Interpretation of the early stiffening process in alkali-activated slag pastes

To better understand early stiffening of AAS pastes, distinctive microstructural features by varying the silicate modulus (Ms) have been visualized with in-situ microscopy. In addition, the activation reaction was monitored with multiple approaches, while solid and liquid phases in hydrating AAS were characterized separately. In silicate...

Investigation of the hydration properties of cement with EDTA by alternative current impedance spectroscopy

Alternative current impedance spectroscopy (ACIS) is a promising non-destructive testing method to monitor long-term change and assess the durability of concrete. This study investigates the influences of Ethylene Diamine Tetraacetic Acid (EDTA) on the hydration of hardening cement by ACIS. It is found that EDTA retards the early-age...

Characterization of one-part alkali-activated slag with rice straw ash

In this paper, fresh (setting and rheology) and hardened properties (strength and shrinkage) of one-part alkali-activated slag (AAS) with and without rice straw ash (RSA) are comprehensively investigated. The reaction kinetics and microstructure of the mixtures are characterized by a series of experimental techniques. The results reveal that...

Fracture properties and microstructure formation of hardened alkali-activated slag/fly ash pastes

This study presents a comprehensive experimental investigation on the fracture properties of hardened alkali-activated slag/fly ash (AASF) pastes in relation to the microstructure formation and reaction product composition. The main reaction product in AASF is C-(N-)A-S-H gel along with minor hydrotalcite phase, with the polymerization of C-...

Internal curing of alkali-activated slag-fly ash paste with superabsorbent polymers

This study investigates the influences of internal curing on reducing the autogenous shrinkage of alkali-activated slag/fly ash (AASF) paste. The influences of internal curing with superabsorbent polymers (SAPs) on the reactions and microstructure of AASF paste are investigated. It is found that the SAPs absorb liquid mainly before the...

Unravelling the abrasion resistance of two novel meta-stable titanium alloys on the basis of multi-pass-dual-indenter tests

Multi-pass-dual-indenter (MPDI) scratch tests with various loading conditions were performed on two newly developed titanium alloys (Ti–10V–1Fe–3Al and Ti–10V–2Cr–3Al) to investigate their abrasion resistance under repetitive local sliding contact. A technically pure titanium sample was used as the reference. Various microstructures were...

Microstructure and hardness of SAC305 and SAC305-0.3Ni solder on Cu, high temperature treated Cu, and graphene-coated Cu substrates

In this study, SAC305 and SAC305-0.3Ni solder balls were soldered onto Cu, high temperature treated Cu (H-Cu) and graphene coated Cu (G-Cu) substrates, respectively. The microstructure, the interfacial reaction, and the hardness of the solder joints were investigated. The interfacial intermetallic compound (IMC) is Cu₆Sn<sub>5</sub...

Improvement of the Oxidation Resistance of the Single-Crystal Ni-Based TMS-82+ Superalloy by Ni–Al Coatings with/without the Diffusion Barrier

Oxidation behavior of the uncoated base, Ni–Al coated and Re–Cr-Ni plus Ni–Al coated single-crystal (SC) Ni-based TMS-82+ superalloy is studied under cyclic air at 900ºC for 200 h to assess the oxidation resistance. Regardless of the coating processing, Ni–Al coating is effective in improving the oxidation resistance due to the formation of a...