Journal of the Chinese Ceramic Society
Co-Editors-in-Chief
Nan Cewen
2022
Volume: 50 Issue 2
33 Article(s)
LAI Yinan, XIONG Jie, HAO Yanan, and TAN Yeqiang

Applications, evaluations, funding, and management of National Natural Science Foundation of China programs on inorganic nonmetallic materials in 2021 were summarized and statistically analyzed. The specific measures of inorganic nonmetallic materials on scientific fund reform, talents and academic teams, academic exchange and seminars, in-depth researches on the 14th five-year and medium and long-term development plan were introduced detailedly.

Nov. 23, 2022
  • Vol. 50 Issue 2 277 (2022)
  • WANG Bochong, HAO Chunxue, CHANG Yukai, MOU Congpu, WEN Fusheng, and LIU Zhongyuan

    Microwave absorbing materials are widely used in military and civil fields. The current research focusses on novel microwave absorbing materials with intense absorption, wide bandwidth, light weight and thin thickness. Black phosphorus (BP) and sulfur-doped black phosphorus (BP-S) crystals were prepared at a high temperature and a high pressure, and then BP and BP-S nanosheets were obtained via liquid-phase exfoliation. Compared with BP, the complex permittivity and εr″/εr′ of BP-S are enhanced at 1.0-16.5 GHz. The minimum reflection loss (RL) reaches -41.4 dB at 9.6 GHz, and the RL exceeding -10 dB in a frequency range of 7.0 to 16.1 GHz is obtained for the absorber thickness of 1.0-2.0 mm. The minimum RL frequency dependence of the absorber thickness for BP-S comply with a λ/4 matching model. BP-S has broad application prospects as a high-performance microwave absorbing material.

    Nov. 23, 2022
  • Vol. 50 Issue 2 285 (2022)
  • YANG Zhongwei, LIU Lin, YU Xin, and LIU Hong

    The mechanism of conventional photocatalysis is based on photodegradation effect of photo-induced carrier when the surface of photocatalyst nanoparticles is irradiated by light. For this photocatalysis technique with outside-light-supply mode, a light utilization efficiency is rather low, the catalyst is often out-of-work, and recycle cast is high, which restrict its practical application in environmental protection. To solve the problems above, a photocatalytic system was prepared via the construction of a non-crystal fiber-Sn3O4 nanosheet. The results show that Sn3O4/optical fiber in the photocslayst can enhance the photocatalytic performance. In addition, the wave guide of incoherent light targeted to photocatalysis and the inner-light-supply photocatalysis were also proposed for the development of optical wave guide theory, and this photocatalyst with Sn3O4/optical fiber could have a promising potential in water treatment application.

    Nov. 23, 2022
  • Vol. 50 Issue 2 290 (2022)
  • WANG Zhongwei, LUO Hongjie, HUANG Xiao, ZHAO Jing, LI Qiang, YANG Longkang, and GAO Ge

    The salt control and desalination for treating the secondary damage of silicate materials caused by sticking ointment and soaking method commonly used in salt damage control were investigated by a spraying atomized water vapor method. The salt distributions in the samples before and after treatment were analyzed by laser particle size analysis, X-ray diffraction, visible shortwave infrared hyperspectral imaging analysis and ion chromatograph. The results show that after the atomized water vapor enters the sample, the area where the sample is wetted is a hemisphere centered on the spray point, and the salt in the superficial layer of the sample is transported to the outside of the hemispherical wetting area. Also, the route of controlling the salt distribution by atomized water vapor was proposed, and the feasibility of preventive treatment of salt damage in silicate material was preliminarily verified.

