Behavior of alkali-activated slag pastes blended with waste rubber powder under the effect of freeze/thaw cycles and severe sulfate attack

2020 ◽  
Vol 265 ◽  
pp. 120716
Author(s):  
Alaa M. Rashad ◽  
Dina M. Sadek
Keyword(s):  
Sulfate Attack ◽  
Rubber Powder ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Waste Rubber ◽  
Waste Rubber Powder ◽  
Activated Slag ◽  
Alkali Activated

scholarly journals The Durability of One-Part Alkali-Activated Slag-Based Mortars in Different Environments

2020 ◽  
Vol 12 (9) ◽  
pp. 3561 ◽  
Author(s):  
Luigi Coppola ◽  
Denny Coffetti ◽  
Elena Crotti ◽  
Gabriele Gazzaniga ◽  
Tommaso Pastore
Keyword(s):  
Magnesium Sulphate ◽  
Alkali Content ◽  
Freezing And Thawing ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Gypsum Formation ◽  
Binder Ratio ◽  
Activated Slag ◽  
High Alkali ◽  
Alkali Activated

The paper assesses the durability of one-part alkali-activated slag-based mortars (AAS) in different aggressive environments, such as calcium chloride- and magnesium sulphate-rich solutions, in comparison with traditional cementitious mortars at equal water to binder ratio. Moreover, the freezing and thawing resistance was evaluated on mortars manufactured with and without air entraining admixture (AEA). Experimental results indicate that the alkali content is a key parameter for durability of AAS: the higher the alkali content, the higher the resistance in severe conditions. In particular, high-alkali content AAS mortars are characterized by freeze–thaw resistances similar to that of blast furnace cement-based mixtures, but lower than that of Portland cement-mortars while AAS with low activators dosages evidence a very limited resistance in cold environment. The effectiveness of AEA in enhancement of freeze–thaw resistance is confirmed also for AAS mortars. Moreover, AAS mixtures are quasi-immune to expansive calcium oxychloride formation in presence of CaCl2-based deicing salts, but they are very vulnerable to magnesium sulphate attack due to decalcification of C-S-H gel and gypsum formation.

Sulfate attack on alkali-activated slag concrete

2002 ◽  
Vol 32 (2) ◽  
pp. 211-216 ◽  
Author(s):  
T. Bakharev ◽  
J.G. Sanjayan ◽  
Y.-B. Cheng
Keyword(s):  
Sulfate Attack ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

A Preliminary Research on Alkali-Activated Slag Concrete as Tunnel Lining in Severe Frigid Regions

2013 ◽  
Vol 668 ◽  
pp. 65-69 ◽  
Author(s):  
Heng Shu
Keyword(s):  
Frost Damage ◽  
Sem Analysis ◽  
Tunnel Lining ◽  
X Ray Diffraction ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Activated Slag ◽  
Alkali Activated

The main structure materials of tunnel lining are concrete and steel, and the concrete frost damage is a typical degradation phenomenon of the tunnel linings in cold regions. Alkali-activated slag concrete (ASC) has a better freeze-thaw resistance, which can be used for tunnel lining in severe frigid regions. Freeze-thaw resistance, performance mechanism of ASC and microstructure were investigated by freeze-thaw cycle, X-ray diffraction (XRD) and Scanning electron microscope (SEM) analysis. The experimental results show that, ASC has excellent freeze-thaw resistance, and hydration products of ASC are mostly C-S-H, alkaline aluminosilicate. ASC has a good compact degree and uniformity of structure, and its high compressive strength also makes high freeze-thaw resistance. ASC may be selected as tunnel lining production materials in severe frigid regions because of the less reduction in the dynamic elastic modulus and mass loss of concrete.

External sulfate attack on alkali-activated slag

2013 ◽  
Vol 49 ◽  
pp. 31-39 ◽  
Author(s):  
M. Komljenović ◽  
Z. Baščarević ◽  
N. Marjanović ◽  
V. Nikolić
Keyword(s):  
Sulfate Attack ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

scholarly journals Flexural Fatigue Life Reliability of Alkali-Activated Slag Concrete Freeze-Thaw Damage in Cold Areas

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Bin Chen ◽  
Jun Wang
Keyword(s):  
Fatigue Life ◽  
Building Materials ◽  
Fatigue Properties ◽  
Test Results ◽  
Distribution Fitting ◽  
Flexural Fatigue ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Activated Slag ◽  
Alkali Activated

Studying the application of alkali-activated slag concrete for roads in cold areas is of great significance for promoting and developing green building materials. In this study, the effect of freeze-thaw damage on the flexural fatigue properties of alkali-activated slag concrete was studied and the fatigue life of alkali-activated slag concrete with various degrees of damage after freeze-thaw cycles was studied through a three-point flexural test. The results show that the flexural fatigue life decreases with freeze-thaw cycles from 0 to 150 times. Through a distribution fitting test and K-S test results, the flexural fatigue life followed both the two-parameter and three-parameter Weibull distributions. Between them, the three-parameter Weibull distribution fitting had a higher accuracy and better test results. The results of the reliability analysis show that the curves of alkali-activated slag concrete samples with various degrees of freeze-thaw damage for various failure probabilities have good correlation under different stresses, and the correlation correlations were greater than 0.81. The flexural fatigue life of alkali-activated slag concrete samples with various degrees of freeze-thaw damage was more sensitive to freeze-thaw damage under high stresses. It is suggested that the fatigue design of alkali-activated slag concrete should consider the adverse effects of cold areas, and the reliability should be improved accordingly.

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