Materials for Civil Engineering group

Development of cements and construction materials which are more respectful of the environment

 The construction sector uses an important part of the world's mineral resources (shortage of sand, etc.) and requires major energy input (binder firing, etc.), which accounts for a significant share of CO2 emission. Research in this field aims to reduce the environmental footprint of construction materials in three complementary ways:

• Recycling of industrial by-products and deconstruction waste (concrete recycling) such as aggregates, hydraulic binder constituents or cement raw materials, thus limiting the use of landfill sites and preserving natural resources.
• Development of sulphoaluminate cements (CSA): study of their composition, hydration and specific tests with a view to standardization. Their manufacture releases less CO2 than traditional Portland cements do.
• Study of alternative construction techniques (mud brick, banco or straw construction - binders).

Projects:

• National RECYBETON Project
• Interreg VB SeRaMCo Project
• MSCA-ETN SOCRATES

Thesis:

INERFOND Industrial Project Chahinez AISSAOUI 2020/2023

Article:

Greening effect of slag cement-based concrete: environmental and ecotoxicological impact, Environmental Toxicology and Chemistry, Couvidat J., Diliberto C., Meux E.,  Cotelle S., Bojic C., Izoret L., Lecomte (2021)

Durability of contemporary materials and structures

The durability of structures is a major issue in the construction sector to meet the requirements of sustainable development. Several approaches are addressed by group members:

• The biodeterioration of cement based materials evolving in real environments (the Moselle River, sewerage network). The approaches addressed are the analysis of the physicochemical evolutions of surfaces, the density of bacterial colonization, properties of hydrous transfers within the porous network of the material
   
• The operating life of a structure can often last as long as between 50 and 100 years. Therefore, some civil engineering structures require reinforcement or repairs to maintain their serviceability. Reinforcement and repair techniques for concrete structures, in particular using composite materials (carbon, flax fibres, etc.), are promising and rapidly developing
   
• New "portable" Raman spectroscopy techniques are used to monitor the degradation of structures in situ

Projects:

• Collaboration with the LMOPS and Université Gustave Eiffel - IFSTTAR for the preparation of a thesis on Raman spectrometry
• Collaboration with ICube, Civil and Energetic Engineering groups

Thesis:

Ministerial doctoral contract Nadjib BRAHIM, 2019-2022

Article:

Portable quantitative confocal Raman spectroscopy: non-destructive approach of the carbonation chemistry and kinetics, Cement Concrete Research, Marchetti M., Mechling J.-M., Diliberto C., Brahim M. N., Trauchessec R., Lecomte A., Pourson P., (2021)

Modelling of structures

Development

• Synthesis of pure cementitious phases (Ye'elimite, Alite, Belite, etc.)

Experimentation

• Manufacture of large-scale components (beams up to 10 metres in length, semi-large walls) then mechanical tests on appropriate benches (15m span bending bench equipped with two 250 kN jacks, 500 kN capacity column press, 2×3m bi-axial thrust bench equipped with 150 kN jacks, etc.) with monitoring of strengths and/or instabilities: deformation sensors arranged on the surface and in the parts according to the forces applied
   
• Durability tests under special climatic conditions (temperature-humidity control / freeze-thaw) or CO2-rich atmospheres.

Characterization

• Conventional laboratory testing of cement in a controlled atmosphere: Pycnometry (water or helium), ultra-fine grain size (Laser / Alpine sieve shaker), micro-calorimetry and Langavant calorimetry, air permeability of binders, measurement of endogenous or total shrinkage as soon as pouring, thermo-gravimetric and thermo-differential analysis (in collaboration with the Surfaces and Interfaces group: Chemical Reactivity of Materials), electron microscopy (CC 3M), X-ray diffraction and X-ray Fluorescence (CC X-Gamma) characterizations, etc
   
• Conventional concrete laboratory tests on fresh binding materials, including rheology measurements with a rheometer
   
• Mechanical tests on materials (compressive and tensile strengths / elastic modulus measurements) and on complex structures

Technological transfer

The Materials for Civil Engineering group collaborates regularly with industry (corporations, SMEs, standardization committees etc.), and the scientific and technological results obtained are used to improve processes, sometimes in the form of patents:

• Processing of steel mill slag in civil engineering (concrete, road aggregates)
• Study of the chemical behaviour of Portland and Sulphoaluminate cement mixtures
• Procedure for calculating structures sensitive to second-order effects adopted by the SFECE (French Building Federation)
• Development of a new wood-concrete connector (currently being finalized and transferred)

Professors, assistant professors

• Firas AL MAHMOUD
• Rémi BOISSIERE
• Cécile DILIBERTO
• Sarah JANVIER-BADOSA
• Abdelouahab KHELIL
• Jean-Michel MECHLING
• Charlotte MERCIER
• Sébastien ROUX
• Romain TRAUCHESSEC

PhD students

• Léonard AXUS
• Nadjib BRAHIM
• Agathe Rosane Charlotte Marie DUJARDIN
• Yahya EL BERDAI
• Abdoulaye KONATE
• Mathias LEJEUNE
• Quentin NESTELHUT

Post-doctoral researchers

• Mimoune ABADASSI
• Omar RODRIGUEZ VILLARREAL