资源类型

期刊论文 1919

会议视频 65

会议信息 2

会议专题 1

年份

2024 4

2023 161

2022 205

2021 184

2020 172

2019 146

2018 113

2017 123

2016 85

2015 101

2014 60

2013 60

2012 43

2011 53

2010 55

2009 61

2008 61

2007 72

2006 49

2005 35

展开 ︾

关键词

机器学习 10

遗传算法 10

优化 7

医学 7

神经网络 7

能源 7

高分子材料 7

可持续发展 5

碳中和 5

预测 5

固体氧化物燃料电池 4

多目标优化 4

智能制造 4

材料 4

材料设计 4

目标识别 4

4D打印 3

BP神经网络 3

COVID-19 3

展开 ︾

检索范围：

排序： 展示方式：

Autogenous healing mechanism of cement-based materials

《结构与土木工程前沿（英文）》   页码 948-963 doi: 10.1007/s11709-023-0960-3

摘要： Autogenous self-healing is the innate and fundamental repair capability of cement-based materials for healing cracks. Many researchers have investigated factors that influence autogenous healing. However, systematic research on the autogenous healing mechanism of cement-based materials is lacking. The healing process mainly involves a chemical process, including further hydration of unhydrated cement and carbonation of calcium oxide and calcium hydroxide. Hence, the autogenous healing process is influenced by the material constituents of the cement composite and the ambient environment. In this study, different factors influencing the healing process of cement-based materials were investigated. Scanning electron microscopy and optical microscopy were used to examine the autogenous healing mechanism, and the maximum healing capacity was assessed. Furthermore, detailed theoretical analysis and quantitative detection of autogenous healing were conducted. This study provides a valuable reference for developing an improved healing technique for cement-based composites.

关键词： autogenous healing     cement-based materials     healing mechanism     aggregation effect    

HTML PDF 收藏

Microbial self-healing of cracks in cement-based materials and its influencing factors

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0986-6

摘要： Cement-based materials are brittle and crack easily under natural conditions. Cracks can reduce service life because the transport of harmful substances can cause corrosion damage to the structures. This review discusses the feasibility of using microbial self-healing agents for crack healing. Tubular and spherical carriers can be used to load microbial self-healing agents and protect microbes, which prolongs the self-healing time. The area self-healing ratio, permeability, mechanical strength, precipitation depth method, numerical modeling, and ultrasonic method can be employed to identify the self-healing effect of cracks. Moreover, the self-healing mechanism is systematically analyzed. The results showed that microbial self-healing agents can repair cracks in cement-based materials in underground projects and dam gates. The difficulties and future development of self-healing cracks were analyzed. A microbial self-healing agent was embedded in the cement-based material, which automatically repaired the developing cracks. With the development of intelligent building materials, self-healing cracks have become the focus of attention.

关键词： cement-based materials     cracks     microbial self-healing agent     mechanism     intelligent building materials    

HTML PDF 收藏

Effect of size on biaxial flexural strength for cement-based materials by using a triangular plate method

Hakan T TURKER

《结构与土木工程前沿（英文）》 2022年 第16卷 第8期   页码 1017-1028 doi: 10.1007/s11709-022-0871-8

摘要： The effect of size on the biaxial flexural strength (BFS) of Portland cement mortar was investigated by using the recently proposed triangular plate method (TPM). An experimental program was conceived to study the size effect by keeping a constant water-cement ratio of 0.485, cement-sand ratio of 1:2.75, and using unreinforced triangular mortar plates of five different thicknesses and seven different side lengths. The BFS of the produced specimens was tested, and variations of BFS depending on specimen thickness and side length were determined. The results indicated that increases in triangular plate specimen side length and specimen thickness led to a decrease in the BFS of Portland cement mortar. The effect of specimen length increase on BFS was more significant than on the effect of the specimen thickness. The variations in specimens’ thickness indicated a deterministic Type I size effect, while the variations in specimens’ length showed an energetic-statistical Type I size effect.

