In 2020, the production of cement in Germany generated over 20 mill. t CO₂ equivalent emissions [1], constituting approximately 3% of the national CO₂ output [2]. Worldwide, the industry was responsible for 7% of all global emissions [3, 4]. Cement being one of the core components of the indispensable construction material concrete only further highlights the dire necessity for improving its environmental impact and sustainability. However, effectively reducing emissions in both industries requires more in-depth scrutiny than mere one-dimensional analyses.

Aided by previous research findings, this project strives to provide a holistic description of sustainability in the concrete production industry. The goal lies in optimizing the cycle to ensure as many of the required components are replaced by secondary raw materials as possible. This initial step in developing comprehensive concrete recycling will be undertaken in cooperation with the Institutes for Technical Chemistry (ITC) and Concrete Structures and Building Materials (IMB). The planned feasibility study will shed light on the current state of both cement and concrete industries, describe system requirements and potentials, and aim at providing a recommended course of action.

The approach goes beyond viewing an industry’s sustainability merely in terms of its climate neutrality. Aside from ecological aspects, durability, economic efficiency, recyclability, and social acceptance are considered crucial factors. This study will take stock of recycled concrete and available secondary raw materials, identify system potentials, and discuss the feasibility of a holistic recycling approach. Concrete will be regarded as more than just construction material within a production process. All aspects of its lifecycle will fall under scrutiny: the recycling of useable secondary raw materials, concrete production itself, transportation, processing, and usage. In particular, the various kinds of therein involved processes will financially be evaluated and compared. This will allow a meaningful overview of methodological advantages and their sustainability to be deduced, which in turn can form the basis of a multi-criterial evaluation and help specify decision-supporting guidelines.

[1] VDZ – Zahlen und Daten (Numbers and Data) https://www.vdz-online.de/zementindustrie/zahlen-und-daten/umweltdaten (last viewed 27.4.2022)

[2] Umweltbundesamt – Treibhausgasemissionen in Deutschland (Greenhouse gas emissions in Germany)  https://www.umweltbundesamt.de/daten/klima/treibhausgas-emissionen-in-deutschland#emissionsentwicklung (last viewed 27.4.2022)

[3] IEA – Cement https://www.iea.org/reports/cement (last viewed 27.4.2022)

[4] Destatis – Treibhausgase: G20 verursachen rund 80% der globalen CO2-Emissionen (Greenhouse gases: G20 cause around 80% of global CO2 emissions) https://www.destatis.de/DE/Themen/Laender-Regionen/Internationales/Thema/umwelt-energie/umwelt/G20_CO2.html (last viewed 27.4.2022)