Mechanical degradation of ultra-high strength alkali-activated concrete subjected to repeated loading and elevated temperatures

2021 ◽  
Vol 121 ◽  
pp. 104083
Author(s):  
Le Huang ◽  
Jin-Cheng Liu ◽  
Rongjin Cai ◽  
Hailong Ye
Keyword(s):  
Elevated Temperatures ◽  
High Strength ◽  
Repeated Loading ◽  
Mechanical Degradation ◽  
Alkali Activated Concrete ◽  
Alkali Activated

Searching for Durable and Friendly Alkali Activated Concrete for Building Elements Constructions

2015 ◽  
Vol 1098 ◽  
pp. 126-131 ◽  
Author(s):  
Vlastimil Bilek ◽  
Jan Hurta ◽  
Libor Zidek ◽  
Pavel Mec
Keyword(s):  
Building Material ◽  
High Strength ◽  
Good Resistance ◽  
Good Design ◽  
Alkali Activated Concrete ◽  
Alkali Activated ◽  
Building Elements

Alkali activated concrete (AAC) are considered a promising building material. They show high strength, good durability, and good resistance to aggressive agents etc. But these good properties are controlled by the good design of the concretes. The paper presents the results which were recorded for self-compacting AACs with the water to slag ratio 0.50 - 0.52. The resistance of these concretes to Na2SO4, NH4Cl and acetate acid is presented in this paper. These agents were selected because they represent agents which are present in compost or sewage.

Mechanical Characteristics Analysis of Alkali-Activated Fly Ash Cementitious Materials

2010 ◽  
Vol 452-453 ◽  
pp. 721-724
Author(s):  
Gum Sung Ryu ◽  
Hyun Jin Kang ◽  
Su Tae Kang ◽  
Gyung Taek Koh ◽  
Jang Hwa Lee
Keyword(s):  
Fly Ash ◽  
Mechanical Characteristics ◽  
High Strength ◽  
Cementitious Materials ◽  
Molar Concentration ◽  
Basic Study ◽  
Co2 Gas ◽  
Characteristics Analysis ◽  
Alkali Activated Concrete ◽  
Alkali Activated

Recently, research on alkali-activated concrete that does not use cement as binder has been actively conducted. This alkali-activated concrete is a cement zero concrete which, instead of cement, is activated by alkali solution using fly ash known to be rich of Si and Al and enables to reduce effectively the emission of CO2 gas. This paper presents a basic study for the manufacture of cementless concrete using 100% of fly ash. To that goal, the mechanical characteristics of cementless concrete is evaluated according to the age and the variation of the molar concentration of the alkali activator with focus on the identification of the reaction mechanism. The experimental results show that larger molar concentration elutes larger quantities of Si4+ and Al3+. Specifically, approximately twice larger quantities of Si4+ and Al3+ were eluted for molar concentrations of 9M and 12M than 6M. The formation of gel at the surface of fly ash appeared to be caused by the stronger activation of fly ash in higher alkali environment. The resulting compressive strengths per age indicated that the strength of concrete could be controlled according to the molar concentration of NaOH. Moreover, results also demonstrated that a molar concentration of 9M for NaOH seems to be appropriate to secure a strength superior to 40MPa as the reference for high strength concrete in ordinary concrete.

Development of Cementless Fly Ash Based Alkali-Activated Mortar

2009 ◽  
Vol 417-418 ◽  
pp. 721-724 ◽  
Author(s):  
Kyung Taek Koh ◽  
Su Tae Kang ◽  
Gum Sung Ryu ◽  
Hyun Jin Kang ◽  
Jang Hwa Lee
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
High Strength ◽  
Molar Ratio ◽  
Early Age ◽  
Water Curing ◽  
Curing Method ◽  
Alkali Activated Concrete ◽  
Alkali Activated