关键词： testing     apparatus & methods     plain concrete     tensile properties     biaxial flexural strength     triangular plate method    

HTML PDF 收藏

Appraising the potential of calcium sulfoaluminate cement-based grouts in simulated permafrost environments

《结构与土木工程前沿（英文）》 2023年 第17卷 第5期   页码 722-731 doi: 10.1007/s11709-023-0950-5

摘要： The aim of this study is to appraise the potential of calcium sulfoaluminate (CSA) cement-based grouts in simulated permafrost environments. The hydration and performance of CSA cement-based grouts cured in cold environments (10, 0, and −10 °C) are investigated using a combination of tests, including temperature recording, X-ray diffraction (XRD) tests, thermogravimetric analysis (TGA), and unconfined compressive strength (UCS) tests. The recorded temperature shows a rapid increase in temperature at the early stage in all the samples. Meanwhile, results of the TGA and XRD tests show the generation of a significant quantity of hydration products, which indicates the rapid hydration of CSA cement-based grouts at the early stage at low temperatures. Consequently, the CSA cement-based grouts exhibit remarkably high early strength. The UCS values of the samples cured for 2 h at −10, 0, and 10 °C are 6.5, 12.0, and 12.3 MPa, respectively. The UCS of the grouts cured at −10, 0, and 10 °C increases continuously with age and ultimately reached 14.9, 19.0, and 30.6 MPa at 28 d, respectively. The findings show that the strength of grouts fabricated using CSA cement can develop rapidly in cold environments, thus rendering them promising for permafrost applications.

关键词： permafrost     low temperatures     calcium sulfoaluminate cement-based grouts     hydration reaction     compressive strength    

HTML PDF 收藏

Experimental study on mechanical properties of a novel micro-steel fiber reinforced magnesium phosphate cement-based

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 1047-1057 doi: 10.1007/s11709-021-0755-3

摘要： Magnesium phosphate cement (MPC) received increased attention in recent years, but MPC-based concrete is rarely reported. The micro-steel fibers (MSF) were added to MPC-based concrete to enhance its ductility due to the high brittleness in tensile and flexural strength properties of MPC. This paper investigates the effect of MSF volume fraction on the mechanical properties of a new pattern of MPC-based concrete. The temperature development curve, fluidity, cubic compressive strength, modulus of elastic, axial compressive strength, and four-point flexural strength were experimentally studied with 192 specimens, and a scanning electron microscopy (SEM) test was carried out after the specimens were failed. Based on the test results, the correlations between the cubic compressive strength and curing age, the axial and cubic compressive strength of MPC-based concrete were proposed. The results showed that with the increase of MSF volume fraction, the fluidity of fresh MPC-based concrete decreased gradually. MSF had no apparent influence on the compressive strength, while it enhanced the four-point flexural strength of MPC-based concrete. The four-point flexural strength of specimens with MSF volume fraction from 0.25% to 0.75% were 12.3%, 21.1%, 24.6% higher than that of the specimens without MSF, respectively.

关键词： magnesium phosphate cement-based concrete     micro-steel fibers     four-point flexural strength     compressive strength    

HTML PDF 收藏

Characterization of 3D microstructure, thermal conductivity, and heat flow of cement-based foam using

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 643-651 doi: 10.1007/s11709-021-0709-9

摘要： This study presents the results of the 3D microstructure, thermal conductivity, and heat flow in cement-based foams and examines their changes with a range of densities. Images were captured using X-ray micro computed tomography (micro-CT) imaging technique on cement-based foam samples prepared with densities of 400, 600, and 800 kg/m3. These images were later simulated and quantified using 3D data visualization and analysis software. Based on the analysis, the pore volume of 11000 µm3 was determined across the three densities, leading to optimal results. However, distinct pore diameters of 15 µm for 800 kg/m3, and 20 µm for 600 and 400 kg/m3 were found to be optimum. Most of the pores were spherical, with only 10% appearing elongated or fractured. In addition, a difference of 15% was observed between the 2D and 3D porosity results. Moreover, a difference of 5% was noticed between the experimentally measured thermal conductivity and the numerically predicted value and this variation was constant across the three cast densities. The 3D model showed that heat flows through the cement paste solids and with an increase in porosity this flow reduces.

