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Concrete is the most used construction material for years. However long term serviceability is an issue, when we focus on sustainable building and use of materials. In long term service different types of visual and structural defects can appear in concrete structures. Defects in material enhances due to aggressive factors in outdoor (chlorides, sulphides and carbonates, freeze-thaw) which reduces material properties over a longer period. Mainly defects on visible surfaces of structures are from mechanical impacts, environmental exposure or due to impropriate maintenance. There are methods to reduce the risks and improve service life. One of them is self-healing materials, like bacteria, crystalline additives, in-capsulated healing agents and other. Use of self-healing material has preference, like lower maintenance costs for inspection, monitoring and complicated repair. Crystalline admixtures have several advantages comparing to other self-healing techniques, like improved concrete water tightness, no need for encapsulation before addition to concrete mix, which reduces sample preparation time.

By using a solvent-based method composites of ethylenevinyl acetate copolymer and carbon black (EVA–CB) were synthesized for sensing BTEX (benzene, toluene, ethylbenzene and xylene) vapours. The composites were characterized using atomic force microscopy (AFM) in an electroconductive mode. Gas sensing results show that EVA-CB can reproducibly detect BTEX and that the response increases linearly with vapour concentration. Compared to gas-sensing measurements of gasoline vapours, the responses with toluene and ethylbenzene are different and can be explained by varying side chains of the benzene ring.