To prove that the GCCM (geosynthetic cementitious composite mat) – type Concrete Canvas (CC) – is an adequate supplementary layer on the top of the subgrade. As its drainage function is known, this article tries to prove the reinforcement possibility. This layer is relatively thin; nevertheless, it can behave like the geogrids. It is the main path to finding out the opportunity of the interlocking effect and its impact on the railway ballast’s inner shear resistance. Methodology. The laboratory measurements were performed in a multilevel shear box, which allows simulating the multilevel shift of the ballast layer. The tests were planned with and without the CC layer. After shearing, the samples were also tested for loadbearing capacity (E2; according to the Hungarian Standard) and particle breakage. On the other hand, the contact surface between the lowest part of the ballast and CC was also measured by a sophisticated 3D laser scanner (GOM ATOS) and graphically by AutoCAD software. Findings. After the results of the laboratory experiments are analyzed, the following parameters are calculated and determined: 1) the reinforcement ratio as the tangent of the inner shear resistance curves in the 5–15 mm horizontal shearing interval as well as the area under graphs by integration in the 0–40 mm interval; 2) the change in loadbearing capacity of the layerstructure with and without CC; 3) the amount of the cement particles; 4) the amount of the broken particles; 5) contact surface between the lowest layer of ballast and CC; 6) flatness of CC sheets after shearing. Based on the results, the Concrete Canvas provides significant reinforcement to the railway ballast. Originality. Any other type of measurement with Concrete Canvas in a multilevel shear box is unknown. The topic is unique. Practical value. In the future, these results may provide baseline data to verify the suitability of the Concrete Canvas in the railway sub or superstructure for various types of transport.