关键词： 3D pore volume distribution     X-ray tomography     3D shape factor     heat flow    

HTML PDF 收藏

高性能多功能水泥基复合材料 Article

Victor C. Li

《工程（英文）》 2019年 第5卷 第2期   页码 250-260 doi: 10.1016/j.eng.2018.11.031

摘要：

混凝土是一种不断发展的材料，甚至高性能混凝土的定义也正随着时间的推移而发生变化。本文所说的混凝土材料的高性能特性是指那些直接影响我们生活质量的民用基础设施的理想耐久性、回弹性和可持续性的特性。这些特性包括拉伸延展性、自体裂缝宽度控制和材料的“绿色”环保性。此外，智能功能应旨在通过响应结构周围环境的变化来提高基础设施的耐久性、回弹性和可持续性以实现其理想功能，从而使材料的行为方式更类似于某些生物材料。本文基于工程水泥基复合材料（ECC）的最新研究进展，提出可以设计出具有高性能兼智能多功能性的混凝土材料，并且其具有满足 21 世纪民用基础设施预期需求的潜力。本文重点介绍了 ECC 的相关特性以及未来研究的方向。

关键词： 高性能混凝土     多功能     智能     水泥基复合材料     耐久性     回弹性     可持续性     基础设施    

HTML PDF 收藏

水泥基材料及其性能的分子模拟研究 Review

Ashraf A. Bahraq, Mohammed A. Al-Osta, Omar S. Baghabra Al-Amoudi, I.B. Obot,Mohammed Maslehuddin, Habib-ur-Rehman Ahmed, Tawfik A. Saleh

《工程（英文）》 2022年 第15卷 第8期   页码 165-178 doi: 10.1016/j.eng.2021.06.023

摘要：

Hydrated cement is one of the complex composite systems due to the presence of multi-scale phases with varying morphologies. Calcium silicate hydrate (C–S–H), which is the principal binder phase in the hydrated cement, is responsible for the stiffness, strength, and durability of Portland cement concrete. To understand the mechanical and durability behavior of concrete, it is important to investigate the interactions of hydrated cement phases with other materials at the nanoscale. In this regard, the molecular simulation of cement-based materials is an effective approach to study the properties and interactions of the cement system at the fundamental scale. Recently, many studies have been published regarding atomistic simulations to investigate the cement phases to define/explain the microscopic physical and chemical properties, thereby improving the macroscopic performance of hardened binders. The research in molecular simulation of cementitious systems involves researchers with multidisciplinary backgrounds, mainly in two areas: ① cement chemistry, where the hydration reactions govern most of the chemical and physical properties at the atomic scale; and ② computational materials science and engineering, where the bottom-up approach is required. The latter approach is still in its infancy, and as such, a study of the prevailing knowledge is useful, namely through an exhaustive literature review. This state-of-the-art report provides a comprehensive survey on studies that were conducted in this area and cites the important findings.

关键词： Atomistic simulation     Molecular dynamics     Cement phases     Hydration products     Nanoengineering    

HTML PDF 收藏

Cement-based solidification/stabilization of contaminated soils by nitrobenzene

Jianguo LIU, Xiaoqin NIE, Xianwei ZENG, Zhaoji SU

《环境科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 437-443 doi: 10.1007/s11783-012-0406-y

摘要： The cement-based solidification/stabilization (S/S) of nitrobenzene (NB) contaminated soils, with cement and lime as binders, sodium silicate solution and powder activated carbon (PAC) as additives, was optimized through an orthogonal experiment, and S/S efficiency was estimated by both leaching test and volatilization measurement. The leaching test results showed that the factors affecting S/S efficiency were NB concentration, cement-to-lime ratio and binder-to-soils ratio, in sequence. With increasing curing time, the leaching concentration of NB between different levels of the same factor in the orthogonal experiment decreased, and less than 9% NB leached out from the 28 d cured samples. The volatilization measurement results indicated that 0.5‰ of NB was volatilized during the mixing and curing processes for the samples without PAC in the 28 d cycle, whereas adding 2 wt% and 5 wt% PAC, with respect to the weight of contaminated soils, could reduce NB volatilization to half of its original values either during the mixing or curing process. The optimizing formula, that is, contaminated soils (dry weight):cement:lime= 100:25:25, with 5 wt% additional sodium silicate and 2 wt% additional PAC, was applied to the engineering application of NB contaminated soils. Both the leaching test results of the product and the ambient air quality monitoring results met related regulations during the treating process.

