LIFT SLAB CONSTRUCTION First Step - Preparing the Panels' Forms Prior to the tilt-up process The first step in creating the tilt-up beginning, the slab is poured to panels is to draw lines on the floor create the floor, where the tilt-up slab where the panels will be panels will be created. formed and poured. Once the lines have been drawn, Ensuring the exact placement of workers place brackets to outline the critical to the success of the where the tilt-up panels' outside project. The tilt-up panels must be boundaries, windows and door sized and positioned in precisely openings will be. the right dimensions and location. forms is Once assembled, the tilt-up panel Workers build the tilt-up panel forms create a jigsaw puzzle forms out of wood connected pattern on the floor slab. But the to the braces. random appearance to the forms' placement is deceiving; each form is positioned precisely to allow the crews to tilt them into their final spot in the coming days. Rebar is placed in the completed rebar is placed in the completed forms. Rebar is a critical forms. Rebar is a critical component of the tilt-up component of the tilt-up construction process. The rebar construction process. The rebar strengthens the tilt-up panels, strengthens the panels, making making them safer to lift into a them safer to lift into a standing standing position and more position and more durable once in durable once in place. place. Workers also position embeds and With the wood forms securely inserts into the tilt-up panels so constructed and the rebar and they will become part of the tilt-up embeds / inserts in place, the panels once the pouring takes tilt-up panels in the photo above place. are ready to be poured with concrete. Second Step - Pouring the Tilt-up Panels Workers pour the cement into the forms in a manner very similar to the way floor slabs are poured. Once the cement has been poured, workers trowel the panels for a smooth, consistent finish. Workers use a variety of equipment, including power trowels, to make sure the panels are level and smooth. These panels will become the exterior (and sometimes interior) walls of the building, necessitating a consistent smoothness or texture on all the panels. The process for building the forms Once the cement has cured, and pouring the panels goes workers remove the wood quickly. An experienced crew can forms and brackets to leave take a large project from bare slab the tilt-up panels lined up on to completed panels in a matter of two weeks. the floor slab. Workers do last minute detail work on the panels, including Thetilt-up panels have been drilling places for the brackets fully prepped and are ready to be connected. to be tilted into place. Third Step - Tilting the Panels into Place The mobile crane lifts the tilt-up The tilt-up panels are poured into panel and tilts it into position forms that provide the exact size, over the footing. The row of shape and door openings to meet panels already in place give the design specifications. The evidence to just how fast the panels can be massive; this tilt- process for putting up tilt-up up panel weighs about 50,000 panels goes. An experienced crew pounds. The largest panel used can tilt up as many as 30 panels a for a tilt-up construction project day. weighed six times as much, over 150 tons. Once the panel is set in place, the crew attaches the braces to The crane lifts the panel and tilts the slab to keep the panel it into position over the footing. standing until it is attached to Workers help to guide the tilt-up the other panels and the roofing panel and keep the braces from system. getting tangled in the lines. Once the panel is set in place, the crew attaches the braces to Workers help to guide a large the slab to keep the panel mobile crane as it lifts a tilt-up standing until it is attached to panel into place on this Fort the other panels and the roofing Worth, Texas warehouse building system. project. SEQUENCE OF LIFTING A 3 STOREY SLAB FOR LIFT SLAB CONSTRUCTION FIXING DETAILS Why do Design / Build Contractors Choose Tilt-up Construction? Tilt-up construction provides numerous advantages over steel buildings or traditional construction for warehouses, call centers, distribution centers, retail stores, office buildings, storage facilities and other types of industrial and commercial projects. A one- to two-story structure larger than 50,000 square feet with less than 50% wall opening space is an excellent candidate for tilt-up construction. But what are the advantages? Savings in Construction Costs - This method of construction uses locally available materials rather than ones that must be manufactured and shipped in. This means that raw material costs are lower, available when needed and less prone to price fluctuations. Tilt-up work crews are typically smaller than the crews used in traditional construction and are normally comprised of local labor. That translates to reduced labor costs. Because of the economies of scale, the larger the footprint for the building, the more these savings improve the project's total cost. Fast Construction Schedule - Erecting the walls with tilt-up panels is faster than building walls using traditional construction techniques. The trades can begin work earlier in the process on a tilt-up project, which allows greater overlapping of project phases. Because the building is made of ready-mix concrete from local sources, the project is less likely to be affected by transportation delays as well. All these factors provide for a faster, more predictable schedule with fewer opportunities for delays and associated cost overruns. Safety - The vast majority of the project takes place on the ground rather than on scaffolding, reducing many of these risks normally faced by workers. Aesthetics - Tilt-up buildings are not prefabricated. Each one is custom- designed for the client's needs and preferences. A full range of building finishes, wall textures and adornments, colors, even curved walls, are available with this method. Tilt-up provides architects and designers with virtually unlimited flexibility in crafting a building that is functional, durable and aesthetically pleasing. The benefits of a project built with tilt-up construction continue long after it is completed: Durability - Tilt-up buildings are extremely durable. Many structures created in the 1940s are still in operation today, with little apparent wear. A testament to the strength of tilt-up construction, general contractors in earthquake-prone California now use this method for 90% of their one-story industrial building projects. Fire Safety - The concrete used in tilt-up panels meets the fire-resistance standards of even the most demanding building codes. For example, a 6.5" concrete wall offers a fire resistance rating of four hours or more. Tilt-up panels are also frequently used in the building's interior as fire walls. Ease of Maintenance - Tilt-up buildings require little in the way of ongoing maintenance, outside of periodic cleaning and repainting as desired. Concrete is impervious to insect or rodent infestation, so this problem becomes a relative non-issue as well. Repairs and Expandability - In the event a wall is damaged by a forklift or truck, damages are typically more localized on a panel than in other types of structures, like steel buildings. Also, the modular design of the panels allows for easier repairs and expansion of the building. Security - Facilities that require positive security and management of the interior environment - prisons, classified manufacturing facilities, businesses with clean rooms - will appreciate the strength and control afforded by concrete and tilt-up buildings. Reduced Insurance Premiums - Because tilt-up buildings have superior fire resistance ratings and have been proven to withstand severe weather and earthquakes, these buildings typically enjoy better insurance rates than steel buildings or other types of structures. Reduced Operating Costs - Concrete provides excellent insulation, reducing the ongoing heating and cooling costs for the tenant. This insulation extends to sound as well as temperature. Workers in a tilt-up office building located in a noisy area will be less affected by the environment. By the same token, a manufacturing business that generates noise will have less effect on its neighbors and will find it easier to comply with local noise ordinances.