检索结果-南通市图书馆

Carbon uptake by cement in China:Estimation and contribution to carbon neutrality goals

Science China Earth Sciences 2024年第6期67卷 2056-2067页

作者： Mingjing MA Zi HUANG Jiaoyue WANG Le NIU Wenfeng ZHANG Xiaowei XU Fengming XI Zhu LIU Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Department of Earth System Science Tsinghua UniversityBeijing 100084China Department of Engineering Science University of OxfordOxfordOX13UK

cement is a widely used construction material globally.Its manufacturing contributes to anthropogenic CO_(2)emissions significantly.However,its alkaline compounds can absorb CO_(2)from the surrounding environment and engage in a carbonation reaction,thereby functioning as a carbon sink.As a major cement producer and consumer,China has an important responsibility to rigorously investigate and accurately account for cement carbon uptake.This study presents a comprehensive analytical model of cement carbon uptake from China,revealing a substantial increase in carbon uptake from 1930 to 2021,peaking at 426.77 Mt CO_(2)(95% Confidence Interval:317.67-874.33 Mt CO_(2))in 2021.The uptake accounts for 8.10% to 45.40% of China’s annual land sink and 2.51% to 4.54% of the global land sink.The cumulative carbon uptake by cement is approximately 7.06 Gt CO_(2)(95%CI:5.22–9.44 Gt CO_(2))during this period,offsetting 50.7% of the total emissions(13.91 Gt CO_(2),95%CI:12.44–17.00 Gt CO_(2))from the cement industry.Notably,cement mortar contributed to most absorption(65.64%).From a life cycle perspective,the service stage of cement materials is the period where the largest CO_(2)sink is formed,accounting for 90.03% of the total.Therefore,the potential for carbon sequestration in cement materials and their waste is enormous.Additionally,the model improves the accuracy of cement carbon accounting,supporting both China and global carbon neutrality assessments.Thus,it is crucial for China to achieve its carbon neutrality goals sooner by prioritizing the environmental benefits of cement materials and wastes,and accelerating the development and commercialization of CO_(2)sequestration technologies for cement and its by-products.

关键词： cement Carbon uptake Life cycle assessment Carbon emission reduction Carbon neutrality

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A novel and promising engineering application of carbon dots:Enhancing the chloride binding performance of cement

引用

Chinese Chemical Letters 2024年第6期35卷 409-416页

作者： Wu-Jian Long Yang Yu Chuang He Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering Key Lab of Coastal Urban Resilient InfrastructureMOECollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Corrosion of reinforcement induced by chloride invasion is extensively considered as the dominating deterioration mechanism of reinforced concrete(RC)structures,leading to serious safety hazards and tremendous economic losses.However,it still lacks well dispersive and cost-efficient nanomaterials to improve the anti-chloride-corrosion ability of RC structures.Herein,specific carbon dots(CDs)with high dispersity and low cost are deliberately designed,successfully prepared by hydrothermal processing,and then firstly applied to immensely enhance chloride binding performance of cement,thereby contributing to suppressing the corrosion of reinforcement.Specifically,the tailored CDs are composed of the carbon core with highly crystalline sp^(2)C structures and oxygen-containing groups connecting on the carbon core;The typical equilibrium test confirms that with respect to that of the blank cement paste,the chloride binding capacity of cement paste involving 0.2 wt%(by weight of cement)CDs is increased by 109% after 14-day exposure to 3 mol/L Na Cl solution;according to comprehensive analyses of phase compositions,the chloride binding mechanism of CDs-modified cement is rationally attributed to the fact that the incorporation of CDs advances the formation of calcium silicate hydrate(C-S-H)gels and Friedel's salt(Fs),thus enormously enhancing the physically adsorbed and chemically bound chloride ions of cement pastes.This work not only firstly provides a novel high-dispersity and low-cost nanomaterial toward the durability enhancement of RC structures,but also broadens the application of CDs in the field of engineering,conducing to stimulating their industrialization development.

关键词： Carbon dots Chloride binding cement Chloride binding mechanism Friedel’s salt

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

cement and Lime Stabilization Effect on the Evolutivity of an Expansive Overconsolidated Clay

引用

Journal of Civil Engineering and Architecture 2024年第3期18卷 134-140页

作者： Mohamed Khemissa Geomaterials Development Laboratory Mohamed Boudiaf UniversityM'sila 28000Algeria

This paper presents and analyzes the results of a series of compaction,fragmentability and damage tests performed on an expansive overconsolidated clay treated with cement and lime.This clay was obtained from the urban site of Sidi-Hadjrès city(wilaya of M'sila,Algeria),where significant damages frequently appears in the road infrastructures,roadway systems and light structures.Tests results obtained show that the geotechnical parameters values deduced from these tests are concordant and confirm the evolutivity of this natural clay treated with composed Portland cement or extinct lime and compacted under optimum Proctor conditions.

