scholarly journals THE INFLUENCE OF DIFFERENT CURING CONDITIONS ON HVFAC RHEOLOGICAL AND MECHANICAL PROPERTIES

Author(s):  
Vedran Carević ◽  
Jelena S. Dragaš ◽  
Aleksandar Radević ◽  
Dragica Jevtić ◽  
Dimitrije Zakić

This research was conducted in order to evaluate the influence of different curing conditions on rheological and mechanical properties of high volume fly ash concrete (HVFAC) in comparison with the ordinary Portland cement concrete (OPC). Four types of concrete were made: two HVFAC and two OPC designed to have the same consistency and 28-day compressive strength for samples cured in water. Also, three different curing regimes were chosen: standard water curing (W), standard laboratory air curing (L) and curing in standard laboratory conditions using curing compound based on the polyolefin emulsion (C). The main objectives were to evaluate the influence of these curing regimes on the compressive strength, flexural tensile strength, modulus of elasticity development over time, water permeability of concrete and concrete shrinkage. The use of curing compound improved previously mentioned properties in some extent compared with the samples cured in standard air conditions.

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.


2010 ◽  
Vol 113-116 ◽  
pp. 1293-1296
Author(s):  
Yu Zhu ◽  
Ying Zi Yang ◽  
Hong Wei Deng ◽  
Yan Yao

In order to investigate the mechanical properties of cementitious composites (ECC) cured at 60°C, four-point bending test and compressive strength test are employed to analyze the effect of fly ash on the properties of ECC. The replacement ratio of cement with fly ash is 50%, 70% and 80%, respectively. The test results indicate that ECC with high volume fly ash still remain the characteristic of pseudo-strain hardening and the deflection of ECC increases remarkably by adding more fly ash. The observations of ECC indicate that the crack width is relatively smaller for higher volume fly ash ECC. Meanwhile, compressive strength of ECC specimens with 80% fly ash can reach to 70MPa. This is helpful to produce precast ECC with high volume of fly ash.


2013 ◽  
Vol 438-439 ◽  
pp. 275-279 ◽  
Author(s):  
He Tian ◽  
Yi Xia Zhang

In this paper, a new green hybrid fibre-reinforced cementitious composite with high volume fly ash and steel and bagasse fibres is developed. High volume fly ash is used to partly replace cement and make the composite greener. Eco-friendly bagasse fibres from industrial waste and steel fibres are utilized to improve the mechanical behavior. In particularly, the influence of the parameters such as the sand/cement ratio and fly ash/cement ratio on the mechanical properties of the composite is investidated by evaluating the essential mechanical properties such as compressive strength and modulus of elasticity. The new green composite is found to be sustainable with high compressive. It is found that compressive strength of the composite decreases while the Young's modulus increases with the increase of the sand content, and that compressive strength and Youngs modulus of the composite decreases with the increase of the fly ash content.


2021 ◽  
pp. 1-29
Author(s):  
Himabindu Myadaraboina ◽  
David Law ◽  
Indubhushan Patanikuni

The incorporation of high volume fly ash, up to 80%, in concrete without compromising the mechanical and durability properties is potentially very advantageous to the concrete industry in enabling the delivery of economic, social and environmental benefits. To assess this, two high volume fly ash mix designs incorporating 80% class F ultra-fine fly ash, known as microash and hydrated lime, with 10% silica fume and 0 % silica fume have been investigated. Properties investigated are compressive strength, carbonation, chloride ion penetration, water absorption and permeability. The specimens were cured for a maximum period of 90 days to optimize completion of the hydration reaction. The results show that the concrete manufactured with 80% microash exhibited compressive strength in excess of 40 MPa at 28 days and over 70 MPa at 90 days. The material also displayed excellent durability properties compared to the normal Portland cement concrete and other high volume fly ash concretes. The addition of silica fume improved the strength and durability properties of the material.


2002 ◽  
Vol 16 (6) ◽  
pp. 353-363 ◽  
Author(s):  
J Mirza ◽  
M.S Mirza ◽  
V Roy ◽  
K Saleh

2014 ◽  
Vol 51 ◽  
pp. 278-286 ◽  
Author(s):  
Steve W.M. Supit ◽  
Faiz U.A. Shaikh ◽  
Prabir K. Sarker

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.


2021 ◽  
Vol 2109 (1) ◽  
pp. 012019
Author(s):  
Xuelian Yuan ◽  
Jie Hu

Abstract Through using cube resisting compression test, fracture properties and micro-structure, the mechanical properties of high volume ground slag concrete under low temperature are studied in this paper. The results show that low temperature can improve the compressive strength of high volume ground slag concrete. And strength increased with the decreased of temperature. Low temperature can also improve the fracture energy and fracture toughness. Not only can ground slag reduce the content of calcium hydroxide in hardened cement paste, but ground slag can improve the compactness of hardened cement paste, reduce porosity and improve the strength of the interface.


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