Soil-mix walls are subsoil walls, which are constructed by in situ mixing of soil with cement and water. The technique was initially used as a ground improvement technique and is now being developed as construction method for walls with a structural purpose. Currently these walls are reinforced with large steel profiles, which requires a large quantity of steel. Replacing the profiles with bar reinforcement might lead to a decrease in required material quantity and thus a reduction of material costs. There are multiple aspects which influence the possibilities and limitations of bar reinforced soil-mix walls. These include predictability of the material quality, durability and cooperation between soil-mix and the reinforcement. The aim of this project was to contribute to this research by analysing one of the influential aspects. The specific goal of this research project was to analyse the capacity of a reinforcement detail within a soil-mix wall and define the governing failure mechanism. The research combined an experimental and numerical approach to the subject. The critical detail was chosen based on the Huybrechts et al. (2016), Ganne et al. (2010), Dörendahl et al. (2004) and contact with soil-mix experts. To model this detail in a finite element model, in 2D and 3D, material parameters were derived from Denies et al. (2012a), Denies et al. (2014), Denies et al. (2015a) and performed physical tests. The 2D models represented the most critical sections of the detail based on the theoretical stress distribution. The geometrical parameters of the reinforcement design were varified in the models to provide insight in the influence of the design on the capacity. The model results were used to define an preliminary set of design guidelines for the reinforcement cage, related to the depth of the wall. Since only the capacity of the detail is considered, these guidelines are not suficient for a complete design of a bar reinforced soil-mix wall and can only serve as an initial indication. In conclusion, the reinforcement detail is most sensitive to failure due to vertical splitting and has suficient capacity for acceptable wall depths. As stated before there are multiple aspects relevant to the feasibility of bar reinforced soil-mix walls. The predictability of the material quality, the bond with the reinforcement and the durability of the soil-mix strongly influence the final capacity and behaviour of the wall. Therefore it is important to perform further research on these, and other, aspects to conclude on the total structural integrity of an entire bar reinforced soil-mix wall.

Steel fibre reinforced concrete (SFRC) is nowadays used as a construction material for pavement and industrial floors in The Netherlands. The common used SFRC mixture, is concrete strength class C30/37 mixed with circa 35 kg/m3 of steel fibre. The details of the concrete composition mixed with steel fibres are ignored. The mechanical tests result of the experimental program accomplished in this thesis emphasized on the decisive role of the concrete composition and quality on the mechanical properties.