    Nov. 23, 2022
  • Vol. 50 Issue 2 298 (2022)
  • ZHAN Ruonan, DI Chen, GENG Zhiming, ZHANG Enrui, YUAN Ziyuan, YAN Xuejun, ZHAO Yang, YAO Shuhua, LU Hong, and LU Minghui

    With the developments of the electronics and energy technologies, studies on nanostructure engineering of the emerging thermoelectric materials and thermal logic devices are drawing increasing attentions. In this review, we focus on several promising thermoelectric materials, and study the mechanisms of thermal transport engineering in the atomic and nano-scale structures theoretically and experimentally, with a micro-nano scale thermal transport measurement system developed by our research group. Such research focuses include: the atomic alloying of Si1-xGex alloy films with full components, the mismatched interfaces of Bi2Ca2Co2Oy layered-structure single crystals, the ionic localized resonances of superionic conductor A0.5RhO2 (A=K, Rb, Cs) single crystals, and the loose microstructures in quasi-one-dimensional ZrTe5/HfTe5 single crystals as well as the SnSe2 intercalations in SnSe single crystals. The influences of various scale structures and interatomic forces on the thermal transport properties are summarized, offering effective engineering strategies on developing potential thermoelectric materials with low thermal conductivity and excellent thermoelectric performance. Besides, the realization of effective dynamic engineering of thermal conductivity using phase transition, along with its potential applications in thermal logic devices are introduced.

    Nov. 23, 2022
  • Vol. 50 Issue 2 307 (2022)
  • DENG Zhi, LI Shuai, HAN Jiantao, and ZHAO Yusheng

    All-solid-state batteries are considered as one of the most promising next-generation energy storage technologies due to their superiorities of high safety and high energy density. As the core component of all-solid-state batteries, solid-state electrolytes are of great importance for the development of all-solid-state batteries. As a novel family of solid electrolytes, lithium/sodium-rich anti-perovskites have attracted much attention due to their good comprehensive performances. In this review, the latest research progress on lithium(sodium)-rich anti-perovskite solid electrolytes during recent years was represented.

    Nov. 23, 2022
  • Vol. 50 Issue 2 321 (2022)
  • ZHANG Zhengyan, PAN Zhenxiao, and ZHONG Xinhua

    Quantum dot-sensitized solar cells (QDSC) have attracted extensive attention because of their high efficiency and low-cost potential. In the past five years, the power conversion efficiency (PCE) of QDSC has developed rapidly from less than 10% to more than 15%, showing a promising application prospect. Among them, the design and exploitation of infrared absorption CuInSe2-based quantum dot light-harvesting materials and the significant increase in loading amount promote a rapid promotion for the PCE of QDSC. This review summarized recent work on the design and exploitation of CuInSe2-based QD light-harvesting materials as well as the strategies for high QD uploading.

    Nov. 23, 2022
  • Vol. 50 Issue 2 331 (2022)
  • DU Peng, JIA Feihan, LU Xiaolei, and CHENG Xin

    Sulphoaluminate cement is widely used due to its characteristics of short setting time, high early strength, high erosion resistance, low permeability and low-temperature calcination. However, the excessively high cost of raw materials restricts the development/application of sulphoaluminate cement. This review represented recent research work on the use of solid waste to calcinate sulphoaluminate cement clinker, and discussed the effect of calcining process on the appearance of clinker, mineral composition and mechanical properties of cement. Also, the current popular options of solid waste and their feasibility as raw materials for calcining sulphoaluminate cement clinker were introduced. The hydrating capacity of the cement was summarized. The results of the current research were analyzed. The existing problems and development directions were given to provide references for further research and application.

    Nov. 23, 2022
  • Vol. 50 Issue 2 340 (2022)
  • Nov. 23, 2022
  • Vol. 50 Issue 2 1 (2022)
  • LIU Xiaorong, and WANG Ru

    The effect of styrene acrylic (SA) copolymer on the early hydration of calcium sulphoaluminate-anhydrite composite was investigated by calorimetry, X-ray diffraction, thermogravimetic analysis, scanning electron microscopy, and inductively coupled plasma-optical emission spectroscopy. The results show that SA can delay the hydration process, reduce the content of ettringite (AFt), single sulfur calcium sulphoaluminate hydrate (AFm) and Al(OH)3 (AH3) in the accelerated hydration period, and promote the reaction of AH3 with anhydrite and calcium hydroxide to form AFt as well as the transformation of AFt to AFm in the late hydration period. Also, SA can rapidly reduce the surface tension of the pore solution, and the surface tension tends to be stable within the hydration reaction. SA can increase the pH value of the pore solution, increase the concentration of OH- and affect the concentration of Ca2+, SO42- and [Al(OH)4]- in the composite, and decrease the ion concentration and the precipitation rate of hydration products at the initial stage of hydration, thus delaying the hydration process and reducing the hydration products.

