Using XRD and SEM analysis, the types and morphology of autoclaved aerated concrete (AAC) hydration products in different water-to-binder ratio (w/b) and different autoclaved system were studied. Strength test shows that, Using w/b=0.25 and autoclaved curing 190°C for 8h, AAC with dry density 765kg/m3 and compressive strength 7.5MPa was made. XRD and SEM analysis indicate that, the higher the autoclaved temperature is, the smaller the size of hydration products (most of them are tobermorite and hydrogamet) is, and the crystallinity has a little increase; with the extension of autoclaved time, the size of products is smaller, the crystallinity is first increased and then decreased, the crystal form of tobermorite turns 1.1nm into 1.4nm; the less the w/b is, the smaller the size of products is, and the higher the crystallinity is, and tobermorite turns 1.1nm into 1.4nm.

In ordinary processing condition, using small amount (2%) of polymer to modify reactive powder concrete (RPC), the performance of modified and unmodified RPC was studied for their corrosion resistance with water-dip-in, acid-dip-in and sulphate solution-dip-in tests and was verified by the strength loss rate. The results show that not only the corrosion resistance but also the strength, especially the flexural strength, has been improved obviously after the polymer modification. The mechanism has been studied with SEM and EDS analysis.

Background: Binary metal oxides, such as spinel nickel cobaltite (NiCo2O4), are attractive pseudocapacitive materials in electrochemical supercapacitors because they have higher theoretical capacitance than carbonaceous materials, and higher electronic conductivity than conventional monometal oxides. However, their practical pseudocapacitive performance is dramatically hindered by traditional electrode assembly technologies, through which extremely high internal resistances are generated at supplementary interfaces within nanostructured binary metal oxides and between binary metal oxides/current collector. Methods: Here, we develop polymer-binder-free hybrid electrodes by employing Ni nanotube arrays as 3D current collectors for the loading of electroactive NiCo2O4 nanosheets (Ni/NiCo2O4 nanotube array). Results: As a result of the remarkably enhanced electronic conductivity and ion diffusion, the Ni/NiCo2O4 nanotube array electrodes exhibit a specific capacitance of as high as ~753 F g-1 at a scan rate of 5 mV s-1 and rate performance, in addition to a long-term cycling stability. Conclusion: The outstanding performance makes the Ni/NiCo2O4 nanotube array to be an efficacious power source electrode in a wide range of applications.

At present, masonry and plaster of AAC blocks are still carried out by traditional construction methods which often lead to some quality defects such as cracking and leaking in the wall and hollowing and spalling in the plaster layer, etc. and hinder greatly the popularization and application of AAC blocks. On the basis of the characteristics of AAC blocks and the dry masonry thin-bed mortar, a kind of high performance dry-mixed Mortar for dry masonry process of AAC blocks was developed. The mortar has excellent workability, high water-retention, property, good mechanical properties and good construction properties. It solves the problems caused by traditional construction methods. The mechanism for these is discussed.

Feasibility study of partially replacement of cement and ground sand by ground steel slag (GSS) and ground granulated blast furnace slag (GGBFS) in producing prestressed high strength concrete pile (PHC) was conducted. The results showed that under normal curing（20oC, 95% RH）and the steam curing condition (80oC), GSS possessed less reactivity than GGBFS. However, under autoclave curing condition (180 °C, 1.0MPa), the reactivity of GSS can be effectively activated. The autoclaving strength of the concrete made from 20% GSS with Blaine 550m2/kg, 55% cement and 25% ground sand could reach 89.0 MPa which is not only higher than that of GGBFS (82.8MPa), but also higher than that of traditional PHC concrete (83.9Mpa, 70% cement and 30% ground sand). It’s feasible to produce PHC concrete by GSS with high fineness and optimized dosage.