A rubber particle anti-abrasive ultrahigh-performance concrete (UHPC) with a high strength, a low shrinkage, a high abrasion resistance, a high impact toughness and a high durability was developed to solve the problems of erosion damage of bridge pier in western mountainous areas with frequent floods. The mechanism of the surface modification of rubber particles to improve the properties of UHPC materials was investigated by scanning electron microscopy, energy spectroscopy and contact angle measurement. The results show that the anti-wearing strength and final crack impact energy are increased by 26% and 72%, respectively, after adding 10% (in volume fraction) NaOH + KH570 modified rubber particles with the sizes of 1-3 mm into UHPC. Also, the shrinkage is reduced by approximately 50% after adding 15% (in volume fraction) saturated pre-wet high-titanium heavy slag sand and 6% (in mass fraction) CaO type expansion agent into UHPC, compared to the reference UHPC. In addition, the modified rubber particles mainly improve the properties of UHPC material due to the improvements of the surface morphology of rubber particles, the surface hydrophilicity, and the interface properties of rubber particle-cementitious materials matrix.

Two kinds of emulsion organic silicon and two types of powder organic silicon, with different contents (0, 0.25%, 0.50%, 1.00%, in mass fraction) were mixed into concrete. The water absorption behavior of hydrophobic concrete internally incorporating organic silicon was investigated by contact angle, compressive strength and capillary absorption measurements. The results show that the effect of emulsion organic silicon on the compressive strength of concrete at the same age is less than that of powder after the addition of organic silicon. The concrete with 0.25% emulsion organic silicon has a little effect on its compressive strength during 28 d curing. The compressive strength is reduced by 0.5% and 7.8% when the water-cement ratio is 0.53 and 0.35, respectively. After a silicon membrane is formed on the concrete surface, the contact angle reaches over 100° and is not affected by further increasing admixture amount of organic silicon. In addition, compared to ordinary concrete, the amount of absorbed water is reduced by 60% at least and the water absorption rate is stabilized for 36 h after the addition of silicon into concrete.

Well-dispersive carbon nanotubes (CNTs)/polyvinyl alcohol (PVA) nano-colloidal emulsions were prepared based on the colloidal stability and interfacial chemistry. The effect of CNTs/PVA nano-colloidal emulsion on the mechanical properties, dry shrinkage and morphology of concrete was investigated. The results show that the 28 d compressive strength and flexural strength of concrete incorporating 0.3% (in mass fraction, the same below) CNTs and 1.0% PVA are increased by 10% and 15%, respectively, and the dry shrinkage rate of concrete containing 0.5% CNTs and 1.0% PVA after 7, 28, 180 d and 360 d curing is reduced by 76%, 34%, 22% and 21%, respectively, compared to the reference concrete. The effect of CNT-OH/PVA latex on the mechanical properties and dry shrinkage rate of concrete is attributed to the formation of CNTs/PVA interpenetrating networks in concrete, which prevents the concrete crack and refines the microstructure.

The effect of curing methods on the mechanical and microscopic properties of ultrahigh-performance concrete (UHPC) was investigated at different curing temperatures (i.e., 20, 40, 60, and 90 ℃) and with thermal insulation. The results show that the compressive strength of UHPC is positively correlated to the early curing temperature, but the difference decreases with the age. The 28 d compressive strength difference of UHPC is less than 4%, and the tensile strength is high after curing with thermal insulation or at 90 ℃ in early stage. The peak value of heat flow of each samples increases with the increase of the ambient temperature and occurs in advance, and the cumulative heat release becomes stable in a shorter time. At 4 d, the intensity of Ca (OH)₂ diffraction peak in UHPC matrix after curing with thermal insulation is reduced, compared to that after curing at 20 ℃, indicating that the admixture is well involved in the hydration. The mean chain length of Si-O chain in the C-S-H gel for UHPC after curing with thermal insulation in early age is similar to that for the samples after curing at 90 ℃, and the matrix density is extremely high.

