materials Article First Large Scale Application with Self-Healing Concrete in Belgium: Analysis of the Laboratory Control Tests Tim Van Mullem 1 , Elke Gruyaert 2, Robby Caspeele 1 and Nele De Belie 1,* 1 Magnel-Vandepitte Laboratory, Department of Structural Engineering and Building Materials, Faculty of Engineering and Architecture, Ghent University, Tech Lane Ghent Science Park, Campus A, Technologiepark Zwijnaarde 60, B-9052 Gent, Belgium;
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[email protected] (R.C.) 2 Department of Civil Engineering, KU Leuven, Ghent Technology Campus, Gebroeders De Smetstraat 1, 9000 Ghent, Belgium;
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[email protected]; Tel.: +32-92645522 Received: 21 January 2020; Accepted: 20 February 2020; Published: 23 February 2020 Abstract: Due to the negative impact of construction processes on the environment and a decrease in investments, there is a need for concrete structures to operate longer while maintaining their high performance. Self-healing concrete has the ability to heal itself when it is cracked, thereby protecting the interior matrix as well as the reinforcement steel, resulting in an increased service life. Most research has focused on mortar specimens at lab-scale. Yet, to demonstrate the feasibility of applying self-healing concrete in practice, demonstrators of large-scale applications are necessary. A roof slab of an inspection pit was cast with bacterial self-healing concrete and is now in normal operation. As a bacterial additive to the concrete, a mixture called MUC+, made out of a Mixed Ureolytic Culture together with anaerobic granular bacteria, was added to the concrete during mixing.