Challenges and Performance of Filter Dusts as a Supplementary Cementitious Material.

Global industry relies on a linear approach for economic growth. One step towards transformation is the implementation of a circular economy and the reclamation of anthropogenic deposits. This study examines two filter dusts, one German and one Argentinian, from the production of calcined clays, representing such deposits.

Optimized Building Envelope: Lightweight Concrete with Integrated Steel Framework.

This study presents a novel construction method for prefabricated wall elements by integrating a framework made of thin-walled sheet steel profiles into an optimized thermally insulating lightweight aggregate concrete (LAC) building envelope. The load-bearing function of the framework is provided by cold-formed Sigma-profiles, which are spot-welded to non-load-bearing U-profiles at the vertical ends. The LAC shapes the wall and stabilizes the thin-walled steel profiles against buckling, but has no further load-bearing function, thus allowing the reduction of its necessary compressive strength and subsequently minimizing its density.

Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications.

Systematic investigation of filtrates and filter residues resulting from a 24 h treatment of metakaolin in different alkaline solutions were performed. On filtered metakaolin particles, inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements reveal an enrichment of iron and titanium, which suggests an inhomogeneous distribution of these cations. Since the SiO/AlO ratio remains constant in all filter residues examined, the dissolution of the Si and Al monomers is congruent.

Lightweight Concrete-From Basics to Innovations.

Lightweight concrete has a history of more than two-thousand years and its technical development is still proceeding. This review starts with a retrospective that gives an idea of the wide range of applications covered by lightweight concrete during the last century. Although lightweight concrete is well known and has proven its technical potential in a wide range of applications over the past decades, there are still hesitations and uncertainties in practice.