Textile reinforced ultra-high performance concrete (TR-UHPC) utilizes the synergistic reinforcing mechanism of short steel fibers and textile to further improve the mechanical properties and strain hardening effect of ultra-high performance concrete (UHPC). To investigate the flexural properties of TR-UHPC and synergistic effects of textile and steel fibers, four-point bending tests were conducted. A design method for TR-UHPC flexural members based on a tension-stiffening model and a bending model was proposed. The effect of tension-stiffening on the flexural responses of TR-UHPC was analyzed. The results show that the flexural capacity of TR-UHPC specimens increases with the increase of steel fiber dosage. The maximum flexural strength can be obtained at a steel fiber volume fraction of 1.0% or 1.5%, indicating that the content of steel fiber can be effectively reduced. The prediction data by the proposed model are in reasonable agreement with the experimental results. The proposed model can be used to predict the load capacity of TR-UHPC flexural member with given materials, or guide the material design according to the demands of structural performance.

In order to obtain a polycrystalline yttrium iron garnet ferrite (YIG) joint with both structural reliability and electromagnetic function matching, a new Bi₂O₃-B₂O₃-NiO-Fe₂O₃ glass is designed to fabricate YIG ferrite. The wettability of the glass on the surface of YIG ferrite, typical organization, the impacts of brazing temperature to the microstructure of the joint and mechanical properties is investigated. The result shows that the glass have a well wettability on YIG joint. Some Al was incorporated into the glass solution during melting process and replaced Fe³⁺ in NiFe₂O₄ and YFe₃B₄O₁₂. The growth of NiFe₂O₄ and YFe₃B₄O₁₂ is promoted due to the smaller radius of Al³⁺ and smaller lattice distortion. Small NiFe₂O₄ particles in the seam transform to large blocky organization as the temperature goes up, proving that high temperature has a positive effect on NiFe₂O₄ aggregation. The glass-YIG joint has a high shear strength and reaches its maximum of 71 MPa at 750 ℃, then the shear strength decreases with increasing temperature, dropping to 47 MPa at 800 ℃.

Steel slag multi-phased clinker is a cement clinker directly calcined by granular steel slag, so the physical and chemical characteristics of steel slag are very important to the sintering of multi-phased clinker. In order to explore the influence mechanism of different types of converter steel slag on the sintering and properties of multi-phased clinker, three kinds of multi-phased clinker were prepared by using hot smoldering slag, roller slag and pressurized hot smoldering slag at 1 420 ℃. The results show that the multi-phased clinker minerals with different steel slag were mainly C₃S, C₂S and C₄AF, the higher iron content in steel slag resulted in the Al transformed into ferrite minerals, showing a typical high ferrite (Ferrite content > 18%, mass fraction) characteristic. The differences of chemical composition, mineral composition and particle size distribution among different steel slag had different influences on the formation and development of mineral crystals and properties of multi-phased clinker. The content of water-soluble chromium (VI) in multi-phased clinker was positively correlated with the content of Cr₂O₃ and alkali in steel slag, and the higher the content of fine particles in steel slag, the more easily Cr was oxidized into water-soluble high valence chromate in the sintering process.

Using a new partial calcination strategy, which partially decomposes hydromagnesite into magnesium oxide at a lower temperature for a short time. It also explores the potential of preparing cementitious materials by mixing them with calcined clay. The research showed that in addition to MgO, partially calcined hydromagnesite also contained undissolved amorphous magnesium carbonate, which could enhance the rate of MgO hydrated into Mg(OH)₂ and significantly improved the early mechanical properties of the cementitious material, but the development rate of strength in the later stage decreased. Compared with completely calcined hydromagnesite, while the content of amorphous magnesium carbonate accounts for 3.0% of the total mass, the 1 day strength was increased by 167%. Partial calcination strategies can effectively reduce carbon emissions and improve the early strength of cementitious materials.

Transition metal sulfide is an active material with high specific capacitance. MnS/Ni₃S₂ electrode material was hydrothermal prepared on nickel foam by a simple and time-saving method. The effects of hydrothermal reaction time and temperature on the morphology and electrochemical performances of the sample were investigated. The results show that MnS/Ni₃S₂ electrode material has high specific capacitance and excellent magnification performance, and the retention rate of specific capacitance is 90% after 2 500 cycles. A hybrid supercapacitor device is assembled with MnS/Ni₃S₂ as the positive electrode and activated carbon (AC) as the negative electrode. MnS/Ni₃S₂//AC can provide 30.2 Wh·kg^-1 energy density when the power density is 700 W·kg^-1. The specific capacitance retention is 116.0% after 3 000 cycles. It shows that MnS/Ni₃S₂ is expected to provide potential application value in supercapacitor.

