鉄道インフラ建設におけるCO₂eq排出量のライフサイクル評価

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:鉄道建設LCAの研究動向とホットスポット、削減戦略のエビデンスマップを把握できる。

🏢実務担当者:建設段階のCO₂eq削減策（低炭素結合材・プレキャスト・掘削材再利用）を計画初期に組み込む判断材料になる。

🏛政策担当者:鉄道インフラ入札にLCA基準と地域別排出係数を導入する根拠を提供する。

Introduction. Rail is promoted as a low-carbon transport mode, yet building its fixed infrastructure mobiliseslarge volumes of cement, steel, earthworks and energy, creating an embodied-carbon burden that materialises before operations begin. Life cycle assessment (LCA) is the consolidated methodology for quantifying this burden, but its application to Brazilian railway planning remains incipient. Objectives. To identify, classify and critically appraise how LCA methodologies have been applied to quantify and reduce carbon-dioxide-equivalent (CO₂eq) emissions from railway infrastructure construction, and to discuss the conditions for transferring these methodologies to the consolidation of Brazilian railway-infrastructure planning. Methods. A systematic review reported with reference to the PRISMA 2020 statement. Scopus and Web of Science (All Databases, All Collections) were searched on 21 April 2026 using the same Boolean query. Screening, full-text assessment and extraction were conducted by one reviewer. Eligible studies were classified as primary mitigation studies or diagnostic studies. Owing to methodological heterogeneity, evidence was combined through a structured narrative synthesis and an evidence map organised into eight strategy families, retaining each result's original boundary, functional unit and baseline. Results. Of 365 retrieved records, 254 were screened, 37 assessed at full text and 34 entered the substantive synthesis (21 primary mitigation studies and 13 diagnostic studies). Cement, concrete and reinforcing steel, tunnels and underground stations, earthworks and site energy were the recurring hotspots. Nineteen primary studies reported at least one quantified reduction, with illustrative values ranging from about 29% for alkali-activated slag sleeper concrete and 48–51% for lower-carbon precast platform components to 12.59% for a prefabricated subway station. No study reached high confidence, and the Brazilian evidence identified was exclusively diagnostic. Conclusions. The evidence supports embedding LCA early in the railway project decision cycle, with a construction-carbon baseline set during planning, material efficiency before input substitution, lower-carbon binders and steel, reuse of excavated and demolition material, optimised track forms and structures, and cleaner site energy. Foreign percentages should not be transposed directly to Brazil: the renewable profile of the electricity mix, the clinker factor of national cement, and project-specific supply distances and transport modes may alter both the magnitude and the ranking of measures, making regional emission factors and full-scale Brazilian case studies a priority.

• semanticscholar https://doi.org/10.35265/2236-6717-274-13343first seen 2026-09-19 05:43:36 · last seen 2026-09-22 05:12:22