scholarly journals Refractory and Mechanical Properties of Dealuminated Kaoline-Based Geopolymer Concrete

2020 ◽  
Vol 8 (5) ◽  
pp. 2045-2049
Keyword(s):  
Mechanical Properties ◽  
Refractory Concrete ◽  
Geopolymer Concrete ◽  
Thermal And Mechanical Properties ◽  
Concrete Mixtures ◽  
Cold Crushing Strength ◽  
Aluminous Cement ◽  
Shock Resistance ◽  
Alkaline Activator ◽  
Geopolymer Paste

This study has been performed to evaluate the performance of the industrial by-product dealuminated kaolin (DK) as geopolymer paste in production a refractory concrete. The paper study the thermal and mechanical properties of concrete mixtures containing crushed refractory brick as combined aggregate and geopolymer paste produced from the blend of 10%, 20% and 30% of DK, ordinary Portland cement (OPC), solution of sodium hydroxide and sodium silicate as alkaline activator. These concrete mixtures were tested for workability, shrinkage at 400,800 and 1200 °C, thermal shock resistance at temperature of 950 °C, Cold crushing strength, tensile strength, and elastic modulus. The results of these mixtures compared with the results of concrete mixtures containing 100% OPC and 100% aluminous cement (AC) .The results show that the thermal and mechanical properties of geopolymer concrete produced by dealuminated kaolin (DK) are enhanced. Also, it is found that mixture contains 20% of DK appears to be the optimal geopolymer concrete mixture.

scholarly journals Developing Geopolymer Concrete Properties by Using Nanomaterials and Steel Fibers

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
E. Rabiaa ◽  
R. A. S. Mohamed ◽  
W. H. Sofi ◽  
Taher A. Tawfik
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sodium Hydroxide ◽  
Steel Fiber ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Hardened Concrete ◽  
Geopolymer Concrete ◽  
Alkaline Activator ◽  
The Impact

This research investigates the simultaneous impact of two different types of steel fibers, nanometakaolin, and nanosilica on the mechanical properties of geopolymer concrete (GPC) mixes. To achieve this aim, different geopolymer concrete mixes were prepared. Firstly, with and without nanomaterials (nanosilica and nanometakaolin) of 0, 2%, 4%, 6%, and 8% from ground granulated blast furnace slag (GGBFS) were used. Secondly, steel fiber (hooked end and crimped) content of (0, 0.5%, 1, and 1.5%) was used. Thirdly, optimum values of nanomaterials with the optimum values of steel fiber were used. Crimped and hooked-end steel fibers were utilized with an aspect ratio of 60 and a length of 30 mm. Geopolymer mixes were manufactured by using a constant percentage of alkaline activator to binder proportion equal to 0.45 with GGBFS cured at ambient conditions. For alkaline activator, sodium hydroxide molar (NaOH) and sodium hydroxide solution (NaOH) were used according to a proportion (Na2SiO3/NaOH) of 2.33. The hardened concrete tests were performed through the usage of splitting tensile strength, flexural, and compressive experiments to determine the impact of steel fibers, nanometakaolin, and nanosilica individually and combined on performance of GPC specimens. The results illustrated that using a mix composed of the optimum steel fibers (1% content) accompanied by an optimum percentage of 6% nanometakaolin or 4% nanosilica demonstrated a significant enhancement in the mechanical properties of GPC specimens compared to all other mixtures. Besides, the impact of using nanomaterials individually was found to be predominant on compressive strength on GPC specimens especially with the usage of the optimum values. However, using nanomaterials individually compared to using the steel fibers individually was found to have approximately the same splitting tensile strength and flexural performance.

Thermal and Mechanical Properties of Plasma Sprayed ZrO2-CeO2-Y2O3 Coatings

1996 ◽  
Author(s):  
S. Sodeoka ◽  
M. Suzuki ◽  
T. Inoue ◽  
K. Ueno ◽  
S. Oki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Base Layer ◽  
Thermal Barrier ◽  
Thermal And Mechanical Properties ◽  
Stabilized Zirconia ◽  
Layered Coating ◽  
Barrier Coating ◽  
Shock Resistance ◽  
Plasma Sprayed

Abstract Plasma sprayed ZrO2-CeO2 and ZrO2-CeO2-Y2O3 coatings were investigated to develop advanced thermal barrier coating (TBC) with improved thermal and mechanical properties. The addition of a large amount of CeO2 to ZrO2 decreased the thermal conductivity, but it also reduced the mechanical property like hardness. Addition of Y2O3 to ZrO2-CeO2 was effective to improve the hardness. Double layered coating composed of a low thermal conductive top layer, such as ZrO2-CeO2-Y2O3 and a high strength base layer like yttria stabilized zirconia was fabricated. It exhibited an excellent thermal shock resistance and high thermal barrier capability.

