Open Access
ARTICLE
Study on the Durability of Recycled Powder Concrete against Sulfate Attack under Partial Immersion Condition
Hualei Bai1,2, Ying Li1,2,*, Dahu Dai1,2
1
School of Civil Engineering, Qinghai University, Xining, 810016, China
2
Qinghai Provincial Key Laboratory of Energy Saving Building Materials and Engineering Safety, Xining, 810016, China
* Corresponding Author: Ying Li. Email:
(This article belongs to this Special Issue: Recycled Concrete Towards a Sustainable Society)
Journal of Renewable Materials 2022, 10(11), 3059-3078. https://doi.org/10.32604/jrm.2022.020148
Received 06 November 2021; Accepted 24 January 2022; Issue published 29 June 2022
Abstract
In order to make full use of waste recycled fine powder (RFP) in concrete and achieve the goal of carbon neutrality in the concrete industry, the durability of sulfate resistance is an important aspect of evaluating the performance of recycled powder concrete (RPC). Therefore, the durability of RPC under partial sulfate
immersion was studied to provide theoretical guidance for understanding the erosion mechanism of RPC. The
compressive strength, mass loss, and microstructure change patterns of RPC under partial immersion of 5%
Na
2SO
4 and MgSO
4 solutions were analyzed by cubic compressive strength, mass loss rate, SEM-EDS, and
XRD. The results showed that the surface crystalline matter of concrete in Na
2SO
4 solution was mainly white
powders, and that of concrete in MgSO
4 solution was mainly transparent paste, both of which had a little spalling
on the outer surface of the concrete. The compressive strength and mass loss rate of concrete with 20% RFP was
relatively good, indicating that concrete with 20% RFP had better durability against sulfate. The compressive
strength of the lower part of the concrete partially immersed in Na
2SO
4 solution was higher than that of the upper
part and the strength of the lower part of RPC-2 was 3.11% higher than the upper part at 180 d; The pattern was
reversed in the MgSO
4 solution, where the strength of the lower part of RPC-2 was 19.74% lower than the upper
part at 180 d. Microscopic analysis showed that the hydration products of RPC were mainly gypsum and ettringite, while the RPC produced more hydration products with the promotion of magnesium ion in the MgSO
4 solution. The higher the replacement rate of RFP, the more frequent the gypsum-type failures in the concrete.
Keywords
Cite This Article
Bai, H., Li, Y., Dai, D. (2022). Study on the Durability of Recycled Powder Concrete against Sulfate Attack under Partial Immersion Condition.
Journal of Renewable Materials, 10(11), 3059–3078.