Nowadays, there is a growing demand for flexible and dynamic architecture. More and more applications ask for adaptable structures, which are adjustable in a way that they can meet the current needs. Therefore, kinematic lightweight structures offer an excellent solution. These reconfigurable frames with a technical textile cover can offer a great variety of configurations.

The major task in analyzing the structural behavior of Kinematic Form Active Structures (KFAS) is to investigate the stiffness and stability during all phases of deployment. The design and optimization process contains a study of their geometric compatibility, pre-tension and curvature.

The study of the structural response of the membranes in KFAS, forms the main task of the FWO-project “Integrated analysis and experimental verification of Kinematic Form Active Structures (KFAS) for architectural applications”. The project consists of an experimental part, where the feasibility is checked thoroughly, and a numerical part, where an optimization of the numerical models is performed.

Several software packages for the numerical analysis of membrane structures have been developed during the past decades, still incorporating a number of simplifications related to the material characteristics, such as anisotropy, non-linear behavior, crimp interchange, shear and relaxation phenomenon. This hinders a correct analysis and hence results remain insufficiently accurate for the studied KFAS. The experimental results are  here used to validate and optimize the numerical simulation.

Previous research had already demonstrated that the application of externally bonded composite reinforcement on structural concrete elements has a positive influence on the bearing capacity. In the construction industry this type of reinforcements is already supplied by specialized companies. It concerns CFRP’s or Carbon Fibre Reinforced Polymers, where the carbon fibres are embedded in a polymer matrix. At the VUB (Vrije Universiteit Brussel), a cementitious matrix material has been developed, which can be used in combination with glass fibres without deteriorating them. One of the applications of this material (GFR IPC > Glass Fibre Reinforced Inorganic Phosphate Cement) is therefore situated in the field of external reinforcement. Research is still ongoing. The finding that the initial high stiffness of the concrete beam is being maintained till a moment that is significantly higher than the moment where the first cracks appear, demonstrates the positive effects of the external GFR IPC reinforcements.

In this master thesis a thorough study was done on the cracking process of plain concrete beams with an external longitudinal reinforcement. On the one hand, a comparison was made between the CFRP’s, which are already used and the GFR IPC laminates, which are being developed at the VUB. On the other hand, the influence of the positions and composition of the reinforcements were examined more closely. Finally the effect of a precrack was studied by placing a plastic foil while casting the concrete.

Each of these aspects was examined experimentally by means of a series of tests. Additionally, an analytical calculation verified a great amount of the parameters which were studied in the tests.