Republic of the Philippines

NUEVA ECIJA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Sumacab Este, Cabanatuan City Nueva Ecija

COLLEGE OF ARCHITECTURE

Tilt-up Construction

Prepared by:Jendel M. Manahan

AR 4-A

Prepared to:Arch. Lexphil John Ragel

Professor

TILT-UP CONSTRUCTION

Tilt-up, tilt-slab or tilt-wall is a type of building and a construction technique using concrete. Though it is a cost-effective technique with a shorter completion time, poor performance in earthquakes has mandated significant seismic retrofit requirements in older buildings.

Tilt-up construction is a special form of precast concrete construction. The technique is used for constructing buildings by prefabricating concrete wall sections (panels) in a horizontal position on either the building's floor slab or on a temporary casting slab. Once the wall sections have cured, they are tilted to a vertical position using a mobile crane, they are temporarily braced in their final upright position, and finally, they are tied into the building's roof and floor system to become an integral part of the finished structure. Tilt-up is a fast, simple, and economical technique of construction which, in the past, has been used most commonly on one-story buildings. Today, however, buildings as high as six stories are being cast and tilted into position.

Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and lifted into place.

History of Tilt-up Construction

Robert H. Aiken- father of “Tilt-Up Construction”

In 1907, Robert Hunter Aiken (1859 - 1925) of Winthrop Harbor, Illinois invented "tilt-up construction.“ Aiken came up with his idea of constructing buildings using pre-cast concrete walls and raising them into position in early 1907, when he built concrete target walls for use at Camp Logan. The new concrete targets kept ordinance from being shot into Lake Michigan and endangering boaters, and allowed the lead to be retrieved and reused.

Typical Uses for Tilt-up Buildings

Tilt-up construction can be used for any type of low- to mid-rise building.

The most common applications are found in warehouses. Warehouse buildings are typically 22 to 30 feet high(7-9m), they are rectangular in shape, and they have a large floor area.

Commercial and industrial offices, shops, warehouses and factories

Recreational buildings sports halls, churches and cinemas

Housing and hotels

Other structures prisons, retaining walls, laboratories, plant rooms, fire-walls, silos and tanks

TILT-UP CONSTRUCTION PROCEDURE

Step 1 Slab Preparation

Slab is thoroughly cleaned.All construction joints are filled to ensure a clean and smooth impression.

Step 2 Layout and Dimension

Guidelines are snapped on the slab to mark the locations of panel dividers, rustifications and block-outs.

Step 3 Adhesive is applied to materials

Special contact adhesive is applied to both the object and the slab, and left to dry.

Step 4 Lay Down

Materials are laid down on the slab and pressure is applied to activate the adhesive. Process is repeated for each element rustification, edge forms, divider forms and block-outs

Step 5 Bondbreaker is Applied

At least 3 coats of Bondbreaker is applied to ensure total separation of the panel from the slab on erection day.

Step 6 Form Lumber is applied to the glue downs

Concrete forms are attached to the glue down blocks to make the panel form.

Step 7 Reinforcing Steel is Installed

Step 8 Install Accessories

Lifting anchors, beam pockets, embedded items and conduit sleeves are placed and tied into the forms and reinforcing steel.

Step 9 Pour and Finish Panels

Concrete is pumped into the panels and spread. Panel is then finished to customers specifications.

Step 10 Remove Forms

Forms are removed behind the concrete finishers. Lifting inserts and other imbedded items are located.

Step 11 Erection Day

Panel is rigged and raised just enough to separate from the slab. Inspection is made and erection continues. As panel is slowly raised it begins to tilt into the upright position. Finally the panel is set in place, and braces are attached to temporarily secure in the upright position. Panel is then shimmed and leveled to the strictest of tolerances.

Step 12 Base of panels are secured

Depending on design, the base of the panels are connected to the footing, plates connecting the panels are welded and the sills are filled with grout.

Step 13 Panels are finished

Panels are ground and patched to ensure a smooth finish ready for paint.

Advantages of Tilt-up Construction

• Simplicity and speed of construction.

• Compared to other forms of precast concrete construction, tilt-up eliminates the need for expensive transportation of building components from the precast plant to the job-site.

• By casting panels at the project site, panels can be designed much larger than those that must be transported from a precast concrete plant.

• Tilt-up construction allows building designers to take advantage of the insulating nature of concrete, while minimizing the labor and energy needed to install such sizable wall panels.

• The system also improves efficiency of the process as a whole. Wall panels can go up while the rest of the project is still undergoing refinement, using fewer steps than older brick-and-mortar methods.

• There is no expensive vertical formwork, and the formwork that is required is accomplished quickly and safely since the carpenters and steelworkers can work at ground level.

• Tilt-up buildings are inherently low maintenance since the concrete surfaces can be left unpainted and are not affected by moisture or weathering.

• Although the typical early generation tilt-up buildings tended to be simple and plain boxlike structures, today's tilt-up buildings have a limitless freedom of design for both shape and architectural treatments.

• In fact, it is difficult to tell that many recently constructed buildings are made by using the tilt-up technique.

• Tilt-up buildings can be very flexible since panels can be easily removed and relocated if future building expansions become necessary. Finally, tilt-up panels of 5-1/2 to 6 inches thick have the inherent fire safety rating of concrete buildings and "will provide a fire endurance of two hours or more"

Disadvantages of Tilt-up Construction

• It can be dangerous.  The fact that panels of many tonnes weight are lifted by crane means that quality control and safety measures must be very stringent.

• Partly because of safety issues many proprietary products are required for this type of construction, so set up costs are large. Because of the previous points, tilt up is not suitable for small one off jobs.

• Tilt slab is a fully engineered system, and as such alterations and amendments can not be made on the fly, i.e. change the size or positions of openings without the express approval of the engineer.

• In spite of the fact that tilt up has the possibilities of great design flexibility, the vast majority of jobs are definitely "industrial" in appearance.