For the regular preparation techniques of ceramics, high-temperature sintering has always been a necessary condition to obtain dense microstructures and good properties. As a recently emerged technique, Cold Sintering Process (CSP) can achieve rapid densification for various ceramic materials at ultra-low temperatures (below 350 ℃) through dissolution-precipitation and other mechanisms. CSP has shown tremendous development space and high research potential by effectively solving the problems existing in conventional high-temperature sintering in terms of energy consumption, microstructural control and co-firing with organics. This review starts from the brief summary on the development history, technologic process and densification mechanisms of CSP. Then the application status of CSP on the preparation of ceramics (including bio-ceramic materials, new energy materials, semiconductor materials, dielectric materials, thermoelectric materials, unstable materials at high temperatures) is described, and its future development is prospected.

The scientificity of "recycled aggregate concrete" or "recycled concrete" is discussed. It is suggested that "recycled aggregate concrete" must be used.

The development of cohesionless cracks can be regarded as a sign of macroscopic crack development. An identification model of cohesionless cracks was adpoted with results of crack development by digital image correlation (DIC) method. Three-point bending tests were carried out on fully-graded concrete specimens with different loading rates (0.000 1 mm/s, 0.001 0 mm/s, 0.010 0 mm/s), considering the rate correlation of crack propagation of fully-graded concrete. The results show that for the fully-graded concrete specimens with different loading time intervals, cohesionless cracks will occur throughout the peak load, indicating that the prefabricated cracks have cracked when the peak load is reached. The cracks of the specimen is mainly concentrated after the load is loaded to 50% of the peak load. Under the same conditions, the slower the loading rate is, the earlier the unbonded cracks appear. With the increase of the loading rate, the cracks are thin and long.

Accurate identification and quantification of pores and microcracks in lightweight aggregate concrete (LAC) are important for analyzing salt frost deterioration mechanisms. Therefore, a new DIP method based on morphology principle was proposed, which overcomes the difficulties of traditional methods that can not accurately segment pores and microcracks because of only relying on shape factors, and the porous lightweight aggregate interferes with the analysis of pore and microcrack in concrete matrix. Using this method, the microstructure deterioration of shale ceramsite LAC and normal aggregate concrete (NAC) with same mortar to aggregate ratio and same water to cement ratio was compared and analyzed. With the increase of freeze-thaw cycles, the pore structure damage of the two concretes is manifested as pore expansion and microcrack initiation from the pore wall, leading to the relative dynamic modulus of elasticity (r_n) loss. Grey correlation analysis indicates that in addition to the initiation and propagation of microcracks, the high dispersion of LAC pore diameter also contributed to the loss of r_n in LAC. Test shows the new DIP method realizes the segmentation and independent analysis of pore and microcrack, and achieves the recognition accuracy to 10.6 μm, which has advantages in quantitative analysis of concrete pore structure and microcracks.

To study the promotion process of cement hydration by polycarboxylate superplasticizers modified calcium silicate hydrate (C-S-H/PCE) and understand the mechanism of C-S-H/PCE seeds promotion of cement hydration. Acrylic acid-based polycarboxylate superplasticizer (PCE-1) and silane-based polycarboxylate superplasticizer (PCE-2) were used to surface modify the hydrothermal synthesized calcium silicate hydrate (C-S-H/Unmodified) seeds, resulting in the polycarboxylate superplasticizer modified C-S-H seeds (C-S-H/PCE-1 and C-S-H/PCE-2). Subsequently, these three C-S-H seeds were added to the cement paste. The compressive strength, phase composition, and heat release curve of cement paste and the surface tension of C-S-H seeds were tested. The results showed that the surface modification of PCE-1 and PCE-2 resulted in an increase in the surface contact angle of C-S-H seeds from 36.9° to 41.1° and 42.9°, resulting in lattice mismatch of the sedimentary phase (hydration product) on the surface of the substrate material (C-S-H seeds) and inhibiting the epitaxial growth of cement hydration products on the surface of C-S-H seeds. PCE modification reduced the promoting effect of C-S-H seeds on the hydration process of Portland cement. Moreover, the degree of reduction in the hydration promoting effect of C-S-H/PCE-2 on Portland cement is significantly greater than that of C-S-H/PCE-1 crystal nucleus. Tests of the adsorption equilibrium of PCE in the pore solution indicated that the C-S-H/PCE seeds did not directly introduce new crystal nucleation sites but exposed new C-S-H surfaces through the desorption of PCE on the surface of C-S-H/PCE seeds. The desorption degree of PCE on the surface of C-S-H/PCE seeds determined the promoting effect of C-S-H/PCE seeds on cement hydration.