Mechanical and Rheological Properties of Aluminous Cement under High Temperatures

2014 ◽  
Vol 982 ◽  
pp. 141-144 ◽  
Author(s):  
Ondřej Holčapek ◽  
Pavel Reiterman ◽  
Petr Konvalinka
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Rheological Properties ◽  
Cement Paste ◽  
Rheological Behavior ◽  
Experimental Program ◽  
Before And After ◽  
Aluminous Cement ◽  
Strength In Bending

The following article deals with the relations between rheological behavior and strength characteristics of high aluminous cement paste. There were investigated the values of flow of fresh mixture (tested with Högermann ́s table), tensile strength in bending and compressive strength at the age of 28 days on specimens 40 x 40 x 160 mm. The influence of high temperature was examined by exposure to 600 °C and 1000 °C. The results of provided experimental program confirm the fact that with increasing water-cement ration decreases compressive and tensile strength before and after temperature loading. Also was shown the effect of high temperature on refractory aluminous cement paste properites.

Influence of Ceramic Fibers on Mechanical Characteristics of Refractory Composites

2014 ◽  
Vol 1054 ◽  
pp. 22-26
Author(s):  
Ondřej Holčapek ◽  
Pavel Reiterman ◽  
Petr Konvalinka
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Cement Composite ◽  
Ceramic Fibers ◽  
Explosive Spalling ◽  
Industrial Sectors ◽  
Temperature Load ◽  
Before And After ◽  
Strength In Bending

New and unexpected way of using cement composite in industrial sectors represents a current challenge for many research teams all over the world. Following contribution deals with the study of fiber-cement composite ́s mechanical properties after exposure to high temperature. This composite could be used for industry applications or for fire-resistance cladding production. Tensile strength in bending, compressive strength, bulk density and dynamic modulus of elasticity were examined on samples 40 x 40 x 160 mm. All parameters were measured before and after exposure to high temperature in electric furnace. One group contained three specimens was reference, without temperature load, the second group was exposure to 600 °C and the last one to 1000 °C. High aluminous cement Secar®71 works as refractory binder and nature crushed basalt aggregates two fractions works as filler. The composite ́s matrix was supplemented by various amounts of ceramic fibers. Especially the influence of amount of fibers on final properties was the main goal of this research. Measured mechanical parameters provide deep knowledge of their behavior after temperature on 1000 °C level. The compressive strength and tensile strength in bending achieved values 1.5 MPa. Behavior of the composite during and after temperature load was without any negative phenomena such as explosive spalling, cracks in aggregates or cement paste and macro disintegration of the composite ́s structure.

Changes of the Properties of Cement Paste with Fly Ash Exposed to the High Temperature

2016 ◽  
Vol 677 ◽  
pp. 138-143
Author(s):  
Romana Lovichová ◽  
Pavel Padevět ◽  
Jindřich Fornůsek
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
Cement Paste ◽  
Material Properties ◽  
Bound Water ◽  
Material Structure ◽  
Cement Pastes ◽  
Strength In Bending

This paper describes influence of exposure to high temperatures on material properties of cement paste with addition of fly ash. The properties of cement pastes are significant to the assumption behaviour of concrete and concrete structures. In the cement paste containing fly ash, the effect of high temperature up to 600 ° C causes the changes of content in physically bound water and the change in the material structure. The results of research indicate changes that are reflected in the material properties of the cement paste as compressive strength, tensile strength in bending.

Experimental Analysis of Hydrothermal Curing Influence on Properties of Fiber-Cement Composite

2015 ◽  
Vol 732 ◽  
pp. 55-58 ◽  
Author(s):  
Ondřej Holčapek ◽  
Pavel Reiterman ◽  
Petr Konvalinka
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Cement Composite ◽  
Cement Composites ◽  
Research Activity ◽  
Temperature Resistance ◽  
Hydrothermal Curing ◽  
Aluminous Cement ◽  
Curing Condition ◽  
Strength In Bending

Special industrial application of fiber-cement composites is currently one important issue of concrete industry and research activity. The field of refractory and high-temperature resistance materials is very large and contains the cement composites too. Hydrothermal curing together with using aluminous cement with refractory basalt aggregates and fibers shows high potential for its applications in high temperature. These composite is characterized by compressive strength over 140 MPa and tensile strength in bending 12 MPa (investigated on specimens 40 x 40 x 160 mm). After exposure to temperature 1000 °C these parameters are 60 MPa in compression respective 6 MPa in bending. Achieved values are significantly higher than in the case of laboratory curing condition and there are suitable especially for prefabricated fire resistance cladding or other special application in the industry.

scholarly journals Investigation on Mechanical and Durability Properties of Rapid Strength Gaining Concrete

2018 ◽  
Vol 7 (2.12) ◽  
pp. 406
Author(s):  
L Krishnaraj ◽  
P T. Ravichandran ◽  
Shaik AarifIlahi ◽  
V Ramanathan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Cement Paste ◽  
Mechanical Tests ◽  
High Rate ◽  
Concrete Technology ◽  
Strength Concrete ◽  
Durability Properties ◽  
Content Ratio ◽  
Strength Tests

The strength of cement paste and aggregate components helps to decide the strength of the concrete, their properties of deformation, and the binding properties among the aggregate surface and cement paste. It is conceivable with many of the aggregates to form high strength concrete by increasing the cement paste strength, which can be controlled by choosing of water-content ratio and type of admixture dosage. The current scenario in the concrete technology and the accessibility of many kind of mineral and chemical admixtures, and special super plasticizer to gain the targeted compressive strength of a concrete. In this study MYK Remicrete PC30 and BASF Master Glennium ACE 30 were utilized as the admixtures as Add 1 and Add 2 which acts as high rate water reducing agents. These developments have led to increase uses of Rapid strength concrete. To compare the mechanical and durability properties of concrete using Fly ash and Admixtures the following tests were conducted on concrete tests specimens. Mechanical tests are to be conducted such as compressive strength tests, and tensile strength tests, durability tests like water absorption test, acid test by HCL, H2SO4 and HNO3. The result indicates that rate of development of compressive strength and tensile strength are higher for the concrete design mix which has HRWR admixture of 1% and FA of 20%.  

