No abstract

Local roads, which comprise 91% of the road networks in Indonesia, are a vital part of the transportation infrastructure. The construction of local roads has had some negative impacts on the environment, one of the most significant of which is the release of greenhouse gases (GHG). In order to develop a strategy for sustainable development in transportation infrastructure, it is essential that GHG emissions be reduced in the local road construction cycle. The aims of this study were to estimate the release of GHG and to elaborate on efforts to reduce GHG emissions in the construction of both rigid and flexible local road pavements. First, a life cycle assessment was performed to calculate the energy consumption and amount of GHG emissions. Next, some possible approaches were explored and elaborated on to seek opportunities to reduce GHG emissions, and therefore, enhance the sustainability of local road constructions. The results showed that material processing and material transportation contributed to 74.0-75.2% and 24.7-26.5% of GHG emissions, respectively. It is also known from the stepwise analysis that the significant predictor to form the amount of GHG both on the rigid and flexible pavement is the distance of the aggregate source to batching/asphalt mixing plant. Hence, the strategies for the reduction of GHG emissions, in this case, might be carried out by substituting current construction materials (cement and asphalt) with less intensive GHG emissions materials, and by reducing the distance for the transportation of the aggregates. The result shows that the first proposed strategy, which is substituting cement or asphalt with fly ash and reclaimed asphalt reduces more GHG than the second one.

Pusat Kesenian Jakarta Taman Ismail Marzuki (PKJ TIM) merupakan salah satu area yang sedang dilakukan revitalisasi oleh pemerintah. Revitalisai PKJ TIM Tahap II meliputi perencanaan, pembangunan, pengelolaan, dan perawatan. Pada pembangunan salah satu gedung yang terdapat di PKJ TIM Tahap II, Galeri Annex, memakan biaya sebesar 15,18% dari total keseluruhan biaya proyek Galeri Annex. Latar belakang dilakukannya penelitian ini karena galeri dinilai memiliki dimensi struktur yang cukup besar, sehingga kurang efisien. Pada penelitian ini dilakukan analisis menggunakan metode Value Engineering (VE) dengan tujuan untuk mengidentifikasi pekerjaan struktur yang dapat dilakukan efisiensi dan menghitung perbandingan biaya yang dihasilkan sebelum dan sesudah dilakukan analisis. Penelitan dilakukan dengan mengambil dua sampel, yaitu satu pekerjaan balok dan satu pekerjaan kolom. Pada sampel yang telah diambil, dilakukan perhitungan ulang dengan memunculkan alternatif pengembangan, yaitu menambahkan bahan pengganti semen (zat aditif) dalam campuran beton. Alternatif bahan aditif yang digunakan dalam penelitian ini adalah zeolit, silica fume, dan metakaolin dengan mutu beton secara berurutan, 34 MPa; 41,4 MPa; dan 45 MPa. Alternatif dibandingkan dengan struktur awal, yaitu beton f’c 30 MPa dengan campuran fly ash. Dari analisis yang telah dilakukan, alternatif yang terpilih adalah penggunaan beton f’c 45 MPa dengan campuran bahan aditif metakaolin. Berdasarkan perhitungan dengan metode VE, maka penggunakan alternatif metakaolin dapat menghemat biaya sebesar 25,20%.

Abstract. With massive explosion of population, the urban inhabitants will rise up to 64% in 2050. This condition increases the pressure on the existing urban road infrastructure and requires substantial maintenance and often expansion of the inter/rural-urban as well as local road as mobility of people and goods upsurge extensively. The construction of these new network and maintenance of existing road infrastructures consumes huge natural resources which further might increase volume of waste and greenhouse gas emission. Currently, approximately 28% provincial road and 41% local (urban) road network in Indonesia are in unsatisfactory condition. There is obvious demand to improve regional road with minimum ecological impact despite limited amount of resources and budget. In achieving sustainable road network, local authorities require a strategy in tackling this complex, large-scale and interconnected problems. This study aims to formulate relevant strategy for local authorities -urban or inter rural-urban level within a province -in operation, maintenance and development of road network by applying strategic management principles. Rational decision model was used in strategy formulation in three consecutive steps: input stage, Matching stage, and Decision Stage. Rational decision model was also used in strategy establishment taking into account the Environmental Minister regulation and some important issues in the Department of public works employing sustainability concept. The strategy proposed is believed to be ecologically sound (environmentally friendly) while improving local road network quality.