Development of high strength Sustainable E-Waste concrete

2021 ◽  
Author(s):  
G Lalitha
Keyword(s):  
High Strength ◽  
Waste Concrete

Effect of F-S Mineralizer on the Calcination of Recycled Cement Clinker Produced from Waste Concrete

2016 ◽  
Vol 680 ◽  
pp. 435-438
Author(s):  
Hong Mei Ai ◽  
Su Feng Zhu ◽  
Xiao Qing Liu
Keyword(s):  
Cement Paste ◽  
Raw Materials ◽  
Value Added ◽  
High Strength ◽  
Silica Content ◽  
Cement Clinker ◽  
Fine Aggregate ◽  
Silicate Mineral ◽  
Waste Concrete ◽  
Strength Minerals

The recycled cement production, utilizing all components of the waste concrete without separation treatment as raw materials, provides an effective method for the high value-added resource recovery of waste concrete. However, as fine aggregate (sand) is the main siliceous component in the recycled cement raw materials prepared from waste concrete, its excessive high-crystalline silica content negatively impacts the burnability of raw meal and the property of clinker. By comparing and analyzing the results of burnability test, XRD patterns of clinker and compression strengths of cement paste, this paper attempts to explore the effect of F-S mineralizer on the calcination of recycled cement clinker produced from waste concrete. It could be concluded that F-S mineralizer has a significant improvement on the burnability of recycled cement raw meal, and the f-CaO content decreases with the mineralizer dosage rising. Moreover, in the case of calcination temperature at 1350°C, F-S mineralizer contributes to the enhancement of compression strength of recycled cement paste. Early high-strength minerals ( and C11A7⋅CaF2) are prime motivator to early strength increment, while long-term strength benefits from mineralizer’s improving on hydration activity of silicate mineral in clinker.

scholarly journals Preparation of High Strength Geopolymer Hardened Material from Waste Concrete

2012 ◽  
Vol 59 (3) ◽  
pp. 137-140 ◽  
Author(s):  
Teruhisa HONGO ◽  
Kan IGARASHI ◽  
Atsushi IIZUKA ◽  
Akihiro YAMASAKI
Keyword(s):  
High Strength ◽  
Waste Concrete

scholarly journals Mechanical Properties of High Strength Mortars Made withFine Waste Concrete Aggregates and Ground Granulated Blast Furnace Slag

2018 ◽  
Vol 26 (2) ◽  
pp. 338-355
Author(s):  
Ali Hassoon Nahhab
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Concrete Aggregate ◽  
Natural Sand ◽  
Concrete Aggregates ◽  
Granulated Blast Furnace Slag ◽  
Waste Concrete ◽  
Experimental Findings ◽  
Furnace Slag ◽  
Different Levels

The mechanical properties of high strength mortars produced with fine waste concrete aggregate (FWCA) and GGBFS were investigated. The natural sand was replaced by FWCA with different levels, namely 0, 25, 50, 75, and 100%. The ordinary Portland cement (OPC) was substituted by GGBFS with 0, 30, and 60% by weight. To satisfy the requirements of high strength, all the mortar mixes were made with a 0.25 w/bratio. The hardened mortars were tested for compressive strength, splitting tension, and fracture parametersat different ages.The experimental findings showed that the mixtures with FWCA showed lower strength, fracture energy and toughness compared to the corresponding reference mixes at a given age and GGBFS content. The 30% replacement of OPC by GGBFS improved the strengths of all mixes at 28 and 90 days. Moreover, the use of 30% GGBFS counterbalanced the strength decrement due to the use of the FWCA such that the mixtures with FWCA and GGBFS showed strengths comparable to or even exceeded the strengths of the mixtures made with natural sand only.

Decomposition of the metastable beta titanium alloy Ti-15-3

1983 ◽  
Vol 41 ◽  
pp. 264-265
Author(s):  
Y. L. Chen ◽  
S. Fujlshiro
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Alpha Phase ◽  
Thick Sheet ◽  
Omega Phase ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Beta Matrix ◽  
Metastable Beta ◽  
Very High

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

HREM interface studies in SiC-whisker-reinforced Al2O3 and Si3N4 ceramics

1988 ◽  
Vol 46 ◽  
pp. 734-735
Author(s):  
W. Braue ◽  
R.W. Carpenter ◽  
D.J. Smith
Keyword(s):  
Analytical Data ◽  
Base Material ◽  
High Strength ◽  
Ceramic Composites ◽  
Good Thermal Stability ◽  
All Ceramic ◽  
Sic Whiskers ◽  
Base Composite ◽  
C 30 ◽  
Si3n4 Ceramics

Whisker and fiber reinforcement has been established as an effective toughening concept for monolithic structural ceramics to overcome limited fracture toughness and brittleness. SiC whiskers in particular combine both high strength and elastic moduli with good thermal stability and are compatible with most oxide and nonoxide matrices. As the major toughening mechanisms - crack branching, deflection and bridging - in SiC whiskenreinforced Al2O3 and Si3N41 are critically dependent on interface properties, a detailed TEM investigation was conducted on whisker/matrix interfaces in these all-ceramic- composites.In this study we present HREM images obtained at 400 kV from β-SiC/α-Al2O3 and β-SiC/β-Si3N4 interfaces, as well as preliminary analytical data. The Al2O3- base composite was hotpressed at 1830 °C/60 MPa in vacuum and the Si3N4-base material at 1725 °C/30 MPa in argon atmosphere, respectively, adding a total of 6 vt.% (Y2O3 + Al2O3) to the latter to promote densification.

Precipitation in Al-Li-Zr alloys

1992 ◽  
Vol 50 (1) ◽  
pp. 186-187
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Fracture Toughness ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Transmission Electron ◽  
Water Quench ◽  
Aluminum Lithium ◽  
Aluminum Lithium Alloys ◽  
Lithium Alloys ◽  
Zr Alloys

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.

Microstructure of an extruded rapidly solidified Al-8Fe-2Mo alloy

1986 ◽  
Vol 44 ◽  
pp. 548-549
Author(s):  
W. T. Donlon ◽  
J. E. Allison ◽  
S. Shinozaki
Keyword(s):  
Electron Microscopy ◽  
Automotive Industry ◽  
Fuel Economy ◽  
High Strength ◽  
Al Alloys ◽  
Light Weight ◽  
Thin Sections ◽  
Strength And Durability ◽  
Rapidly Solidified ◽  
Whitney Aircraft

Light weight materials which possess high strength and durability are being utilized by the automotive industry to increase fuel economy. Rapidly solidified (RS) Al alloys are currently being extensively studied for this purpose. In this investigation the microstructure of an extruded Al-8Fe-2Mo alloy, produced by Pratt & Whitney Aircraft, Goverment Products Div. was examined in a JE0L 2000FX AEM. Both electropolished thin sections, and extraction replicas were examined to characterize this material. The consolidation procedure for producing this material included a 9:1 extrusion at 340°C followed by a 16:1 extrusion at 400°C, utilizing RS powders which have also been characterized utilizing electron microscopy.

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