Influence of reactivity and dosage of MgO expansive agent on shrinkage and crack resistance of face slab concrete

2021 ◽  
pp. 104333
Author(s):  
Lei Wang ◽  
Xiao Lu ◽  
Xiang Li ◽  
Fanxing Guo
Keyword(s):  
Crack Resistance ◽  
Expansive Agent

scholarly journals Effect of expansive agent and internal curing agent on crack resistance of C50 silica fume wet-mix shotcrete

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881916 ◽  
Author(s):  
Feng Wei Ning ◽  
Yue Bo Cai ◽  
Yin Bai ◽  
Bo Chen ◽  
Feng Zhang
Keyword(s):  
Relative Humidity ◽  
Crack Resistance ◽  
Silica Fume ◽  
Stress Test ◽  
High Strength ◽  
Internal Curing ◽  
Ring Test ◽  
Curing Agent ◽  
Volume Deformation ◽  
Expansive Agent

High-strength shotcrete is always needed to strengthen rock support. However, it will reversely increase the crack risk. Crack normally goes against the durability and shortens the service life of shotcrete. The objective of this article was to improve the crack resistance of shotcrete with expansive agent and internal curing agent. C50 shotcrete with 10% of silica fume was taken as reference mix composition. Ring test and thermal stress test simulating actual temperature, relative humidity, and constraint were carried out to directly assess crack resistance. Restrained deformation, autogenous volume deformation, and pore structure were measured to study how expansive agent and internal curing agent resisted crack. The results indicated that 4% of expansive agent was enough to improve crack resistance of C50 shotcrete. It could fill internal pores and produce compressive pre-stress at earlier age which could be used to compensate shrinkage at later age. Furthermore, the crack resistance of C50 shotcrete could be further promoted when internal curing agent was employed together with expansive agent. The internal curing agent was able to reduce auto-shrinkage by decreasing the loss of internal relative humidity. In addition, it could also enhance the hydration degree of expansive agent, which would strengthen the role of expansive agent on resisting crack.

Adding an expansive agent to increase the toughness of steel fibre reinforced concrete

2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan
Keyword(s):  
Reinforced Concrete ◽  
Steel Fibre ◽  
The Other ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Compressive Properties ◽  
Shrinkage Cracking ◽  
Steel Fibre Reinforced Concrete ◽  
Expansive Agent ◽  
Concrete Matrix

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.

Effect of Plastic Deformation on Hydrogen Induced Crack Resistance of API X65 Linepipe Steel

2016 ◽  
Vol 54 (4) ◽  
pp. 295-303 ◽  
Author(s):  
Kyung-Mox Cho ◽  
Joon-Ho Sung ◽  
Yun-Kyu Kim ◽  
Jong-Geol Moon ◽  
Ki-Won Kim ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Crack Resistance ◽  
Linepipe Steel

Complex study of the fracture processes in materials and structures

2018 ◽  
Vol 84 (11) ◽  
pp. 46-51 ◽  
Author(s):  
N. A. Makhutov
Keyword(s):  
Fracture Mechanics ◽  
Crack Resistance ◽  
Scientific Basis ◽  
Intensity Factors ◽  
Nonlinear Fracture Mechanics ◽  
Nonlinear Fracture ◽  
Linear Fracture ◽  
Science Technology ◽  
Fracture Processes

The results of comprehensive studies of multifactor processes, mechanisms and criteria for fracture at a variation of the crack-like defect state, loading conditions and mechanical properties of structural materials carried out in the 20th - 21st centuries are presented on the basis of monographic publications and articles published in the journal “Zavodskaya Laboratoriya. Diagnostika Materialov.” Crack resistance of materials and structures has become a key problem of the material science, technology, design, manufacture and service of structures. Fracture mechanics including estimation of the stress-strain and limiting states in a cracks tip formed a scientific basis of the crack resistance analysis Stress intensity factors (linear fracture mechanics) and strain intensity factors (nonlinear fracture mechanics) are accepted as the basic criteria of those states. The basic computational relations for construction of the fracture diagrammes which link the cracks growth with conditions of a static, cyclic, long-term, dynamic loading are presented. Parameters of computational relations are put into correspondence with the features of fracture processes on nano-, micro-, meso- and macrolevels. Prospects of the research and guidelines of further studing crack resistance are discussed.

Analysis of Crack Resistance of Interfaces between Materials

2020 ◽  
Vol 55 (4) ◽  
pp. 536-551
Author(s):  
M. N. Perelmuter
Keyword(s):  
Crack Resistance

TRIBALOY ALLOY T-900

Alloy Digest ◽  
1996 ◽  
Vol 45 (10) ◽  
Keyword(s):  
Wear Resistance ◽  
Crack Resistance ◽  
Base Alloy ◽  
Corrosion And Wear ◽  
Laves Phase ◽  
Preheat Temperature ◽  
Corrosion Resistant ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract Tribaloy alloy T-900 is a cobalt-base alloy derived from an alloy family originally developed by DuPont. Excessive amounts of molybdenum and silicon induce the formatin during solidification of a hard and corrosion-resistant intermetallic coumpound, known as Laves phase. This alloy had improved crack resistance and a lower preheat temperature compared with Tribaloy T-800 (Alloy Digest Co-99, September 1996). This datasheet provides information on composition, microstructure, and hardness. It also includes information on corrosion and wear resistance. Filing Code: CO-100. Producer or source: Stoody Deloro Stellite Inc.

scholarly journals Experimental Research on Crack Resistance of Fiber Asphalt Mixture in Cold Area

2021 ◽  
Vol 791 (1) ◽  
pp. 012072
Author(s):  
Bo Peng ◽  
Shuai Liu ◽  
Wenying Li ◽  
Jingwen Peng ◽  
Yilang Li ◽  
...  
Keyword(s):  
Crack Resistance ◽  
Experimental Research ◽  
Asphalt Mixture ◽  
Cold Area
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