关键词： Expansive clay evolutivity treatment cement lime fragmentability coefficient damage coefficient

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bio-PCM Panels Composed of Renewable Materials Interact with Solar Heating Systems for Building Thermal Insulation

引用

Journal of Renewable Materials 2024年第4期12卷 771-798页

作者： Yosr Laatiri Habib Sammouda Fadhel Aloulou Laboratory of Energy and Materials:LabEM-LR11ES34 University of SousseHammam SousseTunisia

This article aims to present the feasibility of storing thermal energy in buildings for solar water heating while maintaining the comfort environment for residential buildings.Our contribution is the creation of insulating composite panels made of bio-based phase change materials(bio-PCM is all from coconut oil),cement and renewable materials(treated wood fiber and organic clay).The inclusion of wood fibers improved the thermal properties;a simple 2%increase of wood fiber decreased the heat conductivity by approximately 23.42%.The issues of bio-PCM leakage in the cement mortar and a roughly 56.5%reduction in thermal conductivity with bio-PCM stability in composite panels can be resolved by treating wood fibers with an adjuvant by impregnating them in bio-PCM in the presence of the treated clay generated.Clay and wood fiber were treated with adjuvants that are both biological and environmentally acceptable,as confirmed by FTIR spectroscopy.The heat transfer bench(DIDATEK)showed a decrease in thermal conductivity.By using differential scanning calorimetric(DSC)analysis,the investigation of thermal stability and enthalpy during two heating cycles of pure bio-PCM and composite bio-PCM was validated.The novel renewable material was used to create composite panels for the trial prototype,which took the shape of a component attached to the solar heating system,33.57%less heat was lost,according to the heat transfer research.The outcomes demonstrated the possibility of replacing traditional electric water heating in residential buildings with solar water heating systems.

关键词： cement wood fiber PCM thermal conductivity thermal insulation solar energy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect and mechanism of nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive on compressive strength of calcium aluminate cement at high temperature

引用

Journal of Iron and Steel Research(International) 2022年第7期29卷 1063-1072页

作者： Qian Sun En-hui Wang Xin-mei Hou Zhi-jun He Tong-xiang Liang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Material and Metallurgy University of Science and Technology LiaoningAnshan 114501LiaoningChina School of Materials Science and Engineering Jiangxi University of Science and TechnologyGanzhou 341000JiangxiChina

Calcium aluminate cement(CAC)is widely used as a binder for refractory materials,and thus the improvement in compressive strength is of vital importance for CAC applied at high temperature.For this purpose,nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive with a ratio of 0.5–1.5 mass%was added with the water-cement ratio to be 0.4.X-ray diffraction and isothermal calorimetry analysis demonstrate that nano-Ca_(10)(PO_(4))_(6)(OH)_(2)additive can shorten the hydration process and promote the formation of main hydrates of CaAl2O4·10H2O(CAH10)and Ca2Al2O5·8H2O(C2AH8).In addition,scanning electron microscopy results suggest that nano-Ca_(10)(PO_(4))_(6)(OH)_(2)can protect CAH10 and C2AH8 from being destroyed during the calcination,guaranteeing that these thin lamellar crystals are intertwined to form the denser microstructure.Benefited from above effects,nano-Ca_(10)(PO_(4))_(6)(OH)_(2)can obviously improve the compressive strength of the CAC mortar samples cured for 7 d after calcination at 1100°C,while the improving effect is dependent upon its contents.Especially,compared with the one without the additive,the compressive strength of the sample with 1.0%nano-Ca_(10)(PO_(4))_(6)(OH)_(2)is increased by 14%.

关键词： Nano-Ca_(10)(PO_(4))_(6)(OH)_(2) cement Calcination Microstructure Compressive strength

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Coal-Biomass Preheating Combustion Characteristics in cement Precalciner.Part 1:Preheating of Coal/Biomass

引用

Journal of Thermal Science 2023年第5期32卷 1868-1877页

作者： LI Pengpeng REN Qiangqiang HAN Shaobo ZHANG Chi LYU Qinggang School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing 102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The co-combustion of biomass and coal can positively impact the environment and reduce the cost of power generation.However,biomass fuels have many limitations.Circulating fluidized bed(CFB)preheating combustion is suitable for co-combusting coal and biomass because of better fuel adaptability.In the cement industry,fuel combustion and raw meal decomposition in precalciners affect cement quality and cause pollutant emissions.The preheating combustion method used in precalciners can improve combustion performance and reduce NO_(x)emissions.This study investigated the preheating characteristics of a coal-biomass mixed fuel in a cement precalciner.The effects of load,biomass type,and biomass proportion on the preheated fuel and the conditions of the CFB were investigated.The results indicated that a lower load reduces the combustible components in gaseous and solid preheated fuels.However,due to the gas volume remains constant under different loads,a lower load also increases temperature and intensifies the reaction.The carbon chain and microscopic structural activities of preheated fuels are considerably enhanced,facilitating their combustion in precalciners and reducing nitrogen oxides in rotary kilns.Furthermore,adding biomass can improve the reactivity of a fuel subjected to preheating.Thus,biomass fuels(e.g.,rice husks)exhibit high combustion efficiency,and thus high energy utilization.The present study achieved better pore structure and molecular activity using preheated fuel from a CFB preheater.In addition,the improvement of pore structure and molecular activity increases with the proportion of