Engineering cost control in material selection

As my country's steel production continues to increase year by year, steel varieties tend to diversify. Various new building materials, such as lightweight thermal insulation wall panels, color-coated profiled steel plates, floor decks, etc., have been continuously developed and promoted. Building steel structures have more room for material selection in the design stage. The choice of materials is different, the direct cost of the project is different, and the total cost is different. Reasonable selection of building materials in the design stage and control of the unit price of materials or engineering quantities are effective ways to control the project cost.

Many, high-rise steel structure building (roof) floor deck: in design, according to the role in the building (roof) structure system, the floor deck can take two forms, namely ① the floor deck is only permanent The formwork generally adopts ordinary galvanized profiled steel plate, which has lower requirements for minimum galvanizing amount and fire resistance time, and is relatively cheap; ②As a formwork during construction, it replaces the tensioned steel bars in the use stage, that is, composite floor slabs. Since the floor deck is considered as a tension bar in the design, its service life must be consistent with the service life of the main steel structure, so its minimum galvanizing amount and fire resistance time are relatively high, and the unilateral price is relatively high.

Steel specifications and materials: Due to the increase in steel varieties, there are more types of components available for structural design. For example, frame columns can adopt hot-rolled H-beams, welded H-beams, spiral welded round steel pipes, welded square steel pipes, and combined cross-sections, and steel beams can take forms such as equal cross-sections and variable cross-sections. The material can be Q235 plain carbon steel or Q345 low alloy steel. High-strength materials should be used as much as possible in the design. For example, the use of Q345 steel can save 15%-25% of steel than the use of Q235 steel, and the saving ratio for tensile or bending components is larger. When designing, choose economical cross-section steel, such as hot-rolled H-section steel, T-section steel, etc. In some cases, the use of hot-rolled H-section steel columns and beams may use slightly more steel than the use of welded H-section steel. However, considering the processing cost and construction schedule, the cost may be more advantageous.