Considering the ambitious greenhouse gas emission reduction and efficient use of resource targets set by the Sustainable Development Goals and the importance of concrete structures to achieve these goals, there is an increasing need to study the environmental performance of different concrete production alternatives. Cement is one of the main building materials that contribute significantly to global warming; therefore, studying the environmental performance of innovative binders that can substitute the use of cement is highly recommended. This article investigates the climate, material, energy, and water footprints of four innovative mixtures of ultra-high-performance concrete (UHPC) with a binder made of alkali-activated materials in comparison with the one made of Portland cement. Footprint analysis is carried out within cradle-to-grave life cycle assessment boundaries. Within the life cycle assessment, the functional unit defines the quantification of the final product or service. The functional units of the UHPC were adapted for the comparability of concrete mixtures with different compressive strengths. The results show that UHPC made with an alkali-activated material has 32%–45% better performance in terms of a climate footprint and 19%–33% better performance in terms of material footprints, whereas a trade-off can be seen regarding 44%–83% higher energy footprints and 75%–146% higher water footprints. The disadvantages in energy and water footprints are caused by waterglass. When allocation is considered, mixtures with high silica fume content have higher environmental footprints.

The construction industry contributes a major share to global warming and resource consumption. Steel-reinforced concrete (SC) is the world's most important building material, with over 100 million cubic meters used per year in Germany. In order to achieve a resource-efficient and climate-friendly construction sector, innovative technologies and the substitution of materials are required. Carbon concrete (CC) is a composite material made of concrete and a reinforcement of carbon fibers. Due to the non-rusting and high-strength carbon reinforcement, a much longer life-time can be expected than with today's designs. In addition, the tensile strength of carbon fibers is about six times higher than that of steel, so CC can be designed with a relatively lower concrete content, thus saving cement and aggregates. This research analyzes and compares SC with CC over its entire life-cycle with regard to its climate, material, energy, and water footprints. The assessment is done on material and building level. The results show that the production phase contributes majorly to the environmental impacts. The reinforcements made from rebar steel or carbon fibers make a significant contribution, in particular to the climate, energy, and water footprint. The material footprint is mainly determined by cement and aggregates production. The comparison on the building level, using a pedestrian bridge as an example, shows that the footprints of the CC bridge are lower compared to the SC bridge. The highest saving of 64% is in the material footprint. The water footprint is reduced by 46% and the energy and climate footprint by 26 to 27%. The production of carbon fibers makes a significant contribution of 37% to the climate footprint.

Buildings play an important role to meet Sustainable Development Goals, especially regarding the use of resources and greenhouse gas emissions. They are increasingly designed with energy-efficient solutions regarding their operations, while the related use of natural resources is still insufficiently considered. In this article, a methodology in Building Information Modeling is proposed to measure the resource and climate footprints of buildings’ heating systems. The methodology is applied to a case study building in Germany. The studied heating systems include a gas condensing boiler, ground-source heat pump, ground-source heat pump with a photo-voltaic system and air-source heat pump backed up with a gas boiler. Next to the operational energy, the production and transport of the heating systems were also studied. Results show that heating system operations have the largest impact and that the variant of ground-source heat pump combined with photovoltaics (GSHP + PV) has the lowest impact. In comparison with the gas boiler (GB), savings of 75%, 47%, 80%, and 84% are addressed to climate, material, energy, and land footprints, respectively, while the water footprint of GSHP + PV is 73% higher than that of GB.

Climate mitigation and efficient use of resources in the building sector have become a central issue for sustainable development. Promoting a circular economy and reducing global warming at the same time is an increasingly important challenge for construction, demolition and recycling of buildings. This study assesses the greenhouse gas emissions in relation to the resource use of recycled concrete (RC-concrete) and transfers the results into a Building Information Modelling application for visualization of the footprints results. The town hall building in the German city of Korbach was selected as a case study, which was selectively demolished and rebuilt with RC-concrete using recycled aggregates from the old building. The production of RC-concrete is compared with conventional concrete made from natural aggregates. The analysis covers the end of life and the production phase of concrete within the life cycle assessment (LCA) boundaries. The environmental assessment is done based on product climate, energy, material and water footprints, as reliable benchmarks for climate and resource efficiency in the building sector. RC-concrete can decrease the material footprint by up to 50%, whereas the reduction potential for the climate footprint is limited and the water footprint can be up to ten times higher with wet processing of concrete waste. The visualization of footprint results using LCA and digital planning software will further enhance the low carbon architectural design and circularity in the building sector.

Buildings are considered major drivers of resource use and climate change. This has initiated the development of design tools that could better reflect the environmental performance of buildings. This article describes the extension of building information modelling (BIM) through the development of the sustainable resource application (SURAP) that can be used to determine the material, water, and climate footprints of buildings at the design stage. The Python application programming interface (API) of openLCA software was used with the GaBi construction materials database for the preparation of footprint data. Footprints of construction materials were determined through life cycle assessments (LCA) on a cradle-to-gate basis, and the application was developed as a new tab in the Autodesk Revit software. The Revit API was used for data exchange between the Revit core system and the developed plug-in. The application prototype was tested for the design of a multifamily building. The results show that the developed tool can support building designers in quantifying and visualizing cradle-to-gate material, water, and the climate footprints of buildings within the BIM environment. The promotion of sustainability in the building industry and its current limitations are discussed.

There is a common understanding that the environmental impacts of construction materials should be significantly reduced. This article provides a comprehensive environmental assessment within Life Cycle Assessment (LCA) boundaries for Ultra-High-Performance Concrete (UHPC) in comparison with Conventional Concrete (CC), in terms of carbon, material, and water footprint. Environmental impacts are determined for the cradle-to-grave life cycle of the UHPC, considering precast and ready-mix concrete. The LCA shows that UHPC has higher environmental impacts per m3. When the functionality of UHPC is considered, at case study level, two design options of a bridge are tested, which use either totally CC (CC design) or CC enhanced with UHPC (UHPC design). The results show that the UHPC design could provide a reduction of 14%, 27%, and 43% of carbon, material, and water footprint, respectively.

Suitable methods and indicators to address the sustainability of resource use in the buildings sector are still in their infancy. Indicators and sustainability assessment schemes so far focus on the availability of natural resources, while the efficiency of their use is widely neglected. This article focuses on the assessment of the material resource use in buildings (abiotic raw material including energetic material), and the applicability of material input indicators, Raw Material Input (RMI) and Total Material Requirement (TMR), within life cycle assessment (LCA) using a contemporary database. The indicators cover the life-cycle-wide cumulative input of raw materials (RMI) and the total primary materials requirements (TMR) which in relation to the functionality of buildings ought to be minimized when resource efficiency shall be increased. The applicability of the resource use indicators in addition to the corresponding Global Warming Impact (GWI) is tested for a virtual design of a multi-family building. Use of resources and greenhouse gas (GHG) emissions are determined per square meter of usable floor area. The calculations comprised the production phase of the construction materials and the use phase of the building with five alternatives of exterior walls using GaBi XIV construction materials database. Results show that accounting for material input indicators i.e. RMI and TMR could significantly contribute to the reduction of a building's material resource use and explicitly define the actual input weight of each material resource taken from nature and the accompanied ecological rucksack within LCA framework.