Circular concrete structures
Focus on concrete as a durable building material for circular concrete structures, incorporated into two research domains of the mission of research of University of Antwerp, i.e. Ecology & Sustainable Development and Materials Characterization. The research mission is integrated in the vision of circular economy and circular concrete, with reduced environmental impact (LCA) and financial analysis (LCCA) in the decision making process in the built environment. Bridging the gap between fundamental research, academic insights, practical implementation and expertise for the industry is the main goal of his research. Close cooperation with the industry is of high importance.
Regarding concrete technology and concrete structures we are facing challenges on the short and the long term. For the development of new structures the current design codes are mainly based on a deemed-to-satisfy approach that lacks a (semi-)probabilistic approach without taking into account durability related properties. Furthermore, the cement and concrete industry is responsible for approximately 5% of the CO2 emission. By replacing cement by supplementary binders (fly ashes, blast furnace slags, geo-polymers, etc.) or using waste streams (recycled building and other materials) in an adequate way the aim is to create durable/sustainable concrete structures with extended service life, reduced environmental impact and the capability to withstand the expected exposure conditions without interfering with the desired strength and stiffness. In depth characterization, determination and visualisation of thermal, hydral, mechanical and durability-related properties and implementing these obtained experimental data into probabilistic models is essential in order to produce reliable and eco-friendly building materials.
Regarding existing concrete structures other research opportunities are identified. Half of the existing concrete structures originate from the 70’s. As the mean life expectation of a concrete structure is 50 years, an almost inimitable demand of concrete repair projects can be expected. Therefore, it is our goal to be armed with validated protocols and a solid and a durable vision to come to a substantiated solution for durable repair and service life extension is needed. Current inspection regulations lack of clear guidelines regarding methodology, experimental/technical in-situ and lab program, rating strategy during diagnosis, etc. The repair of concrete structures should be integrated in the entire life cycle of the building and the decision making strategy in the end-of-life phase should be based on both environmental and financial criteria.
Therefore, the mission within EMIB research group of the University of Antwerp, is integrated in all aspects of the life cycle of concrete buildings and civil structures:
durable design and development of new and sustainable concrete and low-impact cementitious materials for infrastructure (bridges, tunnels, etc.) and the built environment (residential buildings, etc.) with optimal use of cementitious materials in high-performance elements including property characterization via experimental testing using destructive and non-destructive techniques.
use of alternative binders and low-impact alternatives for clinker cement (e.g. fly ashes, geopolymers, etc.) without negatively interfering the microstructure, the strength characteristics and transport mechanisms.
diagnosis and condition assessment of existing concrete structures with focus on remaining service life estimation and bearing capacity determination by means of a (semi-)probabilistic approach, interpretation and modification of existing inspection protocols and regulations including development of novel approaches and strategies for assessing the remaining service life and bearing capacity of existing concrete structures.
use of non-destructive techniques (IR-thermography, permeability tester, UPV, radar, ultrasonic tomography, etc.) for material characterization of new durable and reconstruction and investigation of existing structures.
environmental and financial evaluation of design, maintenance and repair strategies and service life extension of reinforced concrete structures by means of electrochemical treatment (e.g. cathodic protection).
end-of-life decision making based on environmental and financial criteria via LCA/LCCA and end-of life estimation and recycling with integration of waste materials (recycled polymers, rubber, etc.) as resources for newly developed circular concrete structures.