The production of double curved shells using conventional building methods with double curved formwork and falsework is very expensive. So why use a double curved concrete shell as supporting structure? When a favorable shape is chosen, a membrane state of stress in the concrete shell can be reached and large spans can be covered with minimal thickness of the concrete without using columns. While conventional slabon- beam structures can be built with a span-to-effective-depth ratio of 8 to 25, the same ratio is much higher for shells (up to 400). This PhD-thesis consists of an introductory chapter and three papers. A new shell construction method for building double curved shells with a high accuracy and thus saving material and man-hours, is presented. The idea is to build double curved concrete shells out of flat hardened concrete plates using pneumatic formwork and pneumatic wedges. The introduction gives an overview about the specific requirements of the scientific work, the aims, the methodology and state-of-the-art of shell construction methods. Additionally, the form finding process, the optimization of the construction method and the choice of reinforcement are discussed. The three papers are then summarized, an outlook for a first practical application of the building method is given and finally further possible research activities on this topic are presented. In the first part of each paper an overview about the state-of-the-art of shell construction methods is given and current newly invented construction methods are mentioned. The second part of each paper explains the functionality of -Pneumatic Forming of Hardened Concrete- (PFHC). In the first paper: Herstellung von Schalentragwerken aus Beton mit der "Pneumatic Wedge Method" - Ein neues Bauverfahren für den Bau von zweifach gekrümmten Betonflächen , a first preliminary bending test series for the determination of the maximum achievable deflection of rectangular concrete slabs is described. The main part of the paper focuses on the erection of a spherical prototype concrete shell with a diameter of 10.8m and a height of 3.3m. In the final part, results of the large scale experiment, accompanying calculations for the distortion and calculations on the finished structure are explained. The second paper: Application areas for pneumatic forming of concrete , mainly deals with the definition of boundary conditions for the use of the building method "Pneumatic Forming of Concrete". In particular, analytically describable concrete shells and free formed concrete shells are analyzed. Afterwards the preliminary experiments and the large scale experiment on a spherical shell are described. Furthermore, the lifting process of concrete shells is subdivided in different parts and is explained with the help of calculations. The final part defines a relation between the thickness of a concrete plate, the maximal achievable curvature and the forces occurring during the bending process. Each of the single curved concrete elements is bent respectively during the transformation process. A proposal for two different methods of connecting the elements after the erection of the shell is made, and the results of joint-tension-tests are presented. Finally different application areas for the building method are explained and shown in form of photorealistic renderings. The third paper: Pneumatic forming of hardened concrete - building shells in the 21st century , presents the erection of a free formed prototype concrete shell with a thickness of 50mm, a length of 17.6m, a width of 10.8m and a height of 2.9m. At the beginning a further optimization of the concrete-reinforcement-combination determined by Finite-Element-calculations, centric-tension-tests, four-point-bending tests and bonding tests is presented. The design of the large scale experiment, the transformation process and the final results are discussed in the main part of the paper. In conclusion, possible applications of "Pneumatic Forming of Hardened Concrete" are shown in form of partial demolitions of the large scale experiment and further visualizations.