The bonding performance of steel fibers (i.e., straight and hooked-end steel fibers) in hybrid steel fibers reinforced ultrahigh-performance concrete (UHPC) was investigated through single steel fiber pullout tests. Based on the load-displacement curves of steel fibers, the effects of hybrid steel fibers and their volume fraction on the bonding properties between hybrid steel fibers and UHPC were analyzed, and the correlation between the fiber-UHPC interfacial bonding properties and the compressive strength of UHPC was discussed. The pullout processes of steel fibers in hybrid steel fibers reinforced UHPC were clarified, and the pullout load-slip models of the straight and hooked-end steel fibers during the pullout processes were proposed. It is indicated that the hybrid of steel fibers could achieve an optimum interfacial bond performance between steel fibers and UHPC at the volume fraction of both straight and hooked-end steel fibers embedded in the UHPC matrix of 1%.

A coupled structural response vector (SRV) and support vector machine (SVM) approach was developed for the connection loosening detection of frame supported glass curtain walls. Firstly, a structural simulation model was established, which considered both static and dynamic characteristics for the connection damage due to the loosening effect of frame supported glass walls. Secondly, the structural response vector was then used for damage pattern identification and quantification, which validated the effectiveness and applicability of SRV as damage indicators. Finally, a damage identification sample database containing different SRVs with the first four frequencies of glass panels and the inclination angles at nine points was established. Three SVMs with different kernels functions were used for the sample training and damaged identification. Particle swarm optimization was also utilized to optimize the parameters of radial basis function kernel. The results show that the effectiveness of coupled SRV-SVM approach for the identification and quantification of connection loosening of frame supported glass curtain walls is satisfactory.

Hierarchical pore structure mullite ceramics with macro- and meso-pores were prepared by a foam-gelcasting method and a pore-forming agent method using SiC and CaCO₃ as additives. The effect of SiC amount on the flexural strength, compressive strength and thermal conductivities of porous ceramics was also investigated. The results show that porous mullite ceramics with a lot of close pores can be fabricated via the method with mullite powder as a raw material and CaCO₃ and SiC (0-8% (mass fraction)) as additives. The as-synthesized porous mullite ceramic prepared with 4% (mass fraction) SiC has 69.9% porosity and a lowest thermal-conductivity.

Calcite, quartz and Al₂O₃ were used as raw materials to prepared anorthite coating, and improving the flexural strength of porcelain tiles via residual surface compressive stress provided by regulating the composition of the coating. The effect of binders, Al₂O₃ content, modulus of elasticity of coating and the ratio of cross section between coating and substrate were studied on the preparation of coating and improving of flexural strength. The results are as follows: when the Al₂O₃ content a is 17.5%, 1% PVA is used as binder and the sintering process is kept at 1 200 ℃ for 0.5 h, an anorthite coating with a thickness of about 80 μm can be obtained. The hardness of the samples is 630 kg/mm² and the flexural strength increased by 72.6%, from (62±3) to (107±4) MPa.

An assisted identification method with artificial intelligence was proposed to identify the dating and authenticity of ancient ceramics with banana leaf pattern. The local binary patterns (LBP) and the histogram of oriented gradient (HOG) were used to extract the characteristics of the time from the banana leaf pattern of ancient ceramics images. The intelligent chronological identification of ancient ceramics was realized through the fusion of the local binary patterns features and the histogram of oriented gradient features of banana leaf pattern, and the similarity of ornamentation was used to measure the authentic and imitative possibility of ancient ceramics. The experiment was based on the ancient ceramic image database of the museum collections. The experimental results show that the proposed method can complete the accurate identification of ancient ceramics and find out the development law of banana leaf pattern, thus assisting experts in the identification of the ancient ceramics. In addition, the similarity analysis based on ornamentation features can provide a support for the authenticity identification of ancient ceramics.

(Li_0.5Bi_0.5)_xBa_1-xBi₈Ti₇O₂₇ intergrowth bismuth layered structure lead-free piezoelectric ceramics were prepared by a solid-state reaction method. (Li_0.5Bi_0.5)²⁺ co-doping can replace Ba²⁺ doping at A site in the system to regulate the crystal structure as well as increase the Curie temperature and the application range in the high-temperature field. The introduction of (Li_0.5Bi_0.5)²+increases the piezoelectric constant d₃₃ from 8 to 18.5 pC/N, and the Curie temperature from 480 to 633 ℃. Based on the result of XRD and Raman spectra, the degree of orthogonal distortion increases. The hysteresis loops show that the remanent polarization is related to the structural distortion, and the piezoelectric constant changes in the same way. (Li_0.5Bi_0.5)_0.6Ba_0.4Bi₈Ti₇O₂₇ ceramics with the optimum comprehensive electrical properties can be used as a potential candidate material for high- temperature piezoelectric field.