    Nov. 23, 2022
  • Vol. 50 Issue 2 354 (2022)
  • WANG Ming, FANG Pengfei, DU Liang, QI Pengtao, and SHEN Ding

    A composite of porous carbon coated Li4Ti5O12 was prepared by a hydrothermal synthesis and high-temperature activation method. The microstructure and electrochemical properties of the composite were investigated. The results show that Li4Ti5O12 is completely coated on the porous carbon layer. Meanwhile, the surface pores of Li4Ti5O12@porous C composite are evenly distributed, and the carbon layer thickness is approximately (8.5±3.6) nm. The discharge capacity at first cycle is 363 mAh/g, which is approximately twice greater than that of pure Li4Ti5O12. The AC impedance value of Li4Ti5O12@porous C composite decreases, which is only the half of that of pure Li4Ti5O12. The discharge specific capacity of Li4Ti5O12@porous-C composite is 251 mAh/g and the retention rate is 97.7 % after 200 cycles (i.e., the specific capacity of pure Li4Ti5O12 is 143 mAh/g and the retention rate is 94.7%), the discharge specific capacity is nearly doubled, especially when the rate test is carried out at different discharge rates. The reversible capacity is twice greater than that of Li4Ti5O12. The porous carbon coated modification of Li4Ti5O12 can increase the specific surface area and the electron transfer rate for the higher electrochemical properties.

    Nov. 23, 2022
  • Vol. 50 Issue 2 364 (2022)
  • HE Jin, WANG Mingzhong, CHEN Zhihong, LI Shuzhi, XU Yinsheng, and LU Ping

    Lithium-aluminosilicate glasses with different zirconia (ZrO2) concentrations were prepared by a melting-quenching method. Glass slices were treated using a two-step chemical strengthening method below glass transition temperature (Tg). The effect of ZrO2 addition on the glass stability, hardness and chemical strengthening performance was investigated. The results show that the Tg increases with the increase of ZrO2 concentration in the range of 0-5% (in mole fraction). The absence of crystallization peaks indicates these glasses are rather stable. An appropriate addition of ZrO2 can promote the Li+-Na+ ions exchange and increase the layer depth. The surface compression stress (σc) increases with the increase of the ZrO2 concentration and reaches a maximum value of 1 055.6 MPa at 4% ZrO2 concentration. The center tension firstly increases and then decreases slightly with the increase of the ZrO2 concentration, indicating that these glass samples have a good shock resistance. The addition of ZrO2 has little effect on the hardness of glasses after chemical strengthening. Although the addition of ZrO2 decreases the crack resistance, these glasses still have a good crack resistance performance after chemical strengthening.

    Nov. 23, 2022
  • Vol. 50 Issue 2 372 (2022)
  • CHEN Chunyu, HU Hao, ZHONG Cong, LIU Xueliang, and ZENG Huidan

    Phosphosilicate glasses are widely used in optical fiber, biological materials and other fields because of their excellent optical properties and biological activity. The influence of Li2O content on the microstructure and diffusion properties of Na2O-Al2O3-SiO2-P2O5 glass was investigated via molecular dynamics simulation, and the relationship among the microstructure, Vickers hardness and diffusion coefficient was analyzed. The results show that the degree of phosphorus network polymerization (QP) increases with the substitution of Li2O for Na2O, and the hardness increases with the increase of QP. The self-diffusion of Li+ ions is greater than that of Na+ ions, indicating that Li+ ions are easier to diffuse rather than Na+ ions. The potential barrier of Li+ ions decreases with the increase of Li2O. Li2O is beneficial to the substitution of Na2O for the diffusion of Li+ ions.

