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116 8 LIST OF SUSTAINABLE CONSTRUCTION PRACTICES Table 26 provides the final edited list of the SCPs for inclusion in the Guidebook. This list is an edited version of Table C-2 (in Appendix C) for final publication in the Guidebook. Editing led to further consolidation and the addition of several SCPs discovered in a secondary review of construction practices by the research team.
117 TABLE 26. Final Edited List of SCPs for Inclusion in the Guidebook Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Delivery Project Delivery Method Contractor Input in Design Phase Would let the contractor to come up with innovative solutions for sustainable construction and reduce project duration and cost. Design-Build (DB), General Contractor/Construction Manager (GCCM), and Integrated Project Delivery (IPD) are delivery methods that allow for early contractor involvement. Integrated Approach for Sustainable Construction Integrated Approach for Sustainable Construction is a guideline by FHWA which provides a step-by-step approach for practitioners to integrate sustainability into the planning, design, and construction of the roadway projects. Integrating sustainability from early stages of the project helps project team to find cost-effective sustainable solutions. Early Inclusion of Sustainability Better to pursue sustainability from early concept stage rather than attempt later integration. Project Financing Public Private Partnership (PPP) "A contractual agreement formed between public and private sector partners, allowing more private sector participation than is traditional." Procurement Include Sustainability in Best Value Procurement Best Value Procurement (BVP) is a procurement approach which considers both qualitative and quantitative criteria for selecting project contractors and vendors. Could result in awarding the project to an experienced contractor who could meet projectâs suitability goals with a low cost in a shorter period of time. Life-Cycle Cost in Best Value Procurement Consider the infrastructure cost over its entire life rather than just construction costs. Value Engineering during Procurement: Alternative Technical Concept (ATC) ATC allow the contractor to submit innovative and cost-effective solutions that are equal to or better than the contracting agencyâs supplied basic configurations, project scope, design and/or construction criteria.
118 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Delivery Procurement Sustainable Procurement Rules Hiring local suppliers and service providers, and supporting minority contractor employees and traditionally disadvantaged population are some commonly used sustainable procurement practices. Environmental Product Declaration (EPD) EPD is defined as a declared Life-Cycle Assessment (LCA) for a product and is a form of certification in ISO 14025 standard (ISO 2006c). EPD could help the industry to make better decision on material selection and improve ownerâs sustainability policy and specification. Contracting Value Engineering during Construction: Value Engineering Change Proposals (VECP) Some construction contracts are designed to incentivize the contractor in continuing promote value engineering ideas throughout construction in the form of VE change proposals for approval by the agency. Use of a Sustainability Rating System A sustainability rating system is âa list of sustainability best practices with an associated common metrics. This metric, usually points, is used to quantify each best practice in a common unit.â (FHWA, 2011). Indefinite Delivery / Indefinite Quantity (IDIQ) Contracts IDIQ contracts could streamline construction process where multiple contracts are involved. Sustainability Management Plan Require a sustainability plan (with deliverables) from the contractor in the contract. Project Scheduling Accelerated Construction Can reduce schedule and user delays. Flexible Start Times Allowing the contractor to better allocate its resources could result in more efficient and faster project delivery. Flexible Work Window Allowing the contractor the flexibility to choose the work window could improve the productivity and save time.
119 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Scheduling Full Road Closures Longer but fewer road closures are preferred due to the cost and impact on the general public. Estimating Model-based estimating (BIM) The model-based estimation techniques provide precise quantities of materials through all the project life-cycle phases and are easy to update in case of changes to original design. Use life-cycle costs Consider life-cycle costs rather than just construction costs, may drive material choice during design and impact construction (and constructability). Project Controls & Administration Enhanced Information Technologies (IT) Leverage cloud, mobile, multimedia computing to reduce risk, provide more insight, etc. Geomatics Use geospatial technologies (barcoding, RFID, GIS, GPS) to track location, materials flow. Earthwork Balanced earthwork Enhancing the rate of cut/fill during construction/maintenance in high traffic regions to minimize the disruption to public and to reduce truck trips and associated fuel use and emissions. Trenchless drainage renewal These methods require minimum surface excavation resulting in reduced disruption to traffic, reduced environmental impacts and enhanced safety. Pipe jacking and horizontal earth boring are some of the trenchless drainage installation methods. Ground improvement instead of remove/replace These techniques are employed for construction at locations that are unfeasible for construction. Ground improvement is carried through different kinds of compaction techniques, soil mixing, and using piers and concrete columns among other methods. Aesthetics Economical aesthetic wall design Achieve project aesthetic goals through economic and constructible wall design. Aesthetics are often proposed by contractor and approved by project. Context-sensitive rock slopes Aesthetically pleasing rock slopes that provide stabilization and rockfall protection.
