Very High Strength Cfment-Based Materials – a Prospective

1984 ◽  
Vol 42 ◽  
Author(s):  
Sidney Diamond
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
High Technology ◽  
Critical Crack ◽  
Shrinkage Cracking ◽  
Cement Pastes ◽  
Air Voids ◽  
Shrinkage Cracks ◽  
Cement Based Materials ◽  
Very High

AbstractAn attempt is made to provide a prospective on new very high strength cement based materials. The mechanical properties of concrete and of conventional cement pastes are considered, and limitations on the behavior of paste set by the Griffith concept of a critical crack explored. Evidence is cited confirming that spherical air voids do indeed act as critical Griffith flaws in undried pastes; however it is suggested that shrinkage cracks dominate the behavior of cement paste exposed to drying. Very high strength systems.must avoid both large air voids and other pores and also be resistant to shrinkage cracking. Streams of development leading to “DSP” (Aalborg) and “MDF” (ICI) systems are described, and details of the functioning of the two classes of product are described. Current and potential commercial developments are briefly noted, and possible interrelations with the emerging areas of “high technology ceramics” mentioned. Finally, a brief summary of relevant mechanical properties is provided.

Relationships between Strength and Microstructure for Cement-Based Materials: an Overview

1984 ◽  
Vol 42 ◽  
Author(s):  
Sidney Mindess
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
High Strength ◽  
Pore Geometry ◽  
Precise Form ◽  
Cement Based Materials ◽  
Very High

AbstractThe mechanical properties of cement-based materials must be controlled by the microstructure, pore geometry and chemical composition of the cement, by the properties of the aggregate, and by the nature of the cement-aggregate bond. While the precise form of the strength vs. microstructure relationship is as yet only imperfectly understood, enough is known to permit us to predict what alterations in the microstructure are required for the production of materials with very high strengths. There are also techniques available for reducing the brittleness that is often a characteristic of high-strength materials. The present paper presents an overview of the strength vs. microstructure relationships that can be used to predict the properties of high strength cement-based materials, and a brief review of some of the methods for achieving high strengths.

UNS A97075

Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Applications ◽  
Structural Parts ◽  
Very High

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.

Cement in the context of new materials for an energy-expensive future

1983 ◽  
Vol 310 (1511) ◽  
pp. 31-42 ◽  
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
High Strength ◽  
Hardened Cement ◽  
New Materials ◽  
Biological Origin ◽  
Cement Pastes ◽  
Inorganic Solids ◽  
Mild Conditions ◽  
Hardened Cement Pastes

Hydraulic cements are energy-cheap relative to other common materials, are manufactured on a large scale and, when mixed with water, form readily mouldable pastes that harden at low temperature. In a technological sense, such pastes can be regarded as inorganic ‘plastics’, but the types of article that can usually be fabricated from the cements has been restricted by the low tensile strength and fracture toughness of hardened cement pastes. Poor mechanical properties are not inherent in inorganic solids formed under mild conditions; mineral structures of biological origin can display relatively high strength and useful toughness as a result of microstructural features determined by biopolymers. Recent studies have shown that the low tensile properties of cement paste result from the presence of macroscopic pores. The elimination of such defects by the use of polymeric rheology modifiers gives unreinforced cement pastes a flexural strength of 150 MPa or more. Such novel materials should considerably extend the range of uses for hydraulic cements.

Effect of Different Heat Treatments on Microstructure and Mechanical Properties of the Martensitic Gx12CrMoVNbN9-1 Cast Steel / Wpływ Parametrów Obróbki Cieplnej Na Mikrostrukture I Własciwosci Mechaniczne Martenzytycznego Staliwa Gx12CrMoVNbn9-1

2013 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
G. Golanski ◽  
J. Słania
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Lath Martensite ◽  
High Strength ◽  
Strength Properties ◽  
Microstructure And Mechanical Properties ◽  
Quenching And Tempering ◽  
Very High

