same top 4 emissions and the same contributing processes to the emissions ranging from

4.95E+01 to 1.62E+03. Due to the higher transportation of machinery and the lower

amount of salvaged materials, the largest producer of carbon dioxide was the

transportation of equipment, followed closely by the transportation of labor and the use of

the generator. As with the 44% manual scenario the emissions were lower than the 100%

manual and the 100% mechanical scenario due to less material being landfilled and less

time being spent in transportation of labor and cleanup of the salvaged materials. Table

3-7 provides emissions resulting from 100% mechanical demolition of a barrack. The

highest total emissions in this scenario were greenhouse gases, carbon dioxide (CO2,

3.40E+02 g/ft2) and carbon monoxide (CO, 2.52E+02 g/ft2). Also high were emissions

of nitrogen oxides (NOx), volatile organic compounds (VOCs) and methane (CH4). The

greatest contributor of C02, CO, NOx and CH4 was the landfill used for disposal of waste

materials, whereas the main source of VOC's was the transportation of labor and

equipment to and from the site. Equipment operation was also a significant contributor to

CO2 emissions.

 A sensitivity analysis was performed on the results from the impact assessment to

determine the influence of variables on the environmental impacts considered. The

model produced in SimaPro was most sensitive to changes in the mileage driven by

workers onsite machine use and the operation time of the generator. It was shown that

environmental impacts decrease with higher levels of materials salvaged. However,

detrimental impacts were shown to rise with transportation distance to the new

construction site or to a storage facility. Impacts also increased with increasing

deconstruction time because of the increased number of days workers drove their cars to