    Nov. 23, 2022
  • Vol. 50 Issue 2 378 (2022)
  • CHEN Yuliang, LIU Jie, WU Huiqin, JIANG Rui, and YAN Fang

    To investigate the effects of replacement rate and sample size on the direct shear performance and damage of recycled aggregate concrete (RAC), 45 RAC specimens were manufactured. The failure modes of RAC with different sizes were characterized, and the effects of replacement rate and specimen size on the direct shear performance and damage constitutive model of RAC with different sizes were investigated via direct shear tests. The results show that the peak deformation and ductility coefficient have a size effect, the damage development rate of natural concrete becomes slow, and the damage development rate of RAC becomes faster. The peak deformation firstly decreases and then increases, while the ductility coefficient firstly increases and then decreases with the increase of the replacement rate. The damage development law does not have a linear relationship with the replacement rate. The constitutive model can well reflect the shear load-deformation relationship and the damage evolution process of the RAC with different sizes.

    Nov. 23, 2022
  • Vol. 50 Issue 2 388 (2022)
  • XIE Jing, ZHANG Xuanhan, and LONG Wujian

    The mechanical properties, hydration process and microstructure characteristics of the calcined hydrotalcite modified cementitious material at different fly ash contents were analyzed. Based on the results by the compressive strength test calcined hydrotalcite can greatly improve the compressive strength of cement-fly ash mortar. The phase composition of hardened cement paste was characterized by X-ray diffractionand and thermogravimetric analysis. The results show that calcined hydrotalcite can promote the hydration of cement-fly ash cementitious materials, thereby increasing the content of hydration products. It is incidiacted that calcined hydrotalcite can accelerate the dissolution of fly ash, and its nucleation effect is beneficial to the formation of hydration products.

    Nov. 23, 2022
  • Vol. 50 Issue 2 396 (2022)
  • WANG Shaowei, XIAO Yanyu, XU Yingli, ZHU Pinghua, and LIU Hui

    To quantify a relationship between the accelerated calcium leaching effect and the concentration of nitric acid solution ranging from 0.01 to 0.50 mol/L, leaching experiments and numerical simulation were conducted for cement paste, mortar and concrete specimens at a water-cement ratio of 0.50, and the evolutions of the macro- and micro-leaching indicators were analyzed. The results show that the proportional coefficients in Fick's diffusion law based on leaching depth and cumulative relative leached calcium ion exhibit a linear and negative exponential growth relationship with the concentration of nitric acid solution. The diffraction peak of calcium carbonate at the same depth of each leached paste specimen linearly decreases. The equivalent accelerated diffusion coefficients of cement paste, mortar and concrete are linearly proportional to the concentration of nitric acid solution, and the acceleration ratios are 3.9×103, 1.6×103 and 1.0×103 times of the concentrations (measured in mol/L), respectively. For cement paste with a water-cement ratio of 0.50, acceleration ratios of 6.00 mol/L ammonium nitrate, 0.50 mol/L nitric acid, 6.00 mol/L ammonium chloride and deionized water are 4 507, 2 018, 464 and 47, respectively. The equivalent accelerated diffusion coefficient of cement paste is 2.3 times greater than that of the concrete at the same water-cement ratio. If the concentration of chemical immersion solution is too high, the calcium dissolution-diffusion process will deviate from the dissolution mechanism in fresh water environment. When nitric acid solution is used for an accelerated calcium leaching experiment, an appropriate concentration is 0.10 mol/L.

    Nov. 23, 2022
  • Vol. 50 Issue 2 403 (2022)
  • LIU Guojian, ZHU Hang, ZHANG Yunsheng, LIU Zhiyong, SHE Wei, YANG Lin, and LIU Cheng

    Corrosion behavior and evolution of steel reinforcement in simulated concrete pore solutions subjected to different corrosive ions (i.e., chloride, sulfate, chloride-sulfate, and simulate sea water) were investigated. Corrosion products induced with chloride and sulfate ions were also analyzed, respectively. The results show that the presence of sulfate ions in co-existence scenario of chloride-sulfate ions lead to a lower polarization resistance and a higher corrosion current density. The steel corrosion potential is correlated to the polarization resistance evolution as a power function relationship. Corrosion products induced by chloride and sulfate ions depicts a slight difference, mainly containing γ-FeOOH, α-FeOOH, Fe(OH)3, Fe2O3 and FeO.

