scholarly journals Discussion: A study of the relationship between time, strength, deformation and fracture of plain concrete

1973 ◽  
Vol 25 (85) ◽  
pp. 222-223
Author(s):  
R. K. Dhir ◽  
C. M. Sangha ◽  
C. T. Tam
Keyword(s):  
Plain Concrete ◽  
Deformation And Fracture ◽  
Time Strength ◽  
The Relationship

Rockburst Prediction Based on Electromagnetic Radiation Technology and its Application

2014 ◽  
Vol 1010-1012 ◽  
pp. 1564-1567 ◽  
Author(s):  
Chao Wang ◽  
Wei Peng
Keyword(s):  
Electromagnetic Radiation ◽  
Rock Burst ◽  
Monitoring Method ◽  
Radiation Technology ◽  
Working Face ◽  
Deformation And Fracture ◽  
Short Period ◽  
Coal Rock ◽  
Relationship Of ◽  
The Relationship

Rock bursts are serious threats to safety and production in coalmines, which are becoming more serious with the increase in mining intensity and depth. Electromagnetic radiation (EMR) always occurs along with coal rock deformation and fracture. EMR monitoring technique, the method using the short period changes of EMR signals before rock burst, has been widely applied to monitor and predict rock burst. This paper mainly studied the relationship of EMR generated by coal rock mass to applied loads and monitored the working face and roadways of coalmine by monitoring instrument, the results show that the EMR monitoring method has excellent performance in predicting rock burst.

The Effect of Silica Nanoparticles and Cellulosic Fibers on the Compressive, Tensile and Flexural Properties of Ordinary Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 515-519
Author(s):  
Mohammad Foroughi ◽  
Marzieh Kadivar ◽  
Mohammad Mehdi Nabavi ◽  
Mohammad Reza Kadivar
Keyword(s):  
Tensile Strength ◽  
Silica Nanoparticles ◽  
Plain Concrete ◽  
Cellulose Fibers ◽  
Nano Materials ◽  
Ordinary Concrete ◽  
Cellulosic Fibers ◽  
Long Period ◽  
Short Period ◽  
The Relationship

The present paper is a laboratory study on the effect of using silica nanoparticles with cellulose fibers in increasing compressive, flexural and tensile strength of concrete and the results has been compared with ordinary concrete made of cement alone. Evaluation is conducted based on a 28-day long period, and a 7-day short period; the results showed that the concrete containing a small percentage of nanoparticles, with a determined ratio of water and cement, in comparison with ordinary concrete with the same water and cement ratio, has improved considerably. For comparison, compressive, flexural and tensile strength of plain concrete and the concrete containing cellulose fibers is also measured. The results show that by each of these three criteria, strength of concrete containing nano-materials and the cellulosic fibers has been increased considerably. Finally, the relationship between compressive, flexural and tensile strength of concrete shows that the tensile and flexural strength of the concrete containing nanoparticles increases by increasing compressive strength.

scholarly journals Study on Strength and Ultrasonic Velocity of Air-Entrained Concrete and Plain Concrete in Cold Environment

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huai-shuai Shang ◽  
Ting-hua Yi ◽  
Xing-xing Guo
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Ultrasonic Velocity ◽  
Concrete Structure ◽  
Plain Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Testing Technology ◽  
The Relationship ◽  
Air Entrained Concrete

Nondestructive testing technology is essential in the quality inspection of repair, alteration, and renovation of the existing engineering, especially for concrete structure in severe environment. The objective of this work is to deal with the behavior of ultrasonic velocity and mechanical properties of plain concrete and air-entrained concrete subjected to freeze-thaw cycles (F-T-C). The ultrasonic velocity and mechanical properties (tensile strength, compressive strength, cubic compressive strength, and splitting strength) of C30 air-entrained concrete and plain concrete with different water-cement ratio (water-cement ratio was 0.55, 0.45, and 0.50, resp.) after F-T cycles were measured. The influences of F-T cycles on ultrasonic velocity and mechanical properties of C30 air-entrained concrete and plain concrete were analyzed. And the relationship between mechanical properties and ultrasonic velocity was established. The experimental results can be useful for the design of new concrete structure, maintenance and life prediction of existing concrete structure such as offshore platform and concrete dock wall.

