The application of glass textile reinforced cementitious composites (GTRC) in slender building elements such as plates or shells, can be advantageous over the widely used steel-reinforced concrete. As the glass fibre diameter is three orders of magnitude smaller than the typical steel rebar diameter, very thin and/or freeform plates and shells can be designed. In these two-dimensional elements however, complex biaxial stress states can occur under various load combinations. Up to now, only the uniaxial behaviour of GTRC is studied extensively: GTRC behaves approximately linear in compression, but is highly nonlinear in tension. In this paper, biaxial tensile tests are carried out on cruciform GTRC specimens and observed with the Digital Image Correlation technique. Experimental results are described and compared to a numerical model in the finite element program Abaqus. First results show that the uncoupled stress-strain behaviour in both principle stress directions leads to an underestimation of the biaxial stiffness of GTRC.