Florian Kleiner

Bauhaus-Universität Weimar ·  F. A. Finger-Institut für Baustoffkunde

Salt hydrates of MgSO4, ZnSO4 and SrCl2 are promising materials for thermochemical heat storage applications. It is necessary to know the thermal conductivity of their hydrates in order to optimize heat storage systems. Therefore, the hydrates which occur as reaction products of a hydration were pressed into pellets and the thermal diffusivity was...

Chemical glass frosting processes are widely used to create visual attractive glass surfaces. A commonly used frosting bath mainly contains ammonium bifluoride (NH₄HF₂) mixed with hydrochloric acid (HCl). The frosting process consists of several baths. Firstly, the preliminary bath to clean the object. Secondly, the frosting bath which etches the r...

Scanning electron microscopy (SEM) imaging is able to visualize micro- to nano-structures of cement and concrete. A prerequisite is that the sample preparation preserves the native structure of the specimen. In this study, argon broad ion beam (BIB) sectioning is compared to state-of-the-art sample preparation (resin embedding, polishing) for hydra...

This study demonstrates the application and combination of multiple imaging techniques (Light Microscopy, Micro X-ray Computer Tomography (μ-CT), Scanning Electron Microscopy (SEM) and Focussed Ion Beam - Nano Tomography (FIB-nT)) to the analysis of the microstructure of hydrated alite across multiple scales. However, by comparing findings with mer...

This study combines 2D element mappings obtained by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS) and energy dispersive X-ray spectrometry (EDX) in the scanning electron microscope (SEM) to analyse the chemical composition of cement clinker phases. It is revealed that this approach enables to determine the major and t...

The substitution of Portland cement clinker with a combination of limestone, calcined clays and set regulator (calcium sulphates) is a promising way to reduce CO2 emissions of concrete. These cements are described as Limestone Calcined Clay Cement (LC3, https://lc3.ch/). Calcined clays are known to have a high specific surface area, which results i...

The demands on modern building materials are constantly increasing. Innovativesolutions produce a multitude of binders and concretes that often have a verycomplex, multiscale heterogeneous composition. Multi-scale imaging of structuralcharacteristics is still a challenge but will provide basic understanding of essentialmaterial properties.Over cent...

To accurately simulate the hydration process of cementitious materials, understanding the growth rate of C-S-H layers around clinker grains is crucial. Nonetheless, the thickness of the hydrate layer shows substantial variation around individual grains, depending on their surrounding. Consequently, it is not feasible to measure hydrate layers manua...

Coupling of microstructural and physico-chemical modelling of cement hydration is a key step towards prediction of material performance. In this paper, a physicochemical model based on surface reactions and ion transports is proposed to capture the development of calcium-silicate-hydrate (C-S-H) not only at an early age but also at later ages of hy...

This study combines 2D element mappings obtained by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS) and energy dispersive X-ray spectrometry (EDX) in the scanning electron microscope (SEM) to analyse the chemical composition of cement clinker phases. It is revealed that this approach enables to determine the major and t...

This study demonstrates the application and combination of multiple imaging techniques [light microscopy, micro-X-ray computer tomography (μ-CT), scanning electron microscopy (SEM) and focussed ion beam – nano-tomography (FIB-nT)] to the analysis of the microstructure of hydrated alite across multiple scales. However, by comparing findings with mer...

Burning of clinker is the most influencing step of cement quality during the production process. Appropriate characterization for quality control and decision making is therefore the critical point to maintain a stable production but also for the development of alternative cements. Scanning electron microscopy (SEM) in combination with energy dispe...

Scanning electron microscopy (SEM) imaging is able to visualize micro- to nano-structures of cement and concrete. A prerequisite is that the sample preparation preserves the native structure of the specimen. In this study, argon Broad Ion Beam (BIB) sectioning is compared to state-of-the-art sample preparation (resin embedding, polishing) for hydra...

This dataset visualizes the electron beam damage induced by a scanning electron microscope (SEM) in calcium silicate hydrates (C-S-H). The specimen used is 28 days hydrated alite (water/solid = 0.5). It was scanned using a thermofischer scientific Helios G4 UX microscope at 350 V/25 pA with a stage bias of 200 V. This animation was an afterthought...

Demonstration of the application of FIB/SEM on hydrated alite

This is the recording of the presentation "Utilizing Modern FIB/SEM Technology and EDS for 3D Imaging of Hydrated Alite and its Pore Space"

The exploration of cementitious materials using scanning electron microscopes (SEM) is mainly done using fractured or polished surfaces. This leads to high-resolution 2D-images that can be combined using EDX and EBSD to unveil details of the microstructure and composition of materials. Nevertheless, this does not provide a quantitative insight into...

A new method for the nuclear magnetic resonance (NMR) surface relaxivity calibration in hydrated cement samples is proposed. This method relies on a combined analysis of 28-d hydrated tricalcium silicate samples by scanning electron microscopy (SEM) image analysis and 1 H-time-domain (TD)-NMR relaxometry. Pore surface and volume data for interhydra...

Sichtbeton ist aufgrund seiner Vielfältigkeit in der Formgebung eines der am meisten verbreiteten Gestaltungsmittel der modernen Architektur und optimal für neue Bauweisen sowie steigende Anforderungen an das Erscheinungsbild öffentlicher Bauwerke geeignet. Die Herstellung qualitativ hochwertiger Sichtbetonoberflächen hängt im hohen Maße von den We...

In the presented paper, the results of a BMWi-supported project of applied research are reported. The main objective of this work is the development of a system of PC elements for the application as roof or floor plates. Based on the determination of the creep behaviour of the PC at different temperatures, reinforcement techniques for the PC elemen...

Zur Erstellung von dekorativen, filigranen Plastiken wurden Mörtel entwickelt, die eine hohe Biegezugfestigkeit und eine geringe Schwindneigung aufweisen sollten. Weiterhin standen die mineralische Anmutung des erhärteten Materials sowie eine in weiten Bereichen einstellbare Konsistenz des Frischmörtels für verschiedene Herstellungsarten, wie Gieße...

Mit dem stetigen Steigen des Anteils an erneuerbaren Energien wird der Einsatz von Speichern immer bedeutsamer. Neben der Speicherung elektrischer Energie ist die Speicherung anfallender solarer bzw. industrieller Wärme eine wichtige Herausforderung. Aufgrund der hohen Energiespeicherdichte kommt dabei der thermochemischen Wärmespeicherung eine ent...