关键词： solidification/stabilization     nitrobenzene     contaminated soils     powder activated carbon    

HTML PDF 收藏

Silicon carbide waste as a source of mixture materials for cement mortar

Zhengwu Jiang, Qiang Ren, Haoxin Li, Qing Chen

《环境科学与工程前沿（英文）》 2017年 第11卷 第5期 doi: 10.1007/s11783-017-0974-y

摘要： This paper presents an investigation of the feasibility of recycling silicon carbide waste (SCW) as a source of mixture materials in the production of cement mortar. Mortars with SCW were prepared by replacing different amounts of cement with SCW, and the properties of the resulting mortars, such as the fluidity, strength and shrinkage, were studied in this work. Thermogravimetry-differential scanning calorimetry and scanning electron microscopy were employed to understand the reasons for the property changes of the mortars. The results indicate that SCW decreases the initial and 1-h fluidity of fresh mortar but improves the loss of fluidity. The mortar with SCW exhibits a lower strength at 3 d and 7 d but a higher strength at 28 d and 56 d compared to the control. The shrinkage rate of cement mortar with SCW shows an obvious decrease as the replacement ratio increases. In addition, the content of calcium hydroxide in hardened paste also shows that SCW has some impact on the hydration of the cement-SCW system. The microstructures of the hardened paste also show evidence for a later strength change of mortar containing SCW. This work provides a strategic reference for possibly applying SCW as a mixture material in the production of cement mortar.

关键词： Silicon carbide waste     Cement mortar     Fluidity     Strength     Shrinkage    

HTML PDF 收藏

Adsorption properties of polycarboxylate ether-based superplasticizer on cement particles and their resultant

Jinyoung YOON; Byoung Il CHOI; Jae Hong KIM

《结构与土木工程前沿（英文）》 2022年 第16卷 第4期   页码 506-514 doi: 10.1007/s11709-022-0813-5

摘要： The cement dispersion performance of a polycarboxylate (PCE)-based superplasticizer is highly related to their adsorption behaviors as a function of time. This study evaluated effects of PCEs on rheological properties of cementitious materials. First, characteristics of PCEs were characterized via permeation chromatography (GPC) and Fourier-transform infrared spectrometry (FT-IR). The adsorption behavior of single and blended PCEs on cementitious composites was identified using total organic carbon analyzer (TOC). Based on the measurement of PCE adsorption, the changes of rheological properties of cementitious materials as well as the number of dispersed cement particles were characterized using a rheometer and laser spectroscopy, respectively. The experimental results support the systematic mechanism of PCE adsorption, cement dispersion, and the decrease in viscosity of cementitious materials.

关键词： adsorption     polycarboxylate     superplasticizer     rheology     dispersion    

HTML PDF 收藏

Extending blending proportions of ordinary Portland cement and calcium sulfoaluminate cement blends:

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1249-1260 doi: 10.1007/s11709-021-0770-4

摘要： This study extended blending proportion range of ordinary Portland cement (OPC) and calcium sulfoaluminate (CSA) cement blends, and investigated effects of proportions on setting time, workability, and strength development of OPC-CSA blend-based mixtures. Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were conducted to help understand the performance of OPC-CSA blend-based mixtures. The setting time of the OPC-CSA blends was extended, and the workability was improved with increase of OPC content. Although the early-age strength decreased with increase of OPC content, the strength development was still very fast when the OPC content was lower than 60% due to the rapid formation and accumulation of ettringite. At 2 h, the OPC-CSA blend-based mortars with OPC contents of 0%, 20%, 40%, and 60% achieved the unconfined compressive strength (UCS) of 17.5, 13.9, 9.6, and 5.0 MPa, respectively. The OPC content had a negligible influence on long-term strength. At 90 d, the average UCS of the OPC-CSA blend-based mortars was 39.2 ± 1.7 MPa.

