Sustainable Buildings with Precast / Prestressed Concrete • How can precast concrete be specified and designed into a project to the benefit of the environment and the project’s bottom line.
Sustainable Precast Concrete Sustainable site planning - Eco-designers believe the way to sustainable building lies in long-life, adaptable, low-energy design
High Reflectivity • Light colored precast reduces heat in urban areas • This reduces the amount of electricity for A/C, which reduces smog- improving urban air quality.
Night and Day • Lighting accounts for 25% of annual electricity usage – when combined with reflective precast concrete, efficiency is enhanced • Lighting enhances security, reducing crime.
Cooler communities • Reflective precast concrete can moderate the heat island urban effect. • Improve energy use, reduce greenhouse gases, lower air and water pollution, and enhance sustainable development • White roofs and shade trees have proven to lower the need for a/c
Sustainable Precast Concrete Safeguarding water and water efficiency - summary • The earth’s resources are best conserved if the service life of a building is prolonged, so the durability and longevity of precast concrete make it an ideal choice.
Sustainable Precast Concrete Energy efficiency and renewable energy: • Optimum Energy performance • Renewable resources • Local materials • Environmentally friendly production practices
Energy Efficiency • The additional R-value provided by the insulation and the concrete’s thermal mass combine to provide a high insulating value in a relatively thin and durable panel. • Thermal mass is particularly beneficial in spring and fall in Northeast climate where there are wide fluctuations in temperatures Exterior Wythe Interior Wythe Insulation
Energy Efficiency • Massive walls absorb and retain heat – and this heat is later released = not taken into consideration with R-Values alone. • Dept. of Energy (DOE) factors that influence the effect of thermal mass: • Heat Absorption • Thermal Lag • Lower energy consumption
Energy Consumption • The time lag between peak heating /cooling loads and outside temperature peaks is greater for p/c walls. • Lower peak heating/cooling loads • Less overall energy to maintain same interior temperature.
Thermal Comfort Humidity control in facility • Assisted by HVAC • Preventing moisture formation on interior walls
Sustainable Precast Concrete Energy efficiency and renewable energy: Summary • Anticipating and designing for maintenance/repair; and designing in flexibility for changes in usage can also extend service life.
Sustainable Precast Concrete Conservation of materials and resources: Building reuse • Construction waste management • Resource Reuse • Recycled Content • Local/ regional Materials
Managing the environment • Aggregate quarries are easily re-used. While disruption can be intense, it is closely contained and temporary. • In a few years after closing, quarries can be restored to agriculture, nature reserves, parks.
Renewable Materials • 85% of Precast Concrete is made up of the naturally occurring materials sand and stone. Compared to other materials extraction requires low amounts of energy and they go directly into the finished product.
Local Precast Production Precast Concrete components are most often transported and erected within 200 miles of the plant.
Local Materials • The use of local cements, aggregates, etc. – keeps transportation of raw materials to a minimum.
Re-usable forms • Steel forms are used to cast structural precast products. These forms have a long life span providing thousands of reuses. • Specialty shaped molds are stored for future use.
Reusable Forms • Re-use of forms reduces waste and debris at the job site. • Construction sites are cleaner and neater.
Controlled Environment • Qualified and trained personnel minimize waste every day at the plant • Grey water is often recycled into future mixes
Recycled Materials • Use of fly ash or slag is commonplace • Substitution of PA “firelight” for aggregates
Controlled Environment • Enclosures allow for the recycling of sand or acid used in finishing techniques
Sustainable Precast Concrete Conservation of resources-Summary • Prestressing allows designers to create longer spans, using less material and leading to enhanced flexibility of buildings in their use.
Sustainable Precast Concrete Indoor environmental quality: • Day lighting and Views • Control Contaminant sources • Low Emitting Materials – Concrete emits low or no VOC’s
Indoor Air Quality • Total Precast System buildings “breathe”. • Using precast walls reduces the out-gassing often attributed to other materials.
Indoor Air Quality • Precast Insulated Walls are more energy efficient –they lower the emissions from furnaces. • Precast floors / walls also provide first class sound proofing with typical STC = 50 -55. Even better, precast is vermin proof –eliminating the need for chemical treatments or inhumane traps.
Indoor Air Quality • Because of high thermal mass – more energy efficient – needing less energy to heat and cool. • Less VOC-emitting insulation used
Indoor Air Quality • Because precast concrete is inert – it does not require VOC-based preservatives like wood. Textured interior walls can provide aesthetic alternatives to VOC-emitting paints or wall board
Sustainable Design • Because precast concrete is non-combustible – it does not require additional fire-proofing applications. • Precast structures are built to last for many, many years.
Sustainable Precast Concrete Indoor environmental quality – summary Excellent sound and fire protection and high thermal mass touch on every aspect of sustainable design as well as the important aspect of increased consideration for people’s health and safety
Sustainable Precast Job Sites • Scheduling for efficient, on-time deliveries of precast that minimize vehicular idling time and traffic congestion • Minimized airborne dust and debris • Use of modular systems minimizes construction waste • Education of field personnel to ensure QC
Economic Benefits Competitive first costs • Integrated design = high benefit at low cost by achieving synergies between disciplines and technologies Reduce operating costs • Lower utility costs significantly Optimize life-cycle economic performance Increase building valuation • Decrease vacancy, improve retention Reduce liability
Innovation and Design Process • Innovation in Design • LEED accredited professional
For more Information • Call 1-800-453-4447 • E-mail: firstname.lastname@example.org • Web: www.mapaprecast.org • PCI : www.pci.org