120 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Aesthetics Construction site aesthetics Temporary construction structures (e.g., fences, trailers, cranes) with aesthetic features. Bridges Accelerated bridge construction (ABC) Prefabricating bridge off-site or away from traffic to minimize traffic disruption, improve safety, and improve durability and quality. Geo-synthetic reinforced soil- integrated bridge systems Alternating layers of compacted granular fill material and geo-synthetic reinforcement to provide support to small single span bridges. Segmental concrete Concrete bridges constructed in repetitive pieces that are progressively connected together to form the complete bridge. Pavement General: smoothness specification Specify pavement smoothness because smoother pavements can result in reduced vehicle operating costs and emissions, and may be more durable. General: warranties Use warranties to reduce future risk and incentive quality construction. General: on-site recycling/reuse Paving methods that recycle/reuse existing pavement materials on-site. Asphalt: density Improve density to increase pavement life, and/or streamline methods for measuring density in the field. Asphalt: longitudinal joints Improve longitudinal joint compaction to reduce the risk of early pavement failure on longitudinal joints. Asphalt: eliminate agg. segregation Eliminate the separation of coarse and fine aggregate in the paving process that can lead to early pavement failure. Asphalt: eliminate density differentials Eliminate isolated cool spots in the paved mat that may be inadequately compacted and lead to early failure.
121 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Pavement Asphalt: tack coat application Methods to ensure the proper amount of tack coat is applied on existing surfaces (and on surfaces between pavement layers) to ensure proper bonding. Concrete: dowel alignment Measure and specify dowel bar alignment to reduce the risk of early pavement failure from misaligned dowels. Concrete: use HIPERPAV to predict early age concrete behavior Predict early age concrete pavement behavior to reduce the risk of early construction-related failure. Concrete: non- potable water for concrete mixtures and wash water Use non-potable water to reduce costs and conserve treated, potable water. Work zone traffic control Merge Control Methods to control vehicle merging behavior to improve mobility and driver/worker safety. Speed management Manage speed through work zones to improve driver and worker safety, and improve traffic mobility through the work zone. Driver information systems Systems designed to provide information to manage driver expectations and assist in detour route choice. Oversized load detection Technology to detect and warn oversized vehicles before they enter a work zone. Construction vehicle entering/exiting Technology to detect when trucks are entering/exiting the work zone and warn drivers. Materials Reduce materials use
122 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Materials Reuse existing materials in place Recycle highway materials Use co-products and waste materials from other industries Alternate or improved materials Local Materials Environmental Product Declarations (EPDs) EPDs are third-party verified cradle-to-gate life-cycle assessment based environmental impact declarations that reliably communicate potential environmental impacts from a material being used in construction. Safety Sustainable Construction Safety and Health Rating System (SCSH) Rates projects based on the importance given to worker safety and health. Job hazard analysis (JHA) Automated Flagger Assistance Devices (AFAD) Improves worker safety by replacing flaggers who are typically located near traffic approaching a work zone.
123 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Safety Work zone intrusion warning systems Technology used to notify workers and drivers of unauthorized vehicles entering work zones. Can reduces the risk of injury to exposed workers at a work zone site. Unmanned Aerial Vehicle Inspection Used to provide visual inspection of highway and bridge construction without the need to expose a worker to risks associated with operating at height, such as on a telescopic lift. Employment Meet disadvantaged business enterprise goals Have DBE/veteran-owned business goals. Local employment Training Sustainability training Additional training for safety or other items. Certification is a way to verify training done/passed. Utility issues, environmental issues, etc. Sustainability accreditation for individuals Get accredited in a green rating system. Community Project outreach In situations where a surrounding community is affected by a construction activity, contractor needs to directly communicate with and reach out to the community to ensure participation. Construction Noise Noise reduction based on ecological impact Mitigate construction noise near/within habitat sensitive areas to minimize ecological impact of noise. Backup alarm modifications and alternatives Boston CA/T project used adjustable noise alarms and spotters in place of traditional alarms for nighttime construction.
124 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Construction Noise Use computer models to predict construction noise Use the FHWAâs Roadway Construction Noise Model (RCNM), or equivalent, to predict construction noise. Construction Lighting Lighting plan Describes equipment and operations needed for a nighttime lighting system. Work zone glare reduction Reduce glare experience by drivers by using light types and mounting strategies. Semi-permanent high-mast lighting Use tall (on the order of 100 ft.) lighting to reduce glare and setup time for longer duration construction (4 months or longer). Design for Constructability Design for deconstruction Design that specifically accounts for and makes easier deconstruction at end-of-life. Adaptive reuse Reusing structures for a different purpose. Deconstruction Selective dismantling of infrastructure with the intention to reuse, repurpose, and recycle it. Constructability reviews for projects Formal design reviews to ensure they can be constructed using standard materials and methods, the plans/specifications are clear and non-conflicting, and the project can be reasonably be maintained over time. Quality Quality management plans Equipment Tier 4 engines In 2008-2015 EPA Tier 4 engines were phased in for non-road equipment. They reduce diesel NOx and particulate exhaust emissions by 90% from engines manufactured previous to the EPA rules. Alternative fuels Limited use of biofuel is already allowed and research continues on other alternative fuels. Automated grade control This is beneficial especially for projects with variable depth paving and milling.
125 Highway Construction Framework Sustainable Construction Practice Explanation (if needed)Level Category Project Equipment Vehicle Idling Policy Vehicle idling refers to running a vehicle's engine when the vehicle is not in motion. Vehicle idling reduction could reduce air pollution, carbon dioxide and toxic air emissions. Usually already required by law. Utilities Incorporating Utility Considerations in Highway Design The early consideration of utilities during highway design and maintenance scheduling can reduce the cost of relocation in later stages.