关键词： calcium sulfoaluminate cement     cement blends     hydration reaction     setting     workability     compressive strength    

HTML PDF 收藏

Effect of surgical factors on the augmentation of cement-injectable cannulated pedicle screw fixationby a novel calcium phosphate-based nanocomposite

Haolin Sun, Chun Liu, Shunlun Chen, Yanjie Bai, Huilin Yang, Chunde Li, Lei Yang

《医学前沿（英文）》 2019年 第13卷 第5期   页码 590-601 doi: 10.1007/s11684-019-0710-z

摘要： Bone cement-augmented pedicle screw system demonstrates great efficacy in spinal disease treatments. However, the intrinsic drawbacks associated with clinically used polymethylmethacrylate (PMMA) cement demands for new bone cement formulations. On the basis of our previous studies, a novel injectable and biodegradable calcium phosphate-based nanocomposite (CPN) for the augmentation of pedicle screw fixation was systematically evaluated for its surgical feasibility and biomechanical performance by simulated and animal osteoporotic bone models, and the results were compared with those of clinical PMMA cement. ASTM-standard solid foam and open-cell foam models and decalcified sheep vertebra models were employed to evaluate the augmentation effects of CPN on bone tissue and on the cement-injected cannulated pedicle screws (CICPs) placed in osteoporotic bone. Surgical factors in CICPs application, such as injection force, tapping technique, screw diameter, and pedicle screw loosening scenarios, were studied in comparison with those in PMMA. When directly injected to the solid foam model, CPN revealed an identical augmentation effect to that of PMMA, as shown by the similar compressive strengths (0.73±0.04 MPa for CPN group vs. 0.79±0.02 MPa for PMMA group). The average injection force of CPN at approximately 40–50 N was higher than that of PMMA at approximately 20 N. Although both values are acceptable to surgeons, CPN revealed a more consistent injection force pattern than did PMMA. The dispersing and anti-pullout ability of CPN were not affected by the surgical factors of tapping technique and screw diameter. The axial pullout strength of CPN evaluated by the decalcified sheep vertebra model revealed a similar augmentation level as that of PMMA (1351.6±324.2 N for CPN vs. 1459.7±304.4 N for PMMA). The promising results of CPN clearly suggest its potential for replacing PMMA in CICPs augmentation application and the benefits of further study and development for clinical uses.

关键词： bone cement     pedicle screw     degenerative spinal diseases     calcium phosphate     injectable    

HTML PDF 收藏

Reliability-based settlement analysis of embankments over soft soils reinforced with T-shaped deep cement

Chana PHUTTHANANON; Pornkasem JONGPRADIST; Daniel DIAS; Xiangfeng GUO; Pitthaya JAMSAWANG; Julien BAROTH

《结构与土木工程前沿（英文）》 2022年 第16卷 第5期   页码 638-656 doi: 10.1007/s11709-022-0825-1

摘要： This paper presents a reliability-based settlement analysis of T-shaped deep cement mixing (TDM) pile-supported embankments over soft soils. The uncertainties of the mechanical properties of the in-situ soil, pile, and embankment, and the effect of the pile shape are considered simultaneously. The analyses are performed using Monte Carlo Simulations in combination with an adaptive Kriging (using adaptive sampling algorithm). Individual and system failure probabilities, in terms of the differential and maximum settlements (serviceability limit state (SLS) requirements), are considered. The reliability results for the embankments supported by TDM piles, with various shapes, are compared and discussed together with the results for conventional deep cement mixing pile-supported embankments with equivalent pile volumes. The influences of the inherent variabilities in the material properties (mean and coefficient of variation values) on the reliability of the piled embankments, are also investigated. This study shows that large TDM piles, particularly those with a shape factor of greater than 3, can enhance the reliability of the embankment in terms of SLS requirements, and even avoid unacceptable reliability levels caused by variability in the material properties.

