Experimental and Theoretical Study on Mechanical Properties of Concrete under Triaxial Compression after Suffering High Temperature

2011 ◽  
Vol 243-249 ◽  
pp. 218-221
Author(s):  
Jia Wei Yao ◽  
Yu Pu Song ◽  
Ling Xia Gao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Stress Ratio ◽  
Triaxial Compression ◽  
High Temperature Mechanical Properties ◽  
Multiaxial Compression ◽  
Strength And Deformation ◽  
Stress Ratios ◽  
As Stress

Little progress has been made in experimental studying on high-temperature mechanical properties of concrete under multiaxial compression. Triaxial proportional compressive tests of ordinary concrete after suffering to high temperature (200°C ~600°C) were carried out, the designed stress ratios are 0.1:0.25:1, 0.1:0.5:1, 0.1:0.75:1 and 0.1:1:1. The failure models of concrete specimens after suffering high temperature were observed. The biaxial compressive strength and deformation characteristics of which were measured. The influences of temperature and stress ratio were analyzed. On the basis of the analysis, the relationship between compressive strength and temperature as well as stress ratio was established in octahedral stress space.

Experimental Study on the Strength and Deformation Quality of Granite with Effect of High Temperature

2012 ◽  
Vol 226-228 ◽  
pp. 1275-1278 ◽  
Author(s):  
Xiao Li Xu ◽  
Feng Gao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
High Temperature ◽  
Reference Value ◽  
Effect Of Temperature ◽  
Rock Crystal ◽  
Brittle Ductile Transition ◽  
Strength And Deformation ◽  
Temperature Strain

Experiments on granite under uniaxial compression at high temperature of 25~850°C and after high temperature of 25~1300°C were conducted to study the effect of temperature on rock strength and deformation quality. The results show that: (1) Fitting curves between temperature strain and thermal expansion coefficient with temperature are closely first order growth exponential function relation at high temperature. Temperature strain has mutagenicity after high temperature, which can not reflect rock deformation law at high temperature exactly. (2)Mechanical properties of granite weak continuously at high temperature. Compressive strength and elastic modulus show second order attenuation trend of exponential law. But mechanical properties show mutation state after high temperature, which is closely related to the alteration of rock crystal form and brittle-ductile transition. Regression curves between compressive strength and elastic modulus with temperature are closely polynomial curve. The results reflect the fundamental regulation of granite’s interior structure changing under the action of different temperature, which will provide some reference value to rock engineering involved in high temperature.

Performance of ilmenite concrete at sustained elevated temperatures

1988 ◽  
Vol 15 (5) ◽  
pp. 776-783
Author(s):  
H. S. Wilson
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Key Words ◽  
Elevated Temperatures ◽  
Cement Ratio ◽  
Nondestructive Tests ◽  
High Temperature Mechanical Properties ◽  
Curing Period

Two similar mixes were made with cement contents of about 350 kg/m3 and a water–cement ratio of 0.50. The concrete specimens, moist cured for 7 days, were cured in air for 28 and 120 days, respectively, prior to heating. The exposure temperatures were 75, 150, 300, and 450 °C. The periods of exposure at each temperature were 2, 30, and 120 days.The compressive strengths, before heating, of the specimens cured for 35 and 120 days were 41.0 and 46.2 MPa, respectively, and the flexural strengths were 4.9 and 5.8 MPa. Compared with those strengths, the strengths of the specimens heated for 30 days or more increased at 75 °C but decreased at higher temperatures. The losses increased with increase in temperature, reaching about 30% at 450 °C.The flexural strength of the concrete cured in air for 28 days was more adversely affected than was the compressive strength. The flexural and compressive strengths of the concrete cured in air for 120 days were affected to about the same degree. The longer curing period had little effect on the relative losses in compressive strength, but the longer curing period reduced the loss in flexural strength. In most applications, the loss in strength could be compensated by proportioning the mix to overdesign for strength. Key words: high-density concrete, ilmenite, aggregates, high temperature, mechanical properties, nondestructive tests.

