Energy consumption of bridge construction: conventional vs precast girders

One of the ways to reduce the negative impact of construction projects on the environment is reducing energy consumption. This study aims to calculate the energy consumption of a bridge construction project on the conventional beam girder and the precast girder. Data collection was carried out on the Salatiga-Surakarta toll road bridge project package 4.1 through field observations and interviews with project stakeholders. The results showed that the estimate of conventional girder energy consumption during the raw material transporting stage is 2.857 MJ/km.m3 (4.87%), during the production is 19.989 MJ/km.m3 (34.11%), during the transporting to the location is 3.56 MJ/km.m3(6.07%), and lastly, during the construction stage is 32.201 MJ/km.m3 (54.94%). While the estimate of energy consumption of precast girder at the raw material transporting stage is 2,897 MJ/km.m3 (5.27%), during the production is 49.627 MJ/km.m3 (90.29%), the transporting to the location is 0.957 MJ/km.m3 (1.74%), and during the construction stage is 1.485 MJ/km.m3 (2.70%). The total energy consumption of conventional girders is 58.606 MJ/km.m3 (51.60%), while for precast girder is 54.965 MJ/km.m3 (48.40%). The conventional girder energy consumption is 3.20% greater than the precast girder, thus, in this case, the precast girder is the best alternative to reduce the energy consumption during bridge construction activities. This study provides an understanding of environmental impacts based on the amount of energy consumption of conventional and precast girders, which is useful in the selection of girder beam types that are more environmentally friendly.