Thesis and Project Arbeit Offers

Master’s Thesis (MSc) – Wet Carbonation of Recycled Concrete Aggregates: Quantifying CaCO₃ Formation via TGA, XRD and SEM

Master’s Thesis Offer (M.Sc.) – Materials Science / Chemical Engineering
Topic: Wet Carbonation of Recycled Concrete Aggregates (RCA): Quantifying CaCO₃ Formation Using TGA, XRD and SEM

Background
Recycled concrete aggregates (RCA) are a key lever for circular construction, but their high porosity and water absorption can limit performance in new concrete. Wet carbonation pre-treatments can densify the adhered mortar and promote CaCO₃ precipitation, potentially improving aggregate quality while storing CO₂. This thesis focuses on quantifying carbonation products and understanding microstructural changes induced by pre-treatment.

Objective
The goal is to evaluate the level of carbonation in pre-treated RCA and quantify how much CaCO₃ has formed using complementary characterization techniques:

  • TGA/DTG to quantify carbonate content and CO₂ uptake (with baseline subtraction for pre-carbonated RCA)

  • XRD (qXRD/Rietveld, optional internal standard) to identify/quantify calcite/vaterite/aragonite

  • SEM (with EDS if available) to investigate morphology, pore/ITZ densification, and carbonate precipitation

Main Tasks

  • Literature review on wet carbonation of RCA and quantitative methods for CaCO₃ determination

  • Experimental design for carbonation pre-treatment parameters (time, CO₂ supply, liquid chemistry)

  • Sample preparation and execution of TGA, XRD, and SEM measurements

  • Quantification of CaCO₃ formation (wt% and/or CaCO₃-equivalent) and comparison across pre-treatment conditions

  • Interpretation of results linking phase changes and microstructure to expected changes in aggregate quality (e.g., porosity/water absorption indicators)

If you are interested send an email to ariana.morales@tuhh.de