The paper presents a research on the influence of multistage heat treatment with the assumed parameters of temperature and time on the microstructure and mechanical properties of high-chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. In the as-cast state GP91 cast steel was characterized by a microstructure of lath martensite with numerous precipitations of carbides of the M23C6, M3C and NbC type, with its properties higher than the required minimum. Hardening of the examined cast steel contributes to obtaining a microstructure of partly auto-tempered martensite of very high strength properties and impact strength KV on the level of 9-15 J. Quenching and tempering with subsequent stress relief annealing of GP91 cast steel contributed to obtaining the microstructure of high-tempered lath martensite with numerous precipitations of the M23C6 and MX type of diverse size. The microstructure of GP91 cast steel received after heat treatment was characterized by strength properties (yield strength, tensile strength) higher than the required minimum and a very high impact energy KV. It has been proved that GP91 cast steel subject to heat treatment No. 2 as a result of two-time heating above the Ac3 temperature is characterized by the highest impact energy.

scholarly journals State of the Art: Mechanical Properties of Ultra-High Performance Concrete

2017 ◽  
Vol 3 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Mohamadtaqi Baqersad ◽  
Ehsan Amir Sayyafi ◽  
Hamid Mortazavi Bak
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
State Of The Art ◽  
High Strength ◽  
Structural Members ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
The Past ◽  
Very High

During the past decades, there has been an extensive attention in using Ultra-High Performance Concrete (UHPC) in the buildings and infrastructures construction. Due to that, defining comprehensive mechanical properties of UHPC required to design structural members is worthwhile. The main difference of UHPC with the conventional concrete is the very high strength of UHPC, resulting designing elements with less weight and smaller sizes.  However, there have been no globally accepted UHPC properties to be implemented in the designing process. Therefore, in the current study, the UHPC mechanical properties such as compressive and tensile strength, modulus of elasticity and development length for designing purposes are provided based on the reviewed literature. According to that, the best-recommended properties of UHPC that can be used in designing of UHPC members are summarized. Finally, different topics for future works and researches on UHPC’s mechanical properties are suggested.

scholarly journals Mechanical Properties of 2Y-TZP Fabricated from Detonation Synthesized Powder

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 440-452
Author(s):  
Frank Kern ◽  
Andrea Gommeringer
Keyword(s):  
Mechanical Properties ◽  
Shear Bands ◽  
High Strength ◽  
Yttria Stabilized Zirconia ◽  
Detonation Synthesis ◽  
Stabilized Zirconia ◽  
Weak Correlation ◽  
High Toughness ◽  
Secondary Cracks ◽  
Very High

Yttria stabilized zirconia (Y-TZP) is frequently used in dental and engineering applications due to its high strength and fracture resistance. In this study, 2Y-TZP samples were manufactured from commercially available powder produced by detonation synthesis. Tests of the mechanical properties exhibited an unusual combination of both very high strength and toughness. The materials show a very weak correlation between toughness and grain size. The transformability, measurable by XRD, cannot explain the high toughness. Fractographic analysis revealed a broad transformation affected zone with secondary cracks and shear bands on the tensile side of bending bars which can be made responsible for the high toughness and non-linear stress–strain curves.

Compressive and Shearing Mechanical Anisotropy of Aluminum after ECAP

2014 ◽  
Vol 1016 ◽  
pp. 100-104
Author(s):  
Cleber Granato de Faria ◽  
Tércio Assunção Pedrosa ◽  
Roberto Braga Figueiredo ◽  
Maria Teresa Paulino Aguilar ◽  
Paulo Roberto Cetlin
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Cross Section ◽  
High Strain ◽  
High Strength ◽  
The Other ◽  
Mechanical Anisotropy ◽  
Single Plane ◽  
Angular Pressing ◽  
Very High

Severe plastic deformation (SPD), where metals are deformed up to very high strain values, leads to a very small grain size and a high strength of the material. ECAP (Equal Channel Angular Pressing) is one of the SPD methods, and involves the extrusion of a metal billet through two intersecting channels with identical cross-section and forming an angle between them. The material undergoes shearing as it crosses from one channel to the other, but its external dimensions are not altered. Shearing occurs along a single plane, which may lead to anisotropy in the mechanical properties of the material after ECAP. Compression, tension and shearing tests along various directions in the as-processed specimens indicated the presence of mechanical anisotropy in ECAP processed aluminum.

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