Effect of Nanosilica on the Strength and Durability of Cold-Bonded Fly Ash Aggregate Concrete

Xiuzhong Peng, Qinghua Wang and Jing Wu ()
Additional contact information
Xiuzhong Peng: School of Civil Engineering, Southeast University, Nanjing 211189, China
Qinghua Wang: College of Construction Engineering, Jilin University, Changchun 130021, China
Jing Wu: College of Construction Engineering, Jilin University, Changchun 130021, China

Sustainability, 2023, vol. 15, issue 21, 1-18

Abstract: Cold-bonded Fly Ash Aggregate (CFAA), as an alternative to natural coarse aggregates, can prepare more lightweight, economical, and sustainable concrete. However, CFAA concrete has insufficient durability, which hinders its application in a salt-corrosion environment. Nanosilica (NS) has an advantage of high activity and is generally used as an efficient mineral admixture in engineering. This study aims to improve the strength and durability of CFAA concrete by incorporating NS. To this end, compression tests, splitting tensile tests, and microscopic analyses were performed to investigate the mechanical properties of the concrete containing different NS dosages. Subsequently, the dry–wet and freeze–thaw durability tests were conducted to evaluate the salt-corrosion resistance and the frost resistance in the water, Na 2 SO 4 solution, and Na 2 CO 3 solution. The results show the compressive and splitting tensile strength peak at 2 wt% NS dosage. In this instance, the concrete has an optimum microstructure and exhibits desirable salt-corrosion resistance in the late stage of dry–wet cycles. During freeze–thaw cycles, NS could improve the frost resistance of the concrete but scarcely diminished internal damage under sulfate attack. The study explores the long-term performance of NS-modified CFAA concrete, providing a simple and effective method to mitigate the concrete deterioration in a harsh environment.

Keywords: cold-bonded; fly ash aggregate concrete; nanosilica; mechanical properties; durability; microstructure (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/21/15413/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/21/15413/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:21:p:15413-:d:1270223

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().