    Nov. 23, 2022
  • Vol. 50 Issue 2 413 (2022)
  • ZHANG Yi, ZHU Yanmei, REN Qiang, and JIANG Zhengwu

    To ascertain the influences of bentonite and its content on the printability of 3D printing mortar, the extrudability of mortar was evaluated via fluidity, and its buildability was evaluated by height retention rate and penetration resistance. Also, the rheological behavior of cement pastes with bentonite was characterized via dynamic and static shear tests. Effects of bentonite and its content on the printability of mortars were analyzed via rheology. The results show that the fluidity of printable mortars is linearly correlated to the plastic viscosity of cement pastes and logarithmically to the dynamic yield stress of cement pastes. Besides, there is an exponential relationship between the height retention rate of printable mortars and the static yield stress of cement pastes. The addition of bentonite in the mortar increases the plastic viscosity and dynamic yield stress of cement pastes, resulting in a decrease in the extrudability of mortar. Also, the addition of bentonite improves the static yield stress and structural rebuilding rate of cement pastes, thereby improving the buildability of mortar. Therefore, appropriate amount of bentonite can make the mortar maintain good extrudability while improving its buildability. A width ratio between the top and bottom layers of the printed sample with 2% bentonite is 0.96.

    Nov. 23, 2022
  • Vol. 50 Issue 2 420 (2022)
  • KAN Lili, WANG Fei, WU Haijiang, and DUAN Xinzhi

    The hydration degree and mechanical properties of ultra-high performance concrete (UHPC) specimens with hybrid steel fibers cured in air and hot water (1 d, 60℃ hot water + 2 d air), respectively, were investigated via ignition loss tests and uniaxial tensile and compressive tests. Also, the surface cracking characteristics of tensile specimens were characterized by digital image correlation technique and optical microscopy, and the microstructures were analyzed by scanning electron microscopy. The results show that compared with the results obtained in air curing, hot water curing accelerates the hydration reaction progress of the UHPC matrix, and an increase in temperature mainly contributes to the promotion of hydration reaction, thus improving the initial cracking, tensile and compressive strength of the UHPC specimens in hot water curing. However, the tensile strain capacity changes slightly. In general, the maximum crack width of the specimen decreases, the matrix becomes denser, and the interface bonding between the fibers and the matrix is stronger. The tensile strain of UHPC increases with the increase of fiber content, in which the tensile strains of the specimens with 2.5% (volume fraction) of fibers (a ratio of long fibers to short fibers is 1.25: 1.25 and 1.5: 1.0, respectively) are more than 2 ×10-3, the specimen with 1.5% long fibers and 1.0% short fibers produces more tensile cracks with the width of < 50 μm in hot water curing. The uniaxial tensile strains predicted by DIC are in reasonable agreement with the strains measured.

    Nov. 23, 2022
  • Vol. 50 Issue 2 429 (2022)
  • SU Jie, SHI Caijun, LU Feiyang, and FANG Zhi

    Ultra-high performance concrete (UHPC) prismatic specimen with different water-binder ratios, coarse aggregate contents, steel fiber volume fractions, and specimen dimensions were prepared. The influences of water-binder ratio, coarse aggregate content and steel fiber volume fraction as well as the scale effect on the flexural tensile strength of UHPC containing coarse aggregate were investigated. The results show that the flexural tensile strength of UHPC containing coarse aggregate decreases with the increase of the water-binder ratio and the coarse aggregate content. The scale effect on the flexural tensile strength of UHPC containing coarse aggregate is greater than that of UHPC without coarse aggregate. The scale effect on the flexural tensile strength of UHPC containing coarse aggregate decreases gradually with the increase of water-binder ratio. The scale conversion coefficient of flexural tensile strength of UHPC containing coarse aggregate and the parameter calculation formula of scale effect law were proposed for predicting the flexural tensile strength of UHPC with coarse aggregate.