Effect of Alkaline Activator Ratio to Mechanical Properties of Geopolymer Concrete with Trass as Filler

2015 ◽  
Vol 754-755 ◽  
pp. 406-412 ◽  
Author(s):  
Puput Risdanareni ◽  
Januarti Jaya Ekaputri ◽  
Mohd Mustafa Al Bakri Abdullah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Sodium Silicate ◽  
Setting Time ◽  
Geopolymer Concrete ◽  
Closed Porosity ◽  
Split Tensile Strength ◽  
Alkaline Activator ◽  
Test Result

This paper describes the effect of alkaline activator ratio (Na2SiO3/NaOH) to mechanical properties of geopolymer concrete. The mechanical properties of geopolymer concrete were assessed by setting time, split tensile strength and porosity. Fly ash was used as a cement substitute, and trass used as filler. While, Natrium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) was applied as alkaline activator. In this study, NaOH concentration eight and ten molar with an alkaline activator ratio Na2SiO3/ NaOH by mass: 0.5, 1, 1.5, 2 and 2.5 were used. The test result showed that setting time, porosity and split tensile strength of geopolymer concrete were hardly influenced by NaOH concentration and the alkaline activator ratio. The alkaline activator ratio of Na2SiO3/NaOH has an optimum value at 2 and 2.5. Test result showed that the fastest setting time was 25 minute, the highest amount of closed porosity was 9.035 % and the highest split tensile strength was 2.86 MPa.

scholarly journals Effect of Aggregate Types on the Mechanical Properties of Traditional Concrete and Geopolymer Concrete

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1110
Author(s):  
Hani Alanazi
Keyword(s):  
Mechanical Properties ◽  
Laser Scanning ◽  
Large Scale ◽  
Geopolymer Concrete ◽  
Coarse Aggregates ◽  
Concrete Mixtures ◽  
Different Types ◽  
Quartz Aggregates ◽  
Large Scale Tests ◽  
Physical And Chemical

For the same concrete quality, different types of coarse aggregates may result in different mechanical properties. This paper presents a study on the effect of aggregate types on the mechanical properties of two concretes, namely, geopolymer concrete (GP) and traditional Portland cement (TC) concrete. The mechanical properties were investigated through several large-scale tests. Moreover, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and laser scanning microscope (LSM) images were obtained to study the microstructure of tested mixes. The results revealed that the aggregate type has different effects on the mechanical properties of TC and GP, as they were behaving opposite to quartz and limestone aggregates. Microstructure analysis further confirmed the growth of well-bonded regions between the paste and aggregate in the GP with limestone aggregates, and the formation of several weak interfacial zones in concrete mixtures made with quartz aggregates. It was concluded that the mechanical properties of GP are very sensitive to the stiffness of aggregate, concentrations of stress, and the physical and chemical reactions occurring in the interfacial transition zone which may lead to improved or weakened bond strength between paste and aggregates.

Mechanical Properties of Volcanic Ash Based Geopolymer Concrete

2016 ◽  
Vol 857 ◽  
pp. 377-381 ◽  
Author(s):  
Puput Risdanareni ◽  
Adjib Karjanto ◽  
Januarti Jaya Ekaputri ◽  
Poppy Puspitasari ◽  
Febriano Khakim
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Research And Development ◽  
Volcanic Ash ◽  
Fresh Concrete ◽  
Geopolymer Concrete ◽  
Reconstruction Process ◽  
The World ◽  
Alkaline Activator

This paper presents the result of study on using volcanic ash which obtained from Mount Kelud as fly ash replacement material to produce geopolymer concrete. Test was conducted on geopolymer concrete mixture with 0%, 25%, 50% and 100% fly ash replacement with Kelud volcanic ash. Sodium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) were applied as alkaline activator. The mechanical properties was assessed by compressive strength while workability of fresh concrete by slump test. Producing geopolymer concrete with volcanic ash is possible with maximum replacement of up to 50%. Research and development on eco-friendly material such as volcanic ash is very useful to help reconstruction process of volcanic disaster around the world.