Discussion: Deformation and fracture of plain concrete

1979 ◽  
Vol 31 (109) ◽  
pp. 243-245
Author(s):  
P. G. Lowe ◽  
E. J. Hearn ◽  
Michael D. Kotsovos ◽  
John B. Newman
Keyword(s):  
Plain Concrete ◽  
Deformation And Fracture

Study on Influence of Freeze-Thaw for Chlorion Penetration

2014 ◽  
Vol 578-579 ◽  
pp. 1295-1298
Author(s):  
Zhen Qiang Wang ◽  
Ya Na Zhang ◽  
Yan Liu
Keyword(s):  
Concrete Strength ◽  
Chloride Ion ◽  
Plain Concrete ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Chloride Diffusivity ◽  
Chloride Ion Penetration ◽  
Freezing And Thawing Cycles ◽  
Relationship Of ◽  
The Relationship

Freeze-thaw cycles can affect the chloride diffusivity of concrete to a certain extend. The experimental study of plain concrete specimens with different strength grade were carried out, suffering 0, 50, 100 and 150 cycles of freeze-thaw. Chloride ion penetration under different strength, different cycle-index and the concrete mass-loss caused by freeze-thaw cycles are analyzed. Using this method the relationship of chlorion permeability with concrete strength is established when the concrete specimens reach to a particular value of freezing and thawing cycles.

Characteristics Analysis of Acoustic Emission Signals from Titanium under Tensile Fracture

2011 ◽  
Vol 335-336 ◽  
pp. 1459-1464
Author(s):  
Jian Shi ◽  
Peng Wang
Keyword(s):  
Acoustic Emission ◽  
Fracture Process ◽  
Crack Opening ◽  
Tensile Fracture ◽  
Opening Displacement ◽  
Emission Signal ◽  
Deformation And Fracture ◽  
Characteristics Analysis ◽  
The Relationship ◽  
Tension Fracture

The parameters of acoustic emission signals were analyzed which titanium plate specimens with crack under tension fracture process used acoustic emission technique. Based on the results of stress-strain curves, crack opening displacement-time curves and CCD images, the relationship between parameters of acoustic emission signal and mechanical behavior of the titanium was investigated. The results show acoustic emission signals increased significantly during yield, crack propagation and fracture with different load speeds, the energy amplitude range of acoustic emission signals was mainly from 50dB to 65dB. The characteristic parameters including AE energy, hit and amplitude can be used to represent the mechanical and inner deformation form of titanium during plastic deformation and fracture process.

Study on Joint Deflection of Existing Joint Plain Concrete Pavement upon Adoption of Hot Mixture Asphalt Overlay

2011 ◽  
Vol 462-463 ◽  
pp. 253-258
Author(s):  
Jing Song Shan ◽  
Zhong Yin Guo
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Plain Concrete ◽  
Element Model ◽  
Basic Mechanism ◽  
Concrete Pavement ◽  
Reflection Cracking ◽  
Asphalt Overlay ◽  
The Relationship ◽  
The Finite Element Model

When HMA (hot mixture asphalt) is used to remedy functional or structural deficiencies of existing JPCP (joint plain concrete pavement), reflection cracking is a major distress mode in HMA overlay. The basic mechanism of reflection cracking is the propagation of cracks through the overlay due to deflection difference in the joints vicinity of the existing pavements. In this paper the model of JPCP is created by three finite element method and the relationship between joint deflection difference and effects such as base modulus, elastic coefficient of spring elements is discussed. Based on the model of JPCP, the finite element model of asphalt overlay is created then and shear stress concentration phenomenon is found at the bottom of HMA where is just above the joint of JPCP. So, the rule of the shear stress at the bottom of HMA with deflection difference at the joint of JPCP is studied.

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