Speed. Flexibility. Aesthetic.
Precast is a smart, safe and cost-efficient way to build any type of building*. This technology includes precast concrete as a construction product produced by casting concrete in a reusable form which is then cured in a controlled environment, transported to the construction site and lifted into place.
* Australia 108 in Melbourne, AUS is the world’s tallest, total precast skyscraper using Japan-made NMB Splice Sleeve grouted couplers. (www.australia108.com)
Benefits of Precast Technology
Precast Concrete builds upon its very foundation leading towards
versatility, efficiency, and resiliency.
VERSATILITY
From its fluid state in a form to its varied use in and on a structure, precast concrete is adaptable and serves multiple purposes, Whether you value the wide spectrum of colors, textures, and finishes, or rely on its stability, strength, and durability, it all comes down to the versatility of precast concrete construction.
EFFICIENCY
Precast concrete minimizes wasted effort or expense from cradle to grave. From the planning phase, efficient design uses thinner sections: skinny columns, reduced beam sizes, and slim wall panels. In production, precast concrete plant operations use the least amount of labor and materials to meet building specifications. During construction, fewer trades are involved, limiting on-site duration, wasted effort, and cost of financing. The operation of a precast concrete building involves less maintenance and lower insurance costs.
RESILIENCY
A resilient building is one that rolls with the punches. To maximize the
future resilience of buildings, they should be designed for durability, robustness and continuity. Use materials and construction methods that are durable in the face of natural and man-made events. Precast concrete construction is designed to last the test of time.
Source: https://www.pci.org/howprecastbuilds
Total Solution for Owners
This design approach can take several forms, including precast columns and beams with panelized cladding or load-bearing precast walls and double-tee or hollowcore flooring.
- One-stop shopping secures much of the building’s shell in one efficient, contractual relationship.
- The ability to begin fabrication while permitting and site work are completed allow precast concrete to begin erection as soon as foundations are complete.
- Designers find precast systems easier to design, thanks to aid from the precaster’s engineering.
- Precast components can be erected in winter conditions, maintaining tight schedules.
- With total precast systems, speedy erection allows the contractor to enclose the building quickly, giving interior trades faster access.
- Precast’s inherent fire resistance eliminates the messy and time-consuming work of fireproofing a
steel structure and then repairing it as other trades finish
Precast concrete panels offer a wide range of styles and can be produced in a variety of colors, textures and finishes. They can replicate granite, brick or stone, achieving a strong, institutional image at a fraction of the cost.
PCI-certified precast concrete fabricators must undergo two annual, unannounced inspections that review more than 120 production and quality-assurance processes. The tight control ensures components are produced with uniform consistency.
Precast panels require less maintenance than other materials. Incorporating the architecture into the structure enlarges panel sizes, minimizing the number of joints. This significantly reduces the chance for water penetration that can weaken a structure and cause unsightly staining and mold problems.
Because of precast concrete’s tightly controlled and shorter production process, costs can be more accurately estimated earlier in the process. Parallel effort by precast engineering ensures that estimates remain stable, assuring the contractor, owner and design team that the budget is sound.
In-plant casting keeps the site cleaner and eliminates trades from the construction zone, improving logistics and enhancing worker safety. The ability to provide a clean site is particularly vital on existing campuses and in dense urban areas, where adjacent businesses can maintain near-normal activities.
Precast manufacturers support design and coordination efforts as early as half-way into schematics. The precaster can ensure the building takes full advantage of state-of-the-art fabrication and connection techniques. This input allows the project to remain cost-effective and efficiently designed.
Total Solution for Architects
In addition to meeting all of the building owner’s goals, total precast concrete systems provide specific advantages to architects that make the design process smoother.
Precast concrete systems help building owners adapt to changing client needs through the years. Double-tee spans of 45 to 50 feet match typical composite-steel framing and minimize the need for interior columns required with cast-in-place systems. Precast spans can reach as much as 70 feet, providing flexibility for challenging interior requirements. Precast also provides high floor-loading capability with little added cost.
