A new type of flat glass steel column template that can control the smoothness of the concrete column completely to the “clean water†concrete with the effect, verticality, and roundness within 3 mm was successfully developed at Beijing Urban Construction No. 2 Company. After being put into use, it proves that the work efficiency is nearly 3 times higher than that of the ordinary steel formwork, and the project cost is also greatly reduced, and the construction quality of the project is significantly improved. It is reported that this technology has obtained utility model patents approved by the State Intellectual Property Office.
Flat glass steel column template is the use of unsaturated polyester resin (No. 191) as a cement material, alkali-resistant glass fiber cloth as a framework made of layer by layer, the material itself is light weight, high strength, good toughness, wear resistance and corrosion resistance. The homogeneous material of a closed material with sufficient toughness under the action of external forces from the inside, the material will be subjected to equal tensile stress in its cross-section. Under its effect, the material itself will certainly develop into a standard circular cylinder. According to this theory, there is no need to make circular tyres when making FRP cylindrical stencils. It is only necessary to make a platform according to the circumference of the column of the building structure. The manufacturing method is to form a vertical 40 mm “L†shaped flange at the interface of the template vertically and perpendicularly to the column body. After the two flanges are butted, the No. 191 unsaturated polyester resin cementation material is applied at the interface. Before the cement material is not completely solidified, a 7 mm thick glass steel strip is adhered along the outside of the L-shaped outer flange to strengthen the flange. To fix the template, place a spacer every 100 mm from 5 mm to 100 mm from the lower edge of the template to prevent displacement. They fixed the main ribs of the column with a diameter of 500 mm to 100 mm on the stencil and fixed them with round positioning hoops to solve the problem of easily deforming the columns.
Due to the light weight of the flat FRP cylindrical formwork, only 2 or 3 persons can be used during construction and installation, and almost no mechanical equipment is used.
The technology is applied to the 350 pillars in the underground space development project in the West Area of ​​Zhongguancun. Not only the final molding effect of the pillar concrete is good, but also the verticality and roundness are controlled within 3 mm. The entire pillar has only one vertical seam, and its smoothness Completely achieved the "clean water" concrete effect, and improve work efficiency 2 to 3 times, saving 825 labor, reducing the tower crane occupation, labor costs and other 22.3 million, and each set of flat glass steel column template can be turnover 30 times. This technology is being fully promoted by City Construction II. Last year, this technology was successfully used in the construction of the independent column of Zhongguancun Dinggu Building.