    Nov. 23, 2022
  • Vol. 50 Issue 2 438 (2022)
  • LIU Ming, ZHANG Lei, YANG Wen, GAO Yuxin, ZENG Chao, LUO Yaoling, YE Zi, WANG Futao, and YAN Songling

    To improve the working performance of ultra-high performance concrete (UHPC), two kinds of water reducers with different structures, i.e., polyoxyethylene (EO) polyether (PCE-1) and propylene oxide block polyoxyethylene (EO/PO) polyether (PCE-2), were prepared. The performance of cement-silica fume slurry in a low water-binder ratio with two water reducing agents was evaluated via slurry fluidity, slurry viscosity test, total organic carbon test, and surface tension test, and the relevant mechanism was discussed. The results show that at PCE-2 in the slurry at 0.16 of water-binder ratio and 5%-25% of silica fume content (in mass fraction) has an adsorption-dispersion effect on silica fume rather than PCE-1, thus increasing the fluidity of cement-silica fume slurry. The block polyether structure of water reducer can adjust the surface tension and viscosity of the interstitial fluid, and reduce the viscosity of the cement-silica fume slurry.

    Nov. 23, 2022
  • Vol. 50 Issue 2 445 (2022)
  • YAO Shun, HU Chuanlin, HE Yongjia, and WANG Fazhou

    Cement-based materials are brittle and easy to crack, which are concerned as the key problems to be solved in engineering application. The microscale brittleness of the material phases of cement-based materials needs to be investigated, and a relationship between the micro-scale brittleness and the overall brittleness needs to be established for the toughening design of cement-based materials. In this work, the fracture toughness-displacement curves were obtained via micro-scratch test, and the phases corresponding to the scratch area were analyzed by high resolution scanning electron microscopy, thus charactering quantitatively the fracture toughness of cement paste and its material phases, and establishing the relationship between the overall brittleness of cement paste and the brittleness of calcium silicate hydrate gel.

    Nov. 23, 2022
  • Vol. 50 Issue 2 452 (2022)
  • MU Yuandong, LIU Zhichao, and WANG Fazhou

    Carbonatable calcium silicate cementitious material is a novel low-carbon building material with a great potential for development. γ-dicalcium silicate is one of the most carbonation reactive minerals among calcium silicates. In this paper, a wet powder of γ-dicalcium silicate was used as an experimental material. The influences of reaction duration, particle size, relative humidity, temperature, partial pressure and water-to-solid ratio on the degree of carbonation were investigated. The carbonation kinetic equation was proposed based on the modified shrinking-core model and empirical equation. It is indicated that the data predicted by the kinetic model are in reasonable agreement with the experimental results. The obstruction of ions diffusion attributed to the coating of carbonation products is a major factor of controlling the carbonation reaction.

    Nov. 23, 2022
  • Vol. 50 Issue 2 457 (2022)
  • DU Yuanbo, and GE Yong

    The thermal conductivity of cement paste with different water-cement ratios and curing ages were measured. Moreover, the thermal conductivity of cement paste was predicted by parallel model, series model, Maxwell model, MT model, EMT model and SC model, respectively. In addition, the thermal conductivity of each phase in cement paste was calculated by a molecular dynamics method. The results show that the thermal conductivity of cement paste decreases with the increase of curing age and water-cement ratio. SC model can be used to predict the thermal conductivity of cement paste at different water-cement ratios or curing ages, and the relative error between the predicted and the experimental values is 0.3%-4.7%. The Maxwell model and MT model can be used to calculate the thermal conductivity of cement paste at a large water-cement ratio and a long curing age.

    Nov. 23, 2022
  • Vol. 50 Issue 2 466 (2022)
  • FANG Zhi, ZHU Qimu, LIU Shaokun, and TAN Xingyu

    The fatigue properties of ultra-high performance concrete (UHPC) at 20 ℃ and -10 ℃ were investigated via flexural fatigue tests under different stress levels. The results show that, the degradation of UHPC flexural fatigue performance and the fatigue strength decrease under a cyclic load with the decrease of temperature due to the cold brittleness characteristics of steel fibers at the cracked section. Compared with the test results at 20 ℃, the fatigue strength of UHPC at -10 ℃ is decreased by 15.6%. Although the fatigue strength of the specimens at a low temperature is lower than that of the specimens at normal temperature, their fatigue deformation modulus ratios (En/E0) corresponding to their fatigue strengths are similar, which are 0.48. The residual strength of UHPC specimens undergoing 2 million cycles without flexural fatigue failure is close to the static strength under monotonic loading, at normal temperature or low temperature. Based on the results, a model of predicting the fatigue life of UHPC at 20 ℃ and -10 ℃ was proposed, and the predicted results could be used as reference in the practical application.

