Compressive Strength and Drying Shrinkage of Alkali-activated Fly Ash/Slag Mortars

2020 ◽  
pp. 161-164
Author(s):  
Maochieh Chi ◽  
Weichung Yeih ◽  
Jiangjhy Chang ◽  
Kuochung Tsou
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
Alkali Activated

scholarly journals Effects of the alkaline solution/binder ratio and curing condition on the mechanical properties of alkali-activated fly ash mortars

2017 ◽  
Vol 24 (5) ◽  
pp. 773-782
Author(s):  
Maochieh Chi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Alkaline Solution ◽  
Drying Shrinkage ◽  
Strength Development ◽  
Initial Surface ◽  
Binder Ratio ◽  
Curing Condition ◽  
Alkali Activated

AbstractThe study investigates the effects of the alkaline solution/binder ratio and the curing condition on the mechanical properties of alkali-activated fly ash (AAFA) mortars. Class F fly ash was used as the raw material, and sodium hydroxide and liquid sodium silicate were used for the preparation of alkaline activators. Three alkaline solution-to-binder ratios (0.35, 0.5, and 0.65) and four different initial curing conditions (curing in air at ambient temperature for 24 h, 30°C for 24 h, 65°C for 12 h, and 85°C for 6 h) were considered. Test results show that AAFA mortars with alkaline solution-to-binder ratio of 0.35 had higher compressive strength, lower drying shrinkage, lower water absorption, and lower initial surface absorption rate than the other mortars. Furthermore, the curing condition influenced the compressive strength development and drying shrinkage of AAFA mortars at early ages. AAFA mortars cured at 65°C for 12 h appeared to have superior mechanical properties. XRD demonstrates that the hydration products of AAFA mortars are mainly amorphous alkaline aluminosilicate gel, which attributed to the compressive strength. Consequently, the alkaline solution-to-binder ratio significantly affects more the mechanical properties than the curing condition based on the presented results.

scholarly journals Effect of Fly Ash on Compressive Strength, Drying Shrinkage, and Carbonation Depth of Mortar with Ferronickel-Slag Powder

2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Bituminous Coal ◽  
Raw Materials ◽  
Drying Shrinkage ◽  
The Other ◽  
Test Results ◽  
Slag Powder ◽  
Ferronickel Slag

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.

scholarly journals Effect of CaSO4 Incorporation on Pore Structure and Drying Shrinkage of Alkali-Activated Binders

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1673 ◽  
Author(s):  
Hyeongmin Son ◽  
Sol Moi Park ◽  
Joon Ho Seo ◽  
Haeng Ki Lee
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Drying Shrinkage ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Activated Slag ◽  
Capillary Tension ◽  
Alkali Activated Binders ◽  
Internal Pore Structure ◽  
Alkali Activated

This present study investigates the effects of CaSO4 incorporation on the pore structure and drying shrinkage of alkali-activated slag and fly ash. The slag and fly ash were activated at a 5:5 ratio by weighing with a sodium silicate. Thereafter, 0%, 5%, 10%, and 15% of CaSO4 were incorporated to investigate the changes in phase formation and internal pore structure. X-Ray Diffraction (XRD), thermogravimetry (TG)/derivative thermogravimetry (DTG), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), and drying shrinkage tests were carried out to find the correlation between the pore structure and drying shrinkage of the specimens. The results showed that CaSO4 incorporation increased the formation of thenardite, and these phase changes affected the pore structure of the activated fly ash and slag. The increase in the CaSO4 content increased the pore distribution in the mesopore. As a result, the capillary tension and drying shrinkage decreased.

Experimental Study on Alkali-Activated Slag-Lithium Slag-Fly Ash Environmental Concrete

2011 ◽  
Vol 287-290 ◽  
pp. 1237-1240
Author(s):  
Lan Fang Zhang ◽  
Rui Yan Wang
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Alkali Activated Slag ◽  
Percent Increase ◽  
Compressive Strength Of Concrete ◽  
Activated Slag ◽  
Lithium Slag ◽  
Alkali Activated

The aim of this paper is to study the influence of lithium-slag and fly ash on the workability , setting time and compressive strength of alkali-activated slag concrete. The results indicate that lithium-slag and fly-ash can ameliorate the workability, setting time and improve the compressive strength of alkali-activated slag concrete，and when 40% or 60% slag was replaced by lithium-slag or fly-ash, above 10 percent increase in 28-day compressive strength of concrete were obtained.

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