| It was learned from foreign media that the US Army Corps of Engineers (USACE) has developed a 3D printed concrete composition technology and obtained a corresponding patent. The concrete composition provides high structural strength for building components.  3D printing has been around for more than 30 years, and with the development of new printable materials, it can be used to build increasingly complex parts and products. USACE is leading the way in developing 3D printing technology that can quickly build military and civilian buildings. However, An important limiting factor in 3D construction projects is the construction of concrete buildings rather than cement construction. Concrete derives its strength due to the presence of 'aggregates' of rock and stone, but concrete is inherently non-uniform, and therefore, concrete can easily clog mechanical equipment. Cement is a homogeneous mixture that does not clog machines, but Does not have the required structural strength, to ensure that it will not collapse under pressure.  As a result, the U.S. Army invented a printable concrete composition consisting of a mixture of solids, water, and various liquids. The solid mixture includes aggregates, grit, binders, and fine sand. Clay Additives, Fly Ash Mixtures, and Silica fume mixture. Aggregates, coarse sand and fine sand are present in a ratio of approximately 1:1:1, while clay admixtures, fly ash admixtures and silica fume admixtures are approximately 1.5%, 10% and 5% ratio exists. This solid mixture can be pre-packaged for subsequent combination with the on-site water and liquid mixture to form a printable concrete composition. Liquid additives include flow control agents, plasticizers, accelerators, and shrinkage reducers. The flow control mixture controls the rheology of the printable concrete composition by changing its tackiness. This improves the flow of the printable concrete composition under high pressure. And pumping. The plasticizer mixture reduces the amount of water used in the printable concrete composition. The shrinkage reducer reduces the cracking and shrinkage of the composition during the drying process, while the accelerator mixture shortens the setting time and increases the strength of the printable concrete composition. .   This new concrete composition can be used to build high-strength building parts by 3D printing technology. Once a printable concrete composition is prepared, the user can print the structure without further modification of the composition. It is possible to embed nets between layers of concrete composition to enhance or stabilize the structure. |