Study on Crystallization and Rheological Behavior of PEN/PET Blends

2013 ◽  
Vol 830 ◽  
pp. 72-75 ◽  
Author(s):  
Cheng Zhi Chuai ◽  
Kai Li
Keyword(s):  
Tensile Strength ◽  
Rheological Property ◽  
Rheological Properties ◽  
Rheological Behavior ◽  
Impact Resistance ◽  
Crystallization Rate ◽  
Nucleating Agent

The crystallization and rheological properties of PET were studied by using capillary remoter and plate remoter in the paper. The results showed that the addition of PEN could improve the rheological property of PEN/PET blends and the addition of PC could improve the toughness of PEN/PET blends. Besides, Nucleating agent could accelerate the crystallization rate and form crystal particles with small dense in order to improve the properties of impact resistance, tensile strength and transparency of products.

Behavior of Cement Composites Loaded by High Temperature

2015 ◽  
Vol 824 ◽  
pp. 121-125
Author(s):  
Veronika Špedlová ◽  
Dana Koňáková
Keyword(s):  
High Temperature ◽  
Portland Cement ◽  
High Temperatures ◽  
Experimental Program ◽  
Mechanical And Thermal Properties ◽  
Cement Composites ◽  
Basalt Fibers ◽  
Coefficient Of Thermal Conductivity ◽  
Aluminous Cement ◽  
Better Than

In this paper, there are summarized the results of an experimental program focused on basic, mechanical and thermal properties of cement composites according to the high – temperature loading. Four different materials were studied, which differed in used kind of cement and amount of fibers. As a matrix for studied composites the aluminous cement was chosen because of its resistance in high temperature. For a comparison the Portland cement was also tested. The second main ingredient used to provide better resistance in high temperatures - the basalt aggregate, was mixed in every specimen. The basalt fibers were chosen for two of the measured samples, remaining two ones were tested without fibers. The obtained data in this presented analyses show that the application of the aluminous cement leads to increase (depending on temperature) of porosity, which is the cause of decreasing of the coefficient of thermal conductivity. It can seems, that these cement composites will have low mechanical strength in high temperatures, but because of better sintering, the aluminous cement keeps its strength in high temperatures better than Portland cement.

NICKEL COPPER CAST ALLOY 410

Alloy Digest ◽  
1963 ◽  
Vol 12 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Cast Alloy ◽  
Heat Treating ◽  
High Alloy ◽  
Temperature Performance ◽  
Nickel Copper

Abstract Nickel Copper Cast Alloy 410 is one of the most useful cast materials to withstand corrosives encountered in industry. It has tensile strength comparable to cast carbon steel and gives good performance under conditions of abrasion and erosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Ni-85. Producer or source: High alloy foundries.

Advanced concretes for high temperature applications

2019 ◽  
Author(s):  
Alok A. Deshpande ◽  
Dhanendra Kumar ◽  
Ravi Ranade ◽  
Andrew S. Whittaker
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Strain Hardening ◽  
Modulus Of Rupture ◽  
Direct Tension ◽  
Conventional Concrete ◽  
Normal Strength ◽  
Temperature Applications

<p>The mechanical properties of concrete deteriorate at high temperatures. Strain-hardening cementitious composites (SHCC) are a special class of fiber-reinforced concretes that exhibit strain-hardening behavior in direct tension. The mechanical behavior of a SHCC made using polyvinyl alcohol (PVA) fibers is characterized after exposure to temperatures up to 800°C. The effects of temperature on compressive strength, splitting tensile strength and modulus of rupture are reported. For comparison, a normal strength conventional concrete of similar compressive strength to the SHCC was heated and tested in the same conditions as the SHCC. The normalized tensile strength of SHCC at room temperature, and after exposure to high temperature, is significantly greater than the value for conventional concrete. The PVA fibers provide crack-bridging capacity up to about 200°C (melting point of PVA fibers is 230°C), leading to improved tensile behavior. At greater temperatures, the fibers melt, creating pathways for steam to escape, reducing micro-cracking and significantly improving mechanical behavior with respect to conventional concrete. SHCC is a robust alternative to conventional concrete for high temperature applications.</p>

High-Temperature Compression Testing of Graphite

1953 ◽  
Vol 20 (2) ◽  
pp. 289-294
Author(s):  
Leon Green
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Stress Relaxation ◽  
Temperature Control ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Limited Degree ◽  
Relaxation Curves ◽  
Short Time

Abstract Experiments on the compression of graphite cylinders at elevated temperatures are described. It is found that the short-time compressive strength increases with temperature in the range from room temperature to 2000 C, a variation which is consistent with the previously reported behavior of the tensile strength. Photographs of typical modes of deformation and their corresponding stress-strain curves are presented, but a limited degree of temperature control renders the curves semiquantitative in nature. The large, mutually opposing influences of temperature and strain rate are illustrated by photographs of typical failures, and stress-relaxation curves manifest the plasticity of graphite at high temperatures.

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