Gas chromatography to detect bacteria-based self-healing agents in concrete

¹ Department of Materials & Environment, Faculty of Civil Engineering & Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands
² Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands

^* Corresponding author: e.rossi@tudelft.nl

Abstract

In the concrete industry, legal disputes might occur when a built structure performs worse than it was supposed to during the design phase. When dealing with underperformance of self-healing concrete (e.g., no regain of water tightness after cracking), these disputes might likely be related to questioning if healing agents were actually included in the material or not. In this study, a methodology based on Gas chromatography is proposed to detect and quantify poly-lactic acid based-healing agents in cementitious materials. The applicability of this technique for this purpose has been demonstrated on mortar and concrete powders with and without healing agents. The amount of material needed to conduct the experiment is less than 200 mg, making the technique suitable for on-site application to limit any destructive action as much as possible. The application of gas chromatography to detect and quantify healing agent inclusions in concrete has the potential to be extended to other additives, depending on their composition.