Experimental Study on Mechanical Properties of Concrete under Triaxial Compression

2011 ◽  
Vol 261-263 ◽  
pp. 256-259
Author(s):  
Jia Wei Yao ◽  
Yu Pu Song ◽  
Li Kun Qin ◽  
Ling Xia Gao
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Construction Material ◽  
Triaxial Compression ◽  
Uniaxial Stress ◽  
State Construction ◽  
Deformation Behaviors ◽  
Strength And Deformation ◽  
Stress Ratios ◽  
Compressive Tests

Traxial compressive tests on concrete samples subjected to such stress ratios as 0.1:0.25:1, 0.1:0.5:1, 0.1:0.75:1and 0.1:1:1, were performed. Based on mechanical properties measured from the tests, strength and deformation behaviors of concrete under triaxial compression were explored, and then the failure criterion was proposed. The result indicated that the bearing capacity of concrete under triaxial compression is greater than that under uniaxial stress state. Construction material can be greatly reduced considering this factor in design.

Influence of Freeze-Thaw Cycles on Multiaxial Strength of Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2715-2718
Author(s):  
Li Kun Qin ◽  
Ling Xia Gao ◽  
Hong Wei Song
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Stress Ratio ◽  
Theoretical Foundation ◽  
Cold Environment ◽  
Freeze Thaw ◽  
Ordinary Concrete ◽  
Multiaxial Compression ◽  
Compressive Strength Of Concrete

Mechanical properties experiments of concrete after 0, 25, 50 and 75 freeze-thaw cycles under uniaxial and multiaixial compression were carried out. The uniaxial and multiaxial compressive strengths of ordinary concrete after freeze-thaw cycles were measured. According to the experiment results, the influence of freeze-thaw cycles on the ultimate compressive and tensile strength was analyzed systematically. The influence law of freeze-thaw cycles on compressive strength of concrete under multiaxial compression was obtained. The results indicate that the compressive strength of ordinary concrete after freeze-thaw cycles under multiaxial compression is higher than that under uniaxial compression, and the degree of improvement is depended on its stress ratio. This conclusion can propose theoretical foundation for design of concrete structures in cold environment

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

BERYLCO NICKEL ALLOY 440

Alloy Digest ◽  
1975 ◽  
Vol 24 (9) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Nickel Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Electronic Components ◽  
High Temperature Mechanical Properties ◽  
Temperature Performance ◽  
Solution Treated ◽  
Complex Shapes

Abstract BERYLCO NICKEL ALLOY 440 is an age-hardenable nickel-beryllium-titanium alloy that offers high strength, excellent spring properties outstanding formability, good high-temperature mechanical properties, and resistance to corrosion and fatigue. Complex shapes can be produced in the solution-treated (soft) condition and then aged to a minimum tensile strength of 215,500 psi. It is used for mechanical and electrical/electronic components in the temperature range -320 to 800 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-94. Producer or source: Kawecki Berylco Industries Inc.. Originally published September 1964, revised September 1975.

HASTELLOY ALLOY S

Alloy Digest ◽  
1973 ◽  
Vol 22 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Heat Treating ◽  
High Temperature Alloy ◽  
Excellent Thermal Stability ◽  
Cabot Corporation ◽  
High Temperature Mechanical Properties ◽  
Temperature Performance ◽  
Resistance To Oxidation ◽  
Nickel Base

Abstract HASTELLOY alloy S is a nickel-base high-temperature alloy having excellent thermal stability, good high-temperature mechanical properties and excellent resistance to oxidation up to 2000 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-184. Producer or source: Stellite Division, Cabot Corporation.

High temperature mechanical properties of Inconel 718 pulsed Nd–YAG laser welds

2006 ◽  
Vol 23 (1) ◽  
pp. 29-37 ◽  
Author(s):  
G.D. Janaki Ram ◽  
A. Venugopal Reddy ◽  
K. Prasad Rao ◽  
G. Madhusudhan Reddy
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Inconel 718 ◽  
Yag Laser ◽  
High Temperature Mechanical Properties ◽  
Laser Welds
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