Official Journal of the Japan Wood Research Society
Table 4 Sensitivity analysis for service life of wooden beams for each type of wooden guardrail over a 40-year evaluation period
From: Life cycle greenhouse gas emission of wooden guardrails: a study in Nagano Prefecture
Wooden type no. 1 | Wooden type no. 3 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Painting treatment | Pressure injection | Painting treatment | Pressure injection | |||||||||
Actual condition | −5 year | +5 year | Actual condition | −5 year | +5 year | Actual condition | −5 year | +5 year | Actual condition | −5 year | +5 year | |
Raw material procurement and production process | ||||||||||||
Resource extraction—support post production | 12.80 | 12.80 | 12.80 | 12.80 | 12.80 | 12.80 | 14.00 | 14.00 | 14.00 | 14.00 | 14.00 | 14.00 |
Resource extraction—steel beam production | 33.08 | 33.08 | 33.08 | 33.08 | 33.08 | 33.08 | – | – | – | – | – | – |
Resource extraction—connector production | 5.75 | 5.75 | 5.75 | 5.75 | 5.75 | 5.75 | 4.83 | 4.83 | 4.83 | 4.83 | 4.83 | 4.83 |
Silviculture—wooden beam production | 0.66 | 0.66 | 0.66 | 0.66 | 0.66 | 0.66 | 1.49 | 1.49 | 1.49 | 1.49 | 1.49 | 1.49 |
Preservative procurement—pressure injection | – | – | – | 4.35 | 4.35 | 4.35 | – | – | – | 4.07 | 4.07 | 4.07 |
Resource extraction—paint production | 0.37 | 0.37 | 0.37 | – | – | – | 0.47 | 0.47 | 0.47 | – | – | – |
Construction process | 0.59 | 0.59 | 0.59 | 0.59 | 0.59 | 0.59 | 2.82 | 2.82 | 2.82 | 2.82 | 2.82 | 2.82 |
Maintenance and management process | ||||||||||||
Replacement of wooden beams (the 5th year) | – | 1.03 | – | – | – | – | – | 1.96 | – | – | – | – |
Replacement of wooden beams (the 10th year) | 1.03 | 1.03 | – | – | – | – | 1.96 | 1.96 | – | – | – | – |
Replacement of wooden beams (the 15th year) | – | 1.03 | 1.03 | – | 5.01 | – | – | 1.96 | 1.96 | – | 5.56 | – |
Replacement of wooden beams (the 20th year) | 1.03 | 1.03 | – | 5.01 | – | – | 1.96 | 1.96 | – | 5.56 | – | – |
Replacement of wooden beams (the 25th year) | – | 1.03 | – | – | – | 5.01 | – | 1.96 | – | – | – | 5.56 |
Replacement of wooden beams (the 30th year) | 1.03 | 1.03 | 1.03 | – | 5.01 | – | 1.96 | 1.96 | 1.96 | – | 5.56 | – |
Replacement of wooden beams (the 35th year) | – | 1.03 | – | – | – | – | – | 1.96 | – | – | – | – |
Disposal process | ||||||||||||
Energy use of disposed wooden beams | −43.11 | −86.21 | −21.55 | −21.55 | −21.55 | −10.78 | −115.75 | −231.49 | −57.87 | −57.87 | −57.87 | −28.94 |
Material use of disposed steel and concrete | −21.29 | −21.29 | −21.29 | −21.29 | −21.29 | −21.29 | −13.27 | −13.27 | −13.27 | −13.27 | −13.27 | −13.27 |
Total | ||||||||||||
Greenhouse gas (GHG) emissions (raw material procurement and production—maintenance and management process) | 56.36 | 60.50 | 55.33 | 62.24 | 67.25 | 62.24 | 29.50 | 37.35 | 27.54 | 32.77 | 38.33 | 32.77 |
Net GHG emissions (raw material procurement and production—disposal process) | −8.03 | −47.00 | 12.48 | 19.40 | 24.41 | 30.17 | −99.52 | −207.42 | −43.61 | -38.38 | −32.82 | −9.44 |