Proceedings

EPJ B Highlight - Preventing concrete bridges from falling apart

Cement bridges can be degraded by environmental factors. Photo by Simone Hutsch on Unsplash

Concrete degradation from sulfuric acid can be avoided by finding ways of preventing its gas precursor from adsorbing into concrete

Extremes of temperature, rain, exposure to corrosive substances - all of these environmental factors contribute to the degradation of concrete. Specifically, a gas present in our environment, called hydrogen sulphide, turns into sulphuric acid, a corrosive substance, when combined with rainwater. In a new study published in EPJ B, Matthew Lasich from Mangosuthu University of Technology, Durban, South Africa, examines the adverse consequences of the adsorption of natural gas constituents found in our environment - and mixtures of several such gases -into one of the materials that make up concrete: cement hydrate. Lasich found that the preservation of concrete infrastructure from the corrosive effects would require a pre-treatment targeting the adsorption sites in cement hydrate, where the majority of hydrogen sulphide molecules become attached. However, this approach could prove difficult because of their wide distribution.

What makes concrete vulnerable to natural gas adsorption is its porous nature. Its structure is made up of a cement matrix binding together aggregates of particles of sand. In this study, the authors perform a nanoscale analysis based on Monte Carlo simulation to mimic the migration of gas molecules into the cement hydrate structure.

They first recorded the adsorption level across various temperatures for methane, ethane, ethene, and ethyne to determine the uptake of each gas species in cement hydrate. This allowed them to study the effect of molecular size and molecular shape on the sorption of gases in cement hydrate. They then performed a similar analysis for natural gas constituents including nitrogen, carbon dioxide, and, most importantly, hydrogen sulphide.

Their simulations suggest that a specific combination of molecular size and surface area is required for good uptake into cement hydrate. While hydrogen sulphide adsorbed most favourably of all gases considered in this study, ethyne adsorbed more favourably than methane, despite being a 'heavier' molecule, because its molecular shape lent itself better to the task.

M. Lasich (2018), Sorption of natural gas in cement hydrate based on Monte Carlo simulation, European Physical Journal B 91:299, DOI: 10.1140/epjb/e2018-90339-6

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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