scholarly journals Development of High Strength Geopolymer Concrete using Nano Silica

2020 ◽  
Vol 10 (2) ◽  
pp. 73-80
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Cementitious Materials ◽  
Geopolymer Concrete ◽  
Nano Silica ◽  
Cement Production ◽  
Granulated Blast Furnace Slag ◽  
Alkaline Activator ◽  
Materials Used ◽  
Emission Of Greenhouse Gases

Cement production became responsible of polluting the atmosphere by the emission of greenhouse gases. This issue motivate the researchers to work hard to develop a new cementitious materials used in concrete having much lower foot print in environmental pollution. This paper presents the development of high strength geoploymer concrete using nano silica. Ground granulated blast furnace slag (GGBFS) is used as main cementitious material and silica fume (SF) is used as cement replacement by different ratios. The alkaline activator is used in different temperature and samples cured by different methods. Nano silica then added to the optimum geopolymer concrete sample by ratios 1, 2 and 3% of the total weight of cementitious materials. Samples tested for mechanical properties. The results showed that using hot activator and oven curing samples gives higher mechanical properties. Also using nano silica up to 2% increases the compressive strength up to 24% at age 28 days.

Mechanical and Fracture Characteristics of Refractory Concrete after the Action of Various Temperature Loading

2018 ◽  
Vol 760 ◽  
pp. 102-107
Author(s):  
Ondřej Holčapek
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Compressive Strength ◽  
Dynamic Modulus ◽  
Thermal Loading ◽  
Refractory Concrete ◽  
Fracture Characteristics ◽  
Residual Properties ◽  
Aluminous Cement ◽  
Refractory Composite

This article deals with the experimental investigation of residual mechanical properties of refractory composite after the action of various thermal loading. Specimens with dimension 40 × 40 × 160 mm were produced from composite containing basalt fibres and aggregate, aluminous cement and metakaolin. Different group of specimens were exposed to various temperatures 105 °C, 200 °C, 300 °C, 400 °C, 500 °C and 600 °C for three hours. Different temperature caused various changes in chemical composition of concrete that can result into decrease of mechanical properties. Bulk density, flexural strength, compressive strength, fracture energy and dynamic modulus of elasticity were investigated after each type of thermal loading. After the action of 600 °C all investigated residual properties achieved lowest values. Based on performed experiments we can conclude that the main decrease of mechanical properties take place after the action of 400 °C.

Mechanical and Thermal Properties

2016 ◽  
pp. 602-624
Author(s):  
Noémi S. Müller
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Material Properties ◽  
Thermal Shock Resistance ◽  
Test Methods ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Archaeological Ceramics ◽  
Shock Resistance ◽  
Manufacturing Parameters

This chapter provides an introduction to mechanical and thermal properties of archaeological ceramics, which are of importance for a ceramic’s affordances and affect its suitability to be used in different activities. An overview of thermal and mechanical properties, namely fracture strength and fracture energy (toughness), thermal shock resistance and thermal conductivity, is provided, outlining the underlying principles of these properties and test methods typically used to measure them. Emphasizing the importance of potter’s choices during manufacture on the finished products’ material properties, the influence of different manufacturing parameters, in particular firing and tempering strategies, is discussed and underlying principles and mechanisms, which are applicable to a wide variety of commonly encountered archaeological ceramics, are elucidated.

Performances of Artificial Lightweight Geopolymer Aggregate (ALGA) in OPC Concrete

2016 ◽  
Vol 673 ◽  
pp. 29-35 ◽  
Author(s):  
R.A. Razak ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Khairul Nizar Ismail ◽  
D. Hardjito ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
High Volume ◽  
Alkaline Activator ◽  
Geopolymer Paste

The non-availability of natural lightweight aggregate and demand are increasing in worldwide, thus new alternatives on producing artificial aggregate should be developed. This paper discussed on the mechanical properties of artificial lightweight geopolymer aggregate (ALGA) made from LUSI mud and alkaline activator in concrete. LUSI means Sidoarjo mud from Indonesia which erupted on 2006 with high volume and impacted an area of almost 770 hectare. The alkaline activator used was combination of sodium hydroxide and sodium silicate. The geopolymer paste formed need to be pelleted and sintered at 950 °C. The results showed that the compressive strength of OPC-ALGA concrete is 41.89 MPa at 28 days of testing with a density of 1760.1 kg/m3 which can be classified as lightweight concrete. The water absorption of ALGA concrete is 2.77%.

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