关键词： T-shaped deep cement mixing piles     piled embankments     settlement     reliability analysis     soil uncertainties    

HTML PDF 收藏

Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration

Jun WU,Xuemei LIU

《结构与土木工程前沿（英文）》 2015年 第9卷 第3期   页码 323-340 doi: 10.1007/s11709-015-0301-2

摘要： This paper presents a combined experimental and numerical study on the damage and performance of a soft-hard-soft (SHS) multi-layer cement based composite subjected to blast loading which can be used for protective structures and infrastructures to resist extreme loadings, and the composite consists of three layers of construction materials including asphalt concrete (AC) on the top, high strength concrete (HSC) in the middle, and engineered cementitious composites (ECC) at the bottom. To better characterize the material properties under dynamic loading, interface properties of the composite were investigated through direct shear test and also used to validate the interface model. Strain rate effects of the asphalt concrete were also studied and both compressive and tensile dynamic increase factor (DIF) curves were improved based on split Hopkinson pressure bar (SHPB) test. A full-scale field blast test investigated the blast behavior of the composite materials. The numerical model was established by taking into account the strain rate effect of all concrete materials. Furthermore, the interface properties were also considered into the model. The numerical simulation using nonlinear finite element software LS-DYNA agrees closely with the experimental data. Both the numerical and field blast test indicated that the SHS composite exhibited high resistance against blast loading.

关键词： high strength concrete (SHS)     engineered cementitious composite     interface     blast test     strain rate effect    

HTML PDF 收藏

标题 作者 时间 类型 操作

Autogenous healing mechanism of cement-based materials

期刊论文

Microbial self-healing of cracks in cement-based materials and its influencing factors

期刊论文

Effect of size on biaxial flexural strength for cement-based materials by using a triangular plate method

Hakan T TURKER

期刊论文

Appraising the potential of calcium sulfoaluminate cement-based grouts in simulated permafrost environments

期刊论文

Experimental study on mechanical properties of a novel micro-steel fiber reinforced magnesium phosphate cement-based

期刊论文

Characterization of 3D microstructure, thermal conductivity, and heat flow of cement-based foam using

期刊论文

高性能多功能水泥基复合材料

Victor C. Li

期刊论文

水泥基材料及其性能的分子模拟研究

Ashraf A. Bahraq, Mohammed A. Al-Osta, Omar S. Baghabra Al-Amoudi, I.B. Obot,Mohammed Maslehuddin, Habib-ur-Rehman Ahmed, Tawfik A. Saleh

期刊论文

Cement-based solidification/stabilization of contaminated soils by nitrobenzene

Jianguo LIU, Xiaoqin NIE, Xianwei ZENG, Zhaoji SU

期刊论文

Silicon carbide waste as a source of mixture materials for cement mortar

Zhengwu Jiang, Qiang Ren, Haoxin Li, Qing Chen

期刊论文

Adsorption properties of polycarboxylate ether-based superplasticizer on cement particles and their resultant

Jinyoung YOON; Byoung Il CHOI; Jae Hong KIM

期刊论文

Extending blending proportions of ordinary Portland cement and calcium sulfoaluminate cement blends:

期刊论文

Effect of surgical factors on the augmentation of cement-injectable cannulated pedicle screw fixationby a novel calcium phosphate-based nanocomposite

Haolin Sun, Chun Liu, Shunlun Chen, Yanjie Bai, Huilin Yang, Chunde Li, Lei Yang

期刊论文

Reliability-based settlement analysis of embankments over soft soils reinforced with T-shaped deep cement

Chana PHUTTHANANON; Pornkasem JONGPRADIST; Daniel DIAS; Xiangfeng GUO; Pitthaya JAMSAWANG; Julien BAROTH

期刊论文

Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration

Jun WU,Xuemei LIU

期刊论文