The precast concrete industry has offered quality, economical construction elements for decades. More recently, precast concrete producers have been challenged to maintain their profitability while facing such issues as increasing utility rates, more expensive and scarce skilled labor, and rising material and equipment costs.

Based on a new technology developed by Master Builders researchers, scientists and concrete experts, the Zero Energy System combines Glenium polymer chemical admixtures, Rheodynamic concrete, and technical expertise to enable precast concrete producers to achieve energy savings in the form of productivity, power, and efficient use of resources.

Energy is more than just the cost of fuel or power required to operate a precast plant — energy refers to total effort expended. In precast operations, electric and fuel power is a form of energy; so are manpower, material usage, and equipment efficiency. Accordingly, the new Zero Energy System has been developed to help precast producers rethink processes in a way that will allow them to achieve energy reductions in multiple aspects.

What are its benefits?

The Zero Energy System is designed to provide significant benefits throughout precast production, developers note, including:

• Concrete mixing — An important aspect of the mixing process to precast producers is quality concrete on a consistent basis. The advanced rheology of Rheodynamic concrete assures thorough concrete mixing, less energy to run mixers, and less wear and maintenance on the mixing equipment.
• Concrete placement — To achieve structural performance, precast elements are designed with steel reinforcement, which is often congested. Precast units commonly have thin sections, complex shapes and intricate surfaces. Flowing concrete and substantial vibration are often required to ensure adequate consolidation to completely and reliably fill the forms and surround the reinforcement. External vibration equipment is expensive to maintain and is damaging to the forming system. The placement rate is also important as it affects the production cycle.
  Because Rheodynamic concrete is self-consolidating without the need for vibration during placement, energy required to operate and maintain vibration systems is dramatically reduced, Master Builders officials contend. Additionally, fewer resources are needed to maintain and repair forms and equipment, saving manpower energy and increasing the life of the forms. The self-consolidating feature also can significantly improve the surface appearance of precast elements, lowering the manpower energy often needed for surface repairs. Due to increased plasticity and controlled rheology, Rheodynamic concrete affords faster placement rates, reducing the production cycle. Additionally, gains in employee safety are achieved by eliminating the hazards and noise associated with vibration.
• Curing — Producers strive to accelerate strength development in an effort to reduce cycle times and improve productivity. The goal is to develop sufficient strength to allow cutting of tendons or removal from forms as early as possible without sacrificing the durability and aesthetics of the precast element. Many precast concrete producers use steam or heat curing to facilitate this early strength gain.
  The Glenium HRWR admixture provides opportunities to eliminate or reduce the accelerated heat-curing requirements in precast production. With the Zero Energy System, developers note, the cement hydration kinetics are accelerated from the very early stages, releasing enough heat during the hydration process that the mix is able to self-accelerate the crystal formation reaction, positively impacting early strength development. This system, which can include an activator when casting in extremely low temperatures, will allow a precast operation to maintain regular production cycles of 14 to 18 hours without steam or heat, even in temperatures of 45° to 60°F (8° to 15°C).
• Demolding and handling — Specific minimum strengths are required before precast pieces can be removed from the mold and transported off the production floor. The sooner forms can be returned to production, the more potentially profitable the operation. Early strength gain of the precast allows fast turnaround and reduced cycle times.
  The Glenium HRWR admixture imparts early strengths allowing shorter production cycles and permitting the precast producer to cost-effectively schedule equipment and manpower.