Boron nitride (hBN) enhanced cement based coating 2.0

Purpose and goal:

The objective was to improve the properties compared to a reference paint and be competitive in relation to the industrial reference paint.

The project´s conclusion is that the adhesion improves with the addition of hBN-flakes/fibres but that cement coating of this type, regardless of the addition of hBN flakes/fibres, is not competitive for infrastructure compared to industrial reference coating. Expected results and effects:

The project´s expectation was that the addition of hBN flakes/fibres would increase adhesion and density to protect salt- and climate-exposed concrete infra-structures. Workability equivalent. Adhesion improved with hBN flakes and was better than industrial reference but deteriorated with hBN fibers.

Chloride penetration was slightly improved with cement reference but deteriorated both with hBN flakes/fibres. Carbonation decreased slightly with cement paint regardless of hBN flakes/fibers. Industrial reference decreased much. hBN caused some yellowish stained colour. Approach and implementation:

The project was organized in the ambition of complementary competences; Chalmers for characterization of hBN flakes and fiber, Smart High Tech for production of hBN flakes and fiber, Lanark for production of cement-based coating powder, RISE for laboratory tests. In addition, Akademiska Hus and Göteborgs stad,Trafikkontoret participated for demonstration and follow-up.

Difficulties in manufacturing hBN in a colloidal water solution delayed the project and the demonstration project was simplified. In-depth knowledge needed in the interaction between hBN and cement .