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37 TABLE 38 WRITTEN RESPONSES FOR ENVIRONMENTAL BENEFITS Environmental Benefits: Can you quantify these environmental benefits? If so, please provide a summary of these quantified benefits. State Responses Contractor Responses FDR reduces pavement structure requirement 20%50% By virtue of the CIR process, the city estimates that over 840 truck trips were eliminated from CIP sometimes reduces overlay thickness required up to traveling over city streets during the construction operation. In addition, the process saved 50%. (IA) 1,649 barrels of oil, while reducing the overall carbon emissions by approximately 80% com- Less use of virgin materials and use of resources. (MD) pared with the alternative methods of rehabilitation the city considered. It reduced the entire project time by 5 working days and at the same time saved over $262,000 for the city No--varies by project. (WY) No Experience to quantify (DE) CIR Foamed Asphalt Project I-80, Caltrans data show the CIR process saved 101,909 metric tons aggregate, 2,545 metric tons bitumen, 9,200 truck trips @ 80 km round trip, 736,000 No. Information is not available. (ID) truck traveled km, 204,000 liters of diesel, and 7200 kg of 0x emissions. Not enough projects to quantify benefits. (AZ) On a 5.5 mile segment constructed in two sections, the existing HMA pavement 22 ft wide The emission savings are quantified using PaLATE soft- was widened to a 28-ft wide bituminous base course using an FDR process. The material ware. The emissions savings for using CIR or CIREAM from the widening trench was stockpiled to be used as shoulder material after the paving was are: 52% reduction in carbon dioxide; 54% reduction in completed. The widening material came from milling the existing surface, placing the mill- nitrogen oxide; 61% reduction in sulfur dioxide com- ings in the widening trench and processing the entire width--eliminating the longitudinal pared to traditional HMA paving operation. (MTO) widening joint. This project saved 2,800 tons of aggregate that would have been used as There also is a reduction in the hauling of material to the shoulder material. This process also eliminated the need of providing 9,040 tons of a HMA site. Actual quantities are hard to estimate as full imple- widening material. mentation has not been done. (UT) Documented a 50% savings in CO2 emissions, 55% savings in 0x emissions, and 60% sav- We have not documented any environmental benefits, ings in SO2. but it is assumed that these projects use less virgin mate- rial then a non-recycled project. (ND) Other contractor savings noted, but without quantities included reductions in: CO2 emissions Collateral ESALs on adjacent roadways Need for future maintenance (i.e., proven long-term solution) Construction traffic congestion (i.e., fewer trucks) Fuel consumption COST BENEFITS Heater repaving averaged $2.17 per square yard, but the database contained only two projects con- Cost savings reported in the literature include structed over the 8-year period. FDR costs vary with the selection of additives and sta- Canadian research, which showed that the net present bilizers (Mallick et al. 2002): value of the CIR option was 13% higher than an over- Pulverized material with water and mechanical sta- lay; however, the costbenefit ratio was 8 times greater bilization was $2.00 to $2.10 per square meter. (Cuelho et al. 2006). Emulsion stabilization was $3.50 per square meter. North Dakota research showed that selecting the most Emulsion with lime (2%) additive was $3.75 to appropriate surface treatment for traffic conditions can $3.85 per square meter. result in significant savings. One project evaluation Emulsion with cement (5%) was $3.25 to 3.35 per showed that CIRdouble chip overlay was $180,000/ square meter. mile for higher traffic sections, but changing to a CIR FDR saved 25% of the project cost compared with stan- single chip seal for lower traffic sections reduced the dard reconstruction (Rosenmerkel 2003). cost to $80,000/mile (costs also were lower because Maine reported a cost savings by using FDR of $8.86 traffic control was provided by the county). per square meter when compared with full conventional HIR costs vary with the type of HIR used for the proj- reconstruction, which included excavation, placement, ect. The Colorado DOT experience with HIR recycling grading, compaction, and paving (Harrington 2005). from 2000 to 2008 showed the following differences in Nevada projects showed that cost (Fisher 2008): Savings of $104,000 per centerlane-mile savings Heater scarifier treatment averaged $1.55 per square could be realized if a 75-mm (3-in.) CIR with dou- yard for 19 projects, with quantities recycled from ble chip seal wearing course was used instead of the 50,000 to more than 350,000 square yards of old conventional HMA. pavement surface. Savings of $38,000 to $93,000 per centerline mile Heater remixing averaged $3.74 per square yard could be realized with FDR, CIR, and CIR with for 37 projects 50,000 to more than 500,000 square stockpiled millings compared with conventional yards in size. HMA approaches to address structural deficiencies.