a concrete truss screed is a piece of equipment used to level and consolidate large areas of wet concrete, while double b is likely a reference to the design-bid-build (DBB) project delivery method. Concrete truss screed A truss screed is a specialized power tool used for accurately striking off and smoothing large concrete slabs, such as those used for bridge decks, industrial floors, or roadways. Key features and functions include: Structure: Made of modular aluminum or steel truss sections that connect to form a single, long, and rigid beam. The truss design prevents sagging over wide spans to ensure a perfectly flat and uniform surface. Operation: A vibratory motor on the truss vibrates the beam, which serves two purposes: It helps to compact the concrete, removing trapped air pockets and minimizing the need for manual vibrators. It assists in creating a smooth, level finish as the beam strikes off excess concrete. Applications: It is primarily used for large-scale concrete pours that require a high degree of flatness, known as 'high tolerance FL numbers' in the industry. Versatility: The modular nature of the truss allows it to be adjusted to different widths, making it suitable for a variety of projects. Double b (DBB) In the construction industry, DBB stands for the design-bid-build project delivery method. It is the most traditional approach to construction and follows a linear, sequential process. The method is executed in three distinct phases: Design: The project owner hires an architect or engineer to create a complete set of construction documents, including drawings and specifications. The contractor is not involved during this phase. Bid: After the design is finalized, the project is put out for bid. General contractors review the documents and submit their cost proposals for completing the project. Build: The owner awards the project contract, typically to the lowest qualified bidder. The selected general contractor then manages and oversees the construction based on the completed design. Ready Available In Sadar Nagpur