Comparative study of capillary rise characteristics of saltwater in loose materials

Abstract

Salt in groundwater is brought up by capillary action, and can penetrate into the infrastructure of any building or structure within its reach. This leads to the destruction of these structures, thus reducing their functionality and lifespan. It is crucial to find a suitable, low-cost material that is resistant to saltwater capillary action, in order to support the design of anti-capillary structures. This work involves an experimentally-comparative study on the capillary characteristics of three primary types of loose material, including natural gravel-sand, granulated blast furnace slag (GBFS), and coal bottom ash (CBA). The results obtained indicate that the capillary height of GBFS is the smallest, and that of natural materials is the largest. The salt concentration of the capillary solution is inversely-related to its height. Nevertheless, that relationship does not tend to be linear, but develops into three stages. It takes a relatively longer time to reach a relatively stable capillary rise with CBA compared to natural materials and GBFS. The results suggest that CBA is the most suitable anti-capillary material among the three aforementioned materials, but they must all be greater than 2.0 mm and have a homogeneous particle size.

Keywords:

• Capillary rise
• anti-capillary
• saltwater
• loose materials
• GBFS
• coal bottom ash

Acknowledgements

This research was funded by Vietnam National University, Hanoi, under grant number QG. 18.15, “Influence of saline intrusion on civil construction foundation on soft soil and proposing the countermeasures against its impact in Hai phong coastal zone”.

Disclosure statement

No potential conflict of interest was reported by the authors.