Characterization and mechanical removal of metallic aluminum (Al) embedded in weathered municipal solid waste incineration (MSWI) bottom ash for application as supplementary cementitious material

Municipal solid waste incineration (MSWI) bottom ash, due to its high mineral content, presents great potential as supplementary cementitious material (SCM). Weathering, also known as aging, is a treatment process commonly employed in waste management to minimize the risk of heavy metal leaching from MSWI bottom ash. Using weathered MSWI...

Non-destructive screening methodology based on handheld XRF for the classification of concrete: cement type-driven separation

The utilization of locally available concrete waste for producing recycled concrete aggregates is recognized as one of the most sustainable ways of satisfying the growing demand for concrete production. However, the quality of concrete waste depends on its origin and it may significantly differ from one concrete structure to another. Knowing the...

Plutonic Rocks as Protection Layers to Concrete Exposed to Ultra-High Temperature

Concrete structures perform poorly when withstanding thermal shock events, usually requiring repair or replacement after one single instance. In certain industries (such as petrol, metallurgic and ceramics), these events are not only likely but frequent, which represents a considerable financial burden. One option to solve this issue would be to...

Nano-modification in digital manufacturing of cementitious composites

Remarkable attention from both academia and industry has been attracted to extrusion-based 3D concrete printing (3DCP) during the last decade. Many companies in the Netherlands, e.g., Royal BAM Group, CyBe, Twente Additive Manufacturing, and Bruil, are attempting to implement this technology in practice. 3DCP is the focused digital concrete...

Surface effects of molten slag spills on calcium aluminate cement paste

Industries such as metal, ceramics and petrochemicals suffer from high temperature spills. Such events exert a unique form of loading in concrete structures that cannot be accurately simulated by heating of samples in an oven. Calcium aluminate cement (CAC) based concrete is the industry standard for such environment, and while much is known...

Characterization of air-void systems in 3D printed cementitious materials using optical image scanning and X-ray computed tomography

For many 3D printed cementitious materials, air voids may play a dominant role in the interlayer bond strength. However, to date, far too little attention has been paid to reveal the air void characteristics in 3D printed cementitious materials. Therefore, to fill this gap, this study attempts to provide an example of systematically...

Determination of loss of reinforcement due to corrosion through X-ray computer micro-tomography

X-ray computer scanning tomography (CT scan) is an increasingly more available technique, which has been applied to material sciences for years. Although most of its use is qualitative for gaining insights on material behavior, quantitative analysis for estimations of deterioration rates is possible. This paper describes an unbiased,...

Thermal, optical and mechanical properties of new glass compositions containing fly ash

The investigation of new compositions is crucial for the expansion of possible applications of glass, from the typical applications for building engineering, in the form of cast blocks or float glass, to more advanced technologies, such as 3D-printed glass or glass-to-metal connections. Since high melting temperatures and brittleness are two...

X-Ray Micro Tomography of Water Absorption by Superabsorbent Polymers in Mortar

Superabsorbent Polymers (SAP) have been recently subject of investigation as smart admixtures for cement-based materials. The properties of these polymers enable their use for internal curing, increasing freeze/thaw resistance, boosting autogenous self-healing and providing a crack self-sealing effect in cementitious composites. Except for...

Fundamental investigation on the frost resistance of mortar with microencapsulated phase change materials

Recent studies have shown that concrete containing Phase Change Materials (PCM) with low transition temperatures may reduce the number of freeze/thaw cycles suffered by the cementitious composite in temperate climates. Nevertheless, the positive influence of such admixtures on the frost resistance of cement-based materials has not been...

Chemo-physico-mechanical properties of the interface zone between bacterial PLA self-healing capsules and cement paste

In this study, the interface between different types of bacteria-embedded self-healing polylactic acid capsules (PLA) and cement paste is investigated. Particularly, the changes in microstructure and mechanical properties of the interface with respect to bulk cement paste were studied. First, nanoindentation was performed to obtain maps of...

Re-curing of calcium aluminate cements post contact with molten slag

Calcium aluminate cements (CAC) are widely used for the production of refractory concretes that are able to withstand extreme temperatures. During exposure to such temperatures, the main hydration phases revert to mayenite, calcium aluminate and calcium dialuminate. Many investigations focused on the description of this mechanism and how it...

Frost Damage Progression Studied Through X-Ray tomography In Mortar With Phase Change Materials

The potential of using phase change materials (PCM) in cementitious materials to mitigate damage due to thermal loadings has been recently focus of intensive research. In the case of PCM with transition temperatures near to the freezing point of water, their potential to delay frost in a cementitious matrix has been largely investigated through...

Dealing with uncertainty in material characterization of concrete by education

In this article a trip is taken to characterize concrete through its hardened cement paste based on its microstructure. Optical microscopy is coupled to advanced image analysis, as well as statistical data analysis to characterize heterogeneous concrete material. The article takes a closer look at the determination of the w/c ratio through the...

Development of ductile cementitious composites incorporating microencapsulated phase change materials

Abstract In the past two decades, much research has been devoted to overcoming the inherent brittleness of cementitious materials. To that end, several solutions have been proposed, mainly utilizing fibres. One of the most promising classes of materials is strain hardening cementitious composite (SHCC). It utilizes PVA fibres, and it is...