Self-healing of cementitious materials using sustainable cenosphere-based manufactured aggregate

Self-healing concrete using encapsulated healing agent has shown great potential in enhancing concrete durability. However, the capsules are expensive to make and can lower the mechanical properties of concrete. In this study, a new type of manufactured aggregate that employs waste-derived fly ash cenosphere as a carrier of healing agent (SH...

Microstructural evolutions and impact toughness in simulated welding heat affected zones for a high-strength carbide-free bainitic rail steel

Systematic experimental investigations were conducted to study the microstructures and impact toughness of each heat affected zone (HAZ) formed during rail flash-butt welding. A high-strength carbide-free bainitic rail steel was subjected to different thermal simulation cycles to separately reproduce each HAZ subzone by tailoring the peak...

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging....

A novel capsule-based selfrecovery system with a chloride ion trigger

Steel is prone to corrosion induced by chloride ions, which is a serious threat to reinforced concrete structures, especially in marine environments. In this work, we report a novel capsule-based selfrecovery system that utilizes chloride ions as a trigger. These capsules, which are functionalized via a smart response to chloride ions, are...

The effect of processing parameters on the formation of epoxy/UF resin microcapsules

Epoxy E-51/UF resin microcapsules were prepared by traditional two-stepped in situ polymerization method and processing parameters affecting the final microcapsules’ shape and size were carefully studied in the aim to obtain microcapsule with ideally spherical shape and uniform size. It’s found the polycarboxylate surfactant of SMA (styrene...

Preparation of mono-sized epoxy/MF microcapsulesin the appearance of polyvinyl alcohol as co-emulsifier

For epoxy microcapsules embedded in concrete as mechanic-triggered self-healing adhesive, globular shape with uniform size is the basic requirement to ensure the solid shell broken and the liquid core released at a designed stress. In this paper, monodispersed melamine–formaldehyde (MF) resin-walled epoxy E-51 microcapsules were successfully...

Preparation and characterization of poly (urea-formaldehyde) walled dicyclopentadiene microcapsules

Poly (urea-formaldehyde) (PUF) shelled dicyclopentadiene (DCPD) microcapsules were prepared by in-situ polymerization technology for self-healing concrete applications. It’s found, during the process, sodium dodecyl benzene sulfonate (SDBS) behaves better in emulsification of DCPD than other surfactant of sodium lauryl sulfate (SLS) and styrene...

Preparation and characterization of poly (urea-formaldehyde) walled dicyclopentadiene microcapsules

Poly (urea-formaldehyde) (PUF) shelled dicyclopentadiene (DCPD) microcapsules were prepared by in-situ polymerization technology for self-healing concrete applications. It’s found, during the process, sodium dodecyl benzene sulfonate (SDBS) behaves better in emulsification of DCPD than other surfactant of sodium lauryl sulfate (SLS) and styrene...

Self-encapsulation of epoxy resin by a controlled interface curing process in epoxy/water emulsion

The microcapsules of epoxy E-51 resin encapsulated by cured itself were prepared by interfacial curing reaction, in which ethylenediamine (EDA) was employed as curing agent and sulfonated copolymer of styrene and maleic anhydride (SMA) as emulsifying agent. It’s found the morphology of microcapsules strongly depend on reaction time and EDA...