This study investigates the effects of alkaline activators and curing method on the compressive strength of mortar for the development of cementless alkali-activated concrete using 100% of fly ash as binder. Results reveal that the compressive strength improved according to the increase of the molar concentration of NaOH. In addition, molar ratio Na2O to SiO2 of 1.12 activated the reaction of fly ash with Si and Al constituents and resulted in the most remarkable development of strength. In the case of mortar requiring high strength at early age, higher curing temperatures appeared to be advantages. Curing at 60°C during 48 hours is recommended for requiring high strength at age 28days. Moreover, performing atmospheric curing after high temperature curing appeared to be more effective for the development of strength than water curing. Based on these results, it has been analyzed that alkaline activators fabricated with proportions of 1:1 of 9M NaOH and sodium silicate should be used and that atmospheric curing should be performed after curing at 60°C during 48 hours to produce high strength alkali-activated mortar exhibiting compressive strength of 70MPa at age 28 days.

scholarly journals Alkali-Activated Slag cement: Alternative Adhesives for CFRP Sheets Bonded to Concrete at Elevated Temperatures

2020 ◽  
Vol 23 (3) ◽  
pp. 167-176
Author(s):  
Jing Zhu ◽  
Wenzhong Zheng ◽  
Lili Xie ◽  
Ning Ren ◽  
Yuxuan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Heating Temperature ◽  
High Strength ◽  
Slag Cement ◽  
Alkali Activated Slag ◽  
Cfrp Sheets ◽  
Effects Of Temperature ◽  
Activated Slag ◽  
Alkali Activated

The properties and microstructures of alkali-activated slag cement (AASC) exposed to 20~1200°C were probed in this paper. The aim is to develop an eco-friendly fireproof high-strength adhesive with an optimum ratio and evaluate its usability for CFRP sheets bonded to concrete. The blast furnace slag and fly ash were employed as source materials (activated by potassium silicate, NaOH and Portland cement). The effects of slag content, activator nature and heating temperature on the compressive or bond properties were analyzed. The microstructures of the AASC exposed to different high temperatures were studied by two different techniques, including SEM and XRD analyses. The effects of temperature on the mechanical properties of AASC were first rising then descending, and the basic reason for the degradation of macro-mechanical properties is the deterioration of AASC microstructure. It is proved that AASC has comparable reinforcing effects as those of organic epoxy matrix.

CARLSON ALLOY C600 and C600 ESR

Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Cold Working ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Solid Solution Alloy ◽  
Resistance To Oxidation ◽  
Good Workability

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.

UDIMET 520

Alloy Digest ◽  
1962 ◽  
Vol 11 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Nickel Base

Abstract UDIMET 520 is a nickel-base alloy recommended for applications where high strength at elevated temperatures is required. It is suitable for service at temperatures up to 1800 F. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-74. Producer or source: Special Metals Inc..

RIO TINTO ALLOY 242.2

Alloy Digest ◽  
2020 ◽  
Vol 69 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Elevated Temperatures ◽  
High Strength ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Rio Tinto ◽  
Permanent Mold Castings ◽  
Río Tinto

Abstract Rio Tinto Alloy 242.2 is a heat-treatable, aluminum-copper-magnesium-nickel casting alloy. It is available in the form of ingots to be remelted for the manufacture of sand and permanent mold castings. Alloy 242.0 is used extensively for applications requiring high strength and hardness at elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as casting, machining, and joining. Filing Code: Al-463. Producer or source: Rio Tinto Limited.

IN-102

Alloy Digest ◽  
1969 ◽  
Vol 18 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Iron Alloy ◽  
High Strength ◽  
Heat Treating ◽  
High Ductility ◽  
International Nickel Company ◽  
Nickel Chromium ◽  
Temperature Performance ◽  
High Degree

Abstract IN-102 is a nickel-chromium-iron alloy designed for long service at temperatures up to 1300 F. It combines high strength and high ductility at the elevated temperatures with a high degree of structural stability. It is used for aerospace, power and steam turbine components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-147. Producer or source: International Nickel Company Inc..

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