (CaO-SiO2-Al2O3-SO3) was prepared using various proportions of steel slag (SS), granulated blast furnace slag (BFS), and desulfurized gypsum (DG). The mechanism of synergistic excitation hydration of the cementitious materials was examined using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The strength of the mortar test block was initially increased and decreased later with the increase of the SS content. Mortar test block with 20% steel slag, 65% granulated blast furnace slag, and 15% desulfurized gypsum with 0.35 water-binder ratio showed the highest compressive strength of 57.3 MPa on 28 days. The free calcium oxide (f-CaO) in the SS reacted with water and produced calcium hydroxide (Ca(OH)2) which created an alkaline environment. Under the alkaline environment, the alkali-activated reaction occurred with BFS. In the early stage of hydration reaction, calcium silicate hydrate (C-S-H) gel and fibrous hydration product ettringite (AFt) crystals were formed, which provided early strength to the cementitious materials. As the hydration reaction progressed, the interlocked growth of C-S-H gel and AFt crystals continued and promoted the increase of the strength of the cementitious system.

Effect of Aggregate Max Size on the Rheological Properties of Self Consolidating Concrete

2020 ◽  
Vol 853 ◽  
pp. 193-197
Author(s):  
Samer Al Martini ◽  
Ziad Hassan ◽  
Ahmad Khartabil
Keyword(s):  
Blast Furnace Slag ◽  
Aggregate Size ◽  
Maximum Size ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Self Consolidating Concrete ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Time Period ◽  
Furnace Slag

The effects of aggregate size and supplementary cementitious materials (SCMs) on the rheology of self-consolidating concrete (SCC) were studied in this paper. Two main concrete mixtures with different maximum aggregate sizes were prepared and investigated. The first mix had a maximum size aggregate of 5 mm and the second mix was with 20 mm max size aggregates. All mixes incorporated different dosages of Ground granulated blast furnace slag (GGBS). The rheology of all mixes investigated was measured over 2 hour time period. It was found that the size of aggregates and GGBS dosage have influence on the yield stress of studied concrete mixes.

scholarly journals Characterization of Supplementary Cementitious Materials and Fibers to Be Implemented in High Temperature Concretes for Thermal Energy Storage (TES) Application

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5190
Author(s):  
Laura Boquera ◽  
David Pons ◽  
Ana Inés Fernández ◽  
Luisa F. Cabeza
Keyword(s):  
Tensile Strength ◽  
Blast Furnace ◽  
High Temperature ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Iron Silicate ◽  
Supplementary Cementitious Materials ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Six supplementary cementitious materials (SCMs) were identified to be incorporated in concrete exposed to high-temperature cycling conditions within the thermal energy storage literature. The selected SCMs are bauxite, chamotte, ground granulated blast furnace slag, iron silicate, silica fume, and steel slag. A microstructural characterization was carried out through an optical microscope, X-ray diffraction analysis, and FT-IR. Also, a pozzolanic test was performed to study the reaction of SCMs silico-aluminous components. The formation of calcium silica hydrate was observed in all SCMs pozzolanic test. Steel slag, iron silicate, and ground granulated blast furnace slag required further milling to enhance cement reaction. Moreover, the tensile strength of three fibers (polypropylene, steel, and glass fibers) was tested after exposure to an alkalinity environment at ambient temperature during one and three months. Results show an alkaline environment entails a tensile strength decrease in polypropylene and steel fibers, leading to corrosion in the later ones.

scholarly journals Performa Beton Dengan Ground Granulated Blast Furnace Slag Terhadap Sulfate Attack

2020 ◽  
Vol 16 (3) ◽  
pp. 185
Author(s):  
Rizki Amalia Tri Cahyani ◽  
Ernawan Setyono ◽  
Yunan Rusdianto
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Serangan sulfat (sulfate attack) termasuk hal yang umum terjadi pada struktur beton, mengingat ion sulfat banyak dijumpai pada tanah, air tanah dan air laut. Peningkatan ketahanan beton melawan sulfat akan berdampak besar pada durabilitas dan umur layan struktur beton. Penambahan supplementary cementitious materials seperti GGBFS (ground granulated blast furnace slag) ke campuran beton telah terbukti memberikan pengaruh positif terhadap durabilitas dan properti mekanis beton. Namun, GGBFS tergolong material yang baru dikembangkan di Indonesia dan potensinya dalam meningkatkan durabilitas beton belum dimanfaatkan secara luas. Berdasarkan hal tersebut, perlu dilakukan investigasi terkait aplikasi GGBFS dan pengaruhnya terhadap durabilitas beton, terutama dalam melawan serangan sulfat. Dalam studi ini, durabilitas beton dengan persentase penggantian GGBFS 30%, 50% dan 70% terhadap total volume binder dievaluasi menggunakan perlakuan siklus basah-kering dalam larutan magnesium sulfat. Tingkat degradasi beton diukur dengan melakukan observasi terhadap perubahan kuat tekan dan massa spesimen akibat serangan sulfat. Hasil penelitian menunjukkan bahwa penggantian GGBFS hingga 50% dari total volume binder dapat meningkatkan ketahanan beton terhadap serangan sulfat, ditunjukkan dengan kehilangan massa dan reduksi kekuatan yang lebih rendah dibandingkan spesimen kontrol dengan 100% semen Portland.

Durability of Normal and Lightweight Aggregate Mortars with Different Supplementary Cementitious Materials

2021 ◽  
Vol 17 ◽  
pp. 271-281
Author(s):  
Efstratios Badogiannis ◽  
Eirhnh Makrinou ◽  
Marianna Fount
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Lightweight Aggregate ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Pumice Sand ◽  
Water To Binder Ratio ◽  
Furnace Slag

A study on the durability parameters of normal and lightweight aggregate mortars, incorporated different supplementary cementitious materials (SCM) is presented. Mortars were prepared using limestone or pumice as aggregates and Metakaolin, Fly ash, Granulated Blast Furnace Slag and Silica Fume, as SCM, that they replaced cement, at 10 % by mass. Ten different mortars, having same water to binder ratio and aggregate to cement volumetric ratio, they were compared mainly in terms of durability. The use of pumice sand was proved to be effective not only to the density of the mortars as it was expected, but also in durability, fulfilling at the same time minimum strength requirements. The addition of the different SCM further enhanced the durability of the mortars, where Metakaolin was found to be the most effective one, especially against chloride’s ingress.

Effect of Using Ground Granulated Blast Furnace Slag in Rigid Pavement Overlays

2022 ◽  
Vol 1048 ◽  
pp. 396-402
Author(s):  
H.C. Guruprasad ◽  
R. Sridhar ◽  
R. Ravi Kumar
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Cost Effective ◽  
Normal Concrete ◽  
Rigid Pavement ◽  
Granulated Blast Furnace Slag ◽  
Curing Period ◽  
Iron Manufacturing ◽  
Pozzolanic Properties ◽  
Furnace Slag

Cement is replaced with Ground Granulated Blast Furnace Slag (GGBS), to produce a cost effective concrete and to gain effective compressive strength. It is produced in iron manufacturing industries. It has pozzolanic properties and has particle size less than 90μ. In this experimental study, cubes of size 150×150×150 mm and cylinders of 150 mm dia and 300 mm height were casted byreplacing GGBS from dosage of 8% up to 65% for curing period of 7days, 14days, 28days and 56days for M 40 grade concrete. Also, Alccofines were added in addition in varying percentage of 3%, 6%, 9% and 12% in order to gain high early strength and increase the workability. Hyper-Plasticizers were also added in order to reduce the water-content of the concrete. The results of GGBSCC were compared with that of normal concrete results.

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