Bond behavior between cement-based grouting material and steel bar under repetitive loading after being exposed to high temperature at early age

2020 ◽  
Vol 262 ◽  
pp. 120023
Author(s):  
Guanglin Yuan ◽  
Zhiyuan Zhao ◽  
Qingtao Li
Keyword(s):  
High Temperature ◽  
Early Age ◽  
Bond Behavior ◽  
Grouting Material ◽  
Steel Bar ◽  
Repetitive Loading

Experimental Study on Horizontal Shear Crack Control of Prestressed Corrugated Composite Beams

2015 ◽  
Vol 784 ◽  
pp. 391-396
Author(s):  
Seung Un Chae ◽  
Bum Yean Cho ◽  
Oh Sang Kweon ◽  
Heung Youl Kim
Keyword(s):  
High Temperature ◽  
Brittle Failure ◽  
Composite Beam ◽  
Shear Crack ◽  
Reverse Direction ◽  
Horizontal Shear ◽  
Lateral Shear ◽  
Crack Control ◽  
Fire Resistance Test ◽  
Steel Bar

In case the structure is exposed to the high temperature, the lateral shear crack is the major cause exposing the steel bar to the high temperature and also the major cause of the collapse of buildings. In the study, in order to control the lateral shear crack, the presterssing using strands in a reverse direction of the lateral shear crack has applied and the fire resistance test of the PS corrugated web composite beam has been carried out, produced in a corrugated type of the steel to increase the efficiency of the prestressing. As a result of the test, the lateral shear crack introducing the PS has been reduced but it has been concluded that in case the strands are failed, the brittle failure can be taking place.

Effects of heat stress on growth, some blood variables and lipid oxidation in broilers exposed to high temperature at an early age

2000 ◽  
Vol 41 (4) ◽  
pp. 489-493 ◽  
Author(s):  
O. Altan ◽  
A. Altan ◽  
I. Oguz ◽  
A. Pabuçcuoglu ◽  
S. Konyalioglu
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Lipid Oxidation ◽  
Early Age ◽  
Blood Variables

Bond Behavior of Reinforcing Steel Bar and Geopolymer Concrete

2020 ◽  
Vol 32 (7) ◽  
pp. 04020167
Author(s):  
Rakesh Paswan ◽  
Md. Reyazur Rahman ◽  
S. K. Singh ◽  
B. Singh
Keyword(s):  
Geopolymer Concrete ◽  
Reinforcing Steel ◽  
Bond Behavior ◽  
Steel Bar

scholarly journals Effects of the corrosion of main bar and stirrups on the bond behavior of reinforcing steel bar

2019 ◽  
Vol 225 ◽  
pp. 13-28 ◽  
Author(s):  
Hongwei Lin ◽  
Yuxi Zhao ◽  
Jia-Qi Yang ◽  
Peng Feng ◽  
Josko Ozbolt ◽  
...  
Keyword(s):  
Reinforcing Steel ◽  
Bond Behavior ◽  
Steel Bar

scholarly journals Mechanical Characteristics of Cement-Based Grouting Material in High-Geothermal Tunnel

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1572 ◽  
Author(s):  
Mingnian Wang ◽  
Yunpeng Hu ◽  
Cheng Jiang ◽  
Yicheng Wang ◽  
Dagang Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Mechanical Characteristics ◽  
Coupling Effect ◽  
Peak Stress ◽  
Curing Temperature ◽  
Peak Strain ◽  
Humidity Effect ◽  
Grouting Material ◽  
Study Results

The cement-based grouting materials used for practical purposes in high-geothermal tunnels are inevitably affected by humidity and high temperature, leading to the deterioration of mechanical properties. Based on the characteristics of changing high temperatures and two typical conditions of hot-humid and hot-dry environments in high-geothermal tunnels, many mechanical strength tests were carried out on the grouting material cured under different environmental conditions. The study results indicated that high temperature and low relative humidity were unfavorable to the development of mechanical characteristics of grouting material, but the coupling effect of two factors could improve the strength at early ages and reduce the degradation of long-term strength. As the curing temperature exceeded 56.3 °C, the humidity effect on strength played a more important role in recovering the strength of grouting material damaged by high temperature. Temperature had more significant impact on the relative peak stress while the relative humidity had greater influence on the relative peak strain. A calculation compressive constitutive model was prospered, which considering both temperature and relative humidity. The study results may provide much valuable experimental data and theoretical supporting for the design of compression constitutive of cement-based grouting material in high-geothermal tunnel.

scholarly journals Effects of Shrinkage Reducing Agent and Expansive Additive on Plastic Shrinkage of Mortar at Different Temperatures

2018 ◽  
Vol 206 ◽  
pp. 02002
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee ◽  
Shigeyuki Date
Keyword(s):  
High Temperature ◽  
Setting Time ◽  
Reducing Agent ◽  
Early Age ◽  
Initial Setting Time ◽  
Plastic Shrinkage ◽  
Different Temperatures ◽  
Expansive Additive ◽  
Hot Weather ◽  
Shrinkage Reducing Agent

In the construction, it is inevitable to perform plaster work in hot weather which causes the dehydration and rapid shrinkage on the paste during the early age. This research shows the studies of reducing the plastic shrinkage of mortar during the early age with such additives as the Shrinkage Reducing Agent (SRA), the Expansive Additive (EX), and the Fly Ash (FA) in controlled temperatures at 30°C and 40°C, with relative humidity between 60% and 70% according to the ASTM C1579-06 standard, with the strain gauge installed at 0.5 cm.from the surface. The shrinkage rate was measured starting from the Initial Setting Time and every 10 minutes afterwards for 24 hours. The results show that high temperature effects the cracking and how to use different formulas of additive under different circumstances is considerably important. To use only one additive is not sufficient in high temperature. To use the SRA in addition to the EX enhances better expansion than to use only the EX. Moreover, it is recommended to pay close attention in adding large amount of the FA into mortar with the EX and SRA added which extremely enhances the expansion and potential cracking.

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