scholarly journals Model for practical carbonation depth prediction for high volume fly ash concrete and recycled aggregate concrete

2019 ◽  
Vol 213 ◽  
pp. 194-208 ◽  
Author(s):  
Vedran Carević ◽  
Ivan Ignjatović ◽  
Jelena Dragaš
2020 ◽  
Vol 10 (18) ◽  
pp. 6454
Author(s):  
Valeria Corinaldesi ◽  
Jacopo Donnini ◽  
Chiara Giosué ◽  
Alessandra Mobili ◽  
Francesca Tittarelli

The possibility of producing high-volume fly ash (HVFA) recycled aggregate concrete represents an important step towards the development of sustainable building materials. In fact, there is a growing need to reduce the use of non-renewable natural resources and, at the same time, to valorize industrial by-products, such as fly ash, that would otherwise be sent to the landfill. The present experimental work investigates the physical and mechanical properties of concrete by replacing natural aggregates and cement with recycled aggregates and fly ash, respectively. First, the mechanical properties of four different mixtures have been analyzed and compared. Then, the effectiveness of recycled aggregate and fly ash on reducing carbonation and chloride penetration depth has been also evaluated. Finally, the corrosion behavior of the different concrete mixtures, reinforced with either bare or galvanized steel plates, has been evaluated. The results obtained show that high-volume fly ash (HVFA) recycled aggregate concrete can be produced without significative reduction in mechanical properties. Furthermore, the addition of high-volume fly ash and the total replacement of natural aggregates with recycled ones did not modify the corrosion behavior of embedded bare and galvanized steel reinforcement.


2011 ◽  
Vol 261-263 ◽  
pp. 217-222 ◽  
Author(s):  
Fang Tian ◽  
Wei Xin Hu ◽  
He Ming Cheng ◽  
Ya Li Sun

This paper addresses the efficiency of using recycled concrete as an aggregate by systematically presenting results on the influence of fly ash on recycled aggregate concrete (RAC) properties. The percentage of recycled aggregate replacements of natural aggregate used by weight was 50%. Fly ash (FA) was used as 0, 10, 20, 30, and 40% by weight replacement of cement. The results showed that an increase in the W/B decreased the resistance to carbonation depth. Nevertheless, the use of FA as a substitute for cement decreased the carbonation depth of the recycled aggregate concrete. Being analyzed on the basis of Gray Theory, it can be seen that the biggest influence on the depth of carbonation of the recycled aggregate concrete comes from W/B, then the carbonation age and FA content affects the least.


2011 ◽  
Vol 261-263 ◽  
pp. 333-337
Author(s):  
Juan Hong Liu ◽  
Fang Fang Hou ◽  
Shao Min Song ◽  
Bo Ya Jia

In this article, the effects of compressive strength and carbonation depth of HCSA mixing amount on high volume fly ash concrete have been investigated. Besides, the effects of compressive strength and carbonation depth of the fly ash amount on HCSA expansive concrete have been also analyzed. The results show that proper HCSA mixing amount can improve the compressive strength and anti-carbonation resistance. On the condition of 55% mixing amount of fly ash and 6% HCSA, the compressive strength for 28 days enhanced 8MPa, the carbonation depth decreased by 0.7mm, at the age of 70, the strength increased by 12MPa and the depth reduced 1.7mm; when the mixing amount of HCSA reaches 10%, the internal structure of concrete would be destroyed; In the case of 6% HCSA amount, the compressive strength and anti-carbonation resistance decreases with the increase of fly ash mixing amount. While comparing to the concrete without HCSA, the compressive strength and anti-carbonation resistance increase obviously.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 596
Author(s):  
Yasuhiro Dosho

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.


Sign in / Sign up

Export Citation Format

Share Document