scholarly journals Strength Development and Thermogravimetric Investigation of High-Volume Fly Ash Binders

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3344 ◽  
Author(s):  
Zhiyuan Zhou ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Rackel San Nicolas ◽  
Gideon Hadi Kusuma ◽  
...  

To address sustainability issues by facilitating the use of high-volume fly ash (HVFA) concrete in industry, this paper investigates the early age hydration properties of HVFA binders in concrete and the correlation between hydration properties and compressive strengths of the cement pastes. A new method of calculating the chemically bound water of HVFA binders was used and validated. Fly ash (FA) types used in this study were sourced from Indonesia and Australia for comparison. The water to binder (w/b) ratio was 0.4 and FA replacement levels were 40%, 50% and 60% by weight. Isothermal calorimetry tests were conducted to study the heat of hydration which was further converted to the adiabatic temperature rise. Thermo-gravimetric analysis (TGA) was employed to explore the chemically bound water (WB) of the binders. The results showed that Australian FA pastes had higher heat of hydration, adiabatic temperature rise, WB and compressive strength compared to Indonesian FA pastes. The new method of calculating chemically bound water can be successfully applied to HVFA binders. Linear correlation could be found between the WB and compressive strength.

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Yun-Wang Choi ◽  
Man-Seok Park ◽  
Byung-Keol Choi ◽  
Sung-Rok Oh

In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.


2018 ◽  
Vol 20 (2) ◽  
pp. 51
Author(s):  
Antoni . ◽  
Hendra Surya Wibawa ◽  
Djwantoro Hardjito

This study evaluates the effect of particle size distribution (PSD) of high calcium fly ash on high volume fly ash (HVFA) mortar characteristics. Four PSD variations of high calcium fly ash used were: unclassified fly ash and fly ash passing sieve No. 200, No. 325 and No. 400, respectively. The fly ash replacement ratio of the cementitious material ranged between 50-70%. The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those with fly ash passing mesh No. 325. The increase was found due to better compactability of the mixture. Higher fly ash replacement reduced the mortar’s compressive strength, however, the rate was reduced when finer fly ash particles was used.


2016 ◽  
Vol 705 ◽  
pp. 332-337 ◽  
Author(s):  
Zheng Gang Lu ◽  
Xiu Xin Wang

The hydration evolution of concrete with different water-binder ratios and fly ash replacement percentages are studied by experimental investigation. Based on equivalent age concept, the effect of water-binder ratio as well as fly ash dosage on the ultimate temperature rise and heat release coefficient are analyzed with the hyperbolic-type calculating model of adiabatic temperature rise adopted. It is indicated that the adiabatic temperature rise will be reduced with the increase of water-binder ratio and the incorporation of fly ash. The hydration evolution process will be accelerated with the decrease of water-binder ratio, but slowed down when the amount of fly ash is enhanced.


Author(s):  
Ali M. Onaizi ◽  
Nor Hasanah Abdul Shukor Lim ◽  
Ghasan F. Huseien ◽  
Mugahed Amran ◽  
Chau Khun Ma

Author(s):  
He Tian ◽  
Y. X. Zhang

In this paper, a new green fiber-reinforced cementitious composite containing high volume fly ash and hybrid steel and bagasse fibers is developed. Eco-friendly bagasse fibers from industrial waste and steel fibers are used to improve the mechanical behavior of the new composite, and high-volume fly ash is used to decrease the usage of cement in order to be more environmentally friendly. The influence of the fiber content and fly ash/cement ratio on the mechanical properties of the composite is investigated through the study of the mechanical properties of the new composite, such as compressive strength, modulus of elasticity, and modulus of rupture. It is found that compressive strength, Young's modulus of the composite, decreases with the increase of the fly ash/cement ratio and bagasse fiber content. However, the modulus of rupture of the composite increases firstly with bagasse fiber content, and decreases when bagasse fiber content reaches 3% by volume.


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