Working in parallel with the precaster can provide early and precise design aid that ensures the most efficient sizes and shapes for components, which minimizes the budget for casting, transporting and erecting pieces. Component repetition reduces form costs and aids design speed while retaining design flexibility. These cost efficiencies free up more of the budget for other critical design areas.
Innovative precasters continue to develop mixes, tints, insets, finishes and multi-color pours, providing an almost endless range of aesthetic options. Virtually any desired appearance can be achieved. The options include natural stone replication, inset brick, multi-color panels, multi-surface textures and special logo, emblem or signage embedments.
Precasters can provide finish samples, range samples and large-scale mockups, ensuring that design concepts translate into reality. Designers can inspect window interfaces, joint connections and other critical elements to ensure they are visually acceptable and will properly interface between trades. Plant visits to discuss technical and aesthetic concerns provide control without requiring constant site supervision.
Precast concrete offers a number of benefits that make it environmentally friendly, a growing need as the Leadership in Energy & Environmental Design (LEED) criteria become more popular. Precast requires fewer chemicals to keep it clean over its long lifetime, and it offers a high thermal mass. It can be produced locally and creates no job waste. Cement reducers such as fly ash and other admixtures also aid its environmental friendliness. And its high durability gives it a total service life that far outpaces designs using other building materials.
Precast concrete systems sometimes fit within alternative system depths but shouldn’t add more than approximately eight inches to each floor level, creating an approximate 5-percent increase in exterior wall material. This slight addition is easily overcome by working with the precaster to make effective use of the overall floor-plan shape and using the benefits precast provides in repetition of component fabrication.
Total Solution for Contractors
General contractors attest that precast concrete components make their job easier at the site. Going total precast ensures a smooth process for the owner and designer in both the short and long term.
Time is money for the entire construction team. Precast concrete’s speed through design, fabrication and erection help meet tight deadlines. This particularly aids contractors when permitting processes slow down or unforeseen delays arise at the site due to soil conditions or other factors. Precast structural systems are ready to be erected when the contractor is prepared.
Contractors can minimize the added “cushion” created in schedules to accommodate bad weather conditions, since precast components can be produced and erected all year round. The roughened surface of precast components does not become slick or difficult to handle in harsh weather as other building materials can.
Total precast systems can minimize foundation work by having sills designed as grade beams and basement walls and core walls designed as precast panels. The components can be fabricated in advance and laid into place as soon as the site is ready.
This messy, time-consuming job can be eliminated, along with the need to patch and rework after other trades finish at the project’s later stages. Precast members are naturally fire protected, because they will not burn.
Because precast concrete pieces are fabricated in controlled conditions using high-quality procedures, designs more exactly meet specifications. Field adjustments thereby are reduced, creating a smooth erection process with minimal surprises.
Total Solution for Engineers
Structural engineers report no difficulty in learning to design with total precast concrete systems. They also benefit from the material’s ease of use and efficiency.
Combining architecture and structure provides efficiencies in many buildings’ lateral support systems. External elements, typically cladding-on-steel or concrete-framing systems, can become laterally stiff and resist wind and earthquake forces. Parallel efforts by the precast engineer can provide the structural engineer with specific input ahead of final construction document preparation, limiting shop-drawing review effort and redesign.
Total precast concrete systems allow the architectural panels to serve structural functions, limiting the need to incorporate multiple materials and trades. For instance, spandrel panels support floor systems and windows while providing final exterior finishes. Or sill panels are used as grade beams, retain soil, support windows and provide the architectural exterior finish, avoiding complex cladding systems. Combining exterior spandrels into the structural system provides deeper elements, limiting deflections and the complexities of designing for relative movements between frame and cladding system. Precast cores support floor systems while providing secure and fire rated enclosures for elevators and stair functions.
A total precast concrete system ensures one-stop shopping for the core/shell design. One source can design and supply the entire system, generating a better coordinated set of drawings that allows construction to proceed more efficiently. It eliminates the added effort needed to coordinate various trades when using mixed systems controlled by different suppliers.
Site construction moves smoothly because no special equipment or techniques are required to transport or lift combined structural and architectural components. These types of activities often can require additional structural review and exposure.
