During this period, design theory also has new development. Since the 1970s, structural reliability theory has gradually stepped into the stage of engineering practical on the basis of mathematical statistics small precast concrete mixers, which makes the limit design method more improved and scientific. In the meantime, structure calculation theory of reinforced concrete gets great development and is widely used in the designs of plate, continuous beam and frame.Henan Daswell Machinery is a professional manufacturer of construction machine for almost 30 years in China. We are dedicated to supplying our customers with best service and products, our major products include:concrete block making machine,SICOMA Twin Shaft Concrete Mixer,If you are interested in our products, please contact us freely: firstname.lastname@example.org Due to the continuous improvement of material strength, the application scope reinforced concrete and prestressed concrete is expanding. In recent 30 years, reinforced concrete and prestressed concrete have achieved remarkable development in long-span structure and high-rise building structure. For instance Concrete Batching Plant without Mixer, Germany builds a roof beam of hangar with scope of 90m by adopting prestressed lightweight concrete; the scope of bridge in Japan reaches 239 m. Currently SICOMA Twin Shaft Compulsory Mixers, the strength of common used concrete is 20一40 N／mm. It is not difficult to produce the concrete of 80一100 N／mm if necessary. In order to lighten self-weight, concrete with light weight but high strength gets big development.