    Nov. 23, 2022
  • Vol. 50 Issue 2 473 (2022)
  • ZHU Yuhan, YANG Jian, WANG Xing-er, ZHANG Kai, and WANG Yige

    The residual effect of fractured glass, which is greatly affected by its fracture morphology, is correlated to the post-fracture performance of laminated glass. For tempered glass in laminated glass, its fracture morphology is affected by some major variables such as surface compressive stress, thickness, and fracture point. However, a few previous work concerning the fracture morphology characterization are reported. In this paper, fragmentation tests were firstly conducted on 81 tempered glass specimens. The fracture morphology and spatial distribution, including fragment area, perimeter, circularity and distribution intensity, were analyzed. The fracture morphology and spatial distribution obtained at the given variables (i.e., surface compressive stress of 60-105 MPa, thickness of 6-12 mm, three fracture points) were discussed. Also, a new seeds generation approach for the centroid of fragments to control nearest neighbor distance and global distribution intensity of fragments was proposed, which was combined with the Voronoi tessellation to characterize the fracture morphology of tempered glass. The proposed method has a satisfactory accuracy in generating the fracture morphology.

    Nov. 23, 2022
  • Vol. 50 Issue 2 482 (2022)
  • HE Bei, CHEN Qing, HE Li, SONG Facheng, and JIANG Zhengwu

    In order to prevent and control the corrosion damage of concrete structure caused by the stray current generated of metro operation, a high-impedance and ultra-high performance concrete (HI-UHPC) with 28-day resistivity of greater than 3 kΩ/m and compressive strength of greater than 120 MPa was prepared for subway engineering. The parameter influences on the alternating current (AC) impedance performance of HI-UHPC were investigated by AC impedance spectroscopy. An equivalent circuit model suitable for HI-UHPC was proposed. The results show that the compressive strength of HI-UHPC can be improved by adding steel fiber and PVA emulsion powder. The high-frequency arc of ordinary cement-based materials appears at 10-h hydration, while that of HI-UHPC appears at 1-h hydration. The addition of steel fiber can form the conductive channels via overlapping steel fiber in HI-UHPC, increase a possibility of free electron transfer and reduce the volume resistance of the matrix. When PVA emulsion powder is added into HI-UHPC, the interface between the matrix and PVA emulsion powder film is formed, changing the pore structure, reducing the effective conductive path in the interior of HI-UHPC, and ultimately improving the impedance performance. The equivalent circuit model of HI-UHPC consists of connected conductive path, disconnected conductive path and insulated path as well. As the ages increase, the hydration products and polymer films gradually form, the free water in the matrix consumes, and the pore structure becomes dense, leading to the blocking of the carrier transport channels in the pores. The resistance of connected conductive channel and the resistance of unconnected conductive channel increase, while the capacitance of unconnected conductive channel and the capacitance of insulating conductive matrix decrease.

    Nov. 23, 2022
  • Vol. 50 Issue 2 492 (2022)
  • RONG Hui, CHEN Xiaojie, LIU De-E, ZHANG Ying, ZHANG Lei, FENG Yang, and LIU Zhihua

    With the promotion of the national blue ocean strategy, concrete is widely used in various marine engineering facilities (i.e., cross-sea bridges, sub-sea tunnels, harbour terminals, etc.). However, concrete suffers from physical, chemical and biological synergistic effects during its service, eventually leading to its deterioration. The mechanism of concrete deterioration caused by physical and chemical effects is well known. In the marine environment, however, the mechanism of concrete deterioration caused by organisms, especially macro organisms (i.e., plant type and animal type) is still unclear. Therefore, this review represented recent work on the corrosion mechanism of macroscopic organisms in marine concrete, some factors affecting the attachment behavior of macroscopic organisms, and the related protective characterizations as well for more reasonable, efficient, economic and environmentally friendly corrosion management of marine concrete used.

    Nov. 23, 2022
  • Vol. 50 Issue 2 503 (2022)
  • WANG Penggang, MO Rui, SUI Xiaomeng, TIAN Li, XU Jun, and JIN Zuquan

    Reinforced concrete structure in a chloride and sulfate coupling environment is vulnerable to be deteriorated due to the combined chloride-sulfate attack. Based on the attack mechanism of chloride and sulfate, this review analyzed the diffusion-binding process of chloride and sulfate ions before and after damage of concrete caused by sulfate attack. Based on the classical diffusion-reaction model and the chemo-damage-transport theoretical framework, the effects of ion activity, temperature, microstructure change and calcium leaching on the chemo-damage-transport system were represented. The coupled transport thermodynamic model of chloride ions and sulfate ions was introduced from the perspective of thermodynamics. In addition, some existing problems in the current research were also prospected.

    Nov. 23, 2022
  • Vol. 50 Issue 2 512 (2022)
  • YANG Zhengxian, LI Kang, ZHANG Yong, WANG Yan, and NIU Ditao

    The use of natural plant fibers to reinforce cement-based materials has attracted recent attention. Compared with synthetic fibers, natural plant fibers have many advantages, such as green environmental protection, light weight, low cost, renewable, etc., and are widely used in many fields. However, natural plant fibers cannot be directly applied to cement-based materials since they are easy to absorb water and swell and have a poor compatibility with cement matrix. Therefore, a proper pretreatment of natural plant fibers is needed to improve the adverse effects of natural plant fibers on the properties of cement-based composites. This review represented , recent work on the development of different pretreatment methods for natural plant fibers (i.e., water treatment, coating treatment, steam treatment, alkali treatment, acid treatment, silane coupling agent treatment and mixing treatment) based on the structure and material composition of natural plant fibers, as well as the effect of the pretreatment method on the properties of natural plant fiber reinforced cement-based composites.

    Nov. 23, 2022
  • Vol. 50 Issue 2 522 (2022)
  • LI Kai, ZHAO Wen, and SHI Caijun

    Cement hydration is a complex chemical and physical reaction process, which directly determines the microstructure and macro-property of hardened cement paste. Since conventional experimental methods are in general time-consuming, laborious and expensive, computer simulation thus becomes popular in understanding the mechanism of cement hydration and microstructure development in recent years. In this review, existing hydration models were introduced, and their advantages and drawbacks were described. Recent work on the cement hydration simulation were summarized, in which the emphasis is on the hydration of non-spherical cement particles and nano-scale simulation of calcium silicate hydrate. Based on the practical application of relevant models, the effect of mineral admixtures on the hydration process and microstructure of cement paste was discussed. The properties of cement-based materials (i.e., agent transport, chloride diffusion and microcrack propagation) were represented as well.

    Nov. 23, 2022
  • Vol. 50 Issue 2 533 (2022)
  • ZHANG Peng, GUO Deyang, BAO Jiuwen, KOU Hailei, XUE Shanbin, and ZHAO Tiejun

    Concrete materials in service are often affected by the coupling action of mechanical and environmental factors. Microcracks inside concrete occur due to the complex stress induced by the combined action of moisture, heat, chemistry and mechanics, promoting the ingress process of water and aggressive ions and further accelerating the durability degradation process of reinforced concrete structures. In order to delay the deterioration of mechanical properties and durability of concrete under severe environments, the self-healing mechanisms of crack within concrete crack through the microbial mineralization technology were investigated. Based on the mechanism of self-healing concrete and regarded the realization mode of microbial healing and its influence on durability of concrete, recent studies on the microbial self-healing of cement-based materials under mineralization were summarized. Finally, the application of different types of microbial-induced calcium carbonate precipitation technology in cement-based materials was represented.

    Nov. 23, 2022
  • Vol. 50 Issue 2 544 (2022)
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