Journal
CONSTRUCTION AND BUILDING MATERIALS
Volume 274, Issue -, Pages -Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.conbuildmat.2020.121780
Keywords
Coral aggregate; Surface treatment; Acetic acid; Geopolymer; Pre-coating
Categories
Funding
- National Natural Science Foundation of China [51778003]
- Key Research and Development Projects of Anhui Province [202004b11020033]
Ask authors/readers for more resources
The use of low concentration acetic acid for pretreating coral aggregates enhanced the strength of coral aggregate concrete when Portland cement was used as binder. Geopolymer coral aggregate concrete was prepared, showing promise as a material for marine environments. By combining gentle acid-wash cleaning and pre-coating of coral aggregate, high-strength CAGC with compressive strength up to 60 MPa at 28-day was successfully manufactured to meet offshore construction requirements.
The coral reef fractures could be potentially used as aggregates for marine infrastructure construction, providing an alternative option to the high-cost gravel and sand aggregates. Coral aggregates are rough, porous and of low strength, which have a weak layer of minerals and microorganisms on the surface and a proportion of quartz inside pores. In the present study, using low concentration of acetic acid to pretreat coral aggregate was proposed to enhance the interface binding. When Portland cement was used as binder, the flexural and compressive strengths of cleaned coral aggregate concrete increased by 22.5% and 7.3%, respectively. Furthermore, the coral aggregate geopolymer concrete (CAGC) was prepared, given geopolymer acts as a strong binding and low porosity matrix, which is a promising material for the marine environment. To manufacture high-strength CAGC, a combined treatment method by gentle acid-wash cleaning and pre-coating of coral aggregate was proposed. The results showed that the mass loss rate of coral aggregate increased with the increase of acetic acid concentration and soaking time; the release of CO2 gas was helpful to remove the embedded sediment particles from the coral aggregates. Excessive acetic acid concentration and prolonged soaking time have adverse effects on the mechanical properties of CAGC, which was attributed to the corrosion of the internal skeleton of coral aggregate and the increase of connected pores. By using the gentle acid-wash and pre-coating method, a high-strength CAGC with compressive strength up to 60 MPa at 28-day was successfully manufactured, meeting the mechanical requirements of the most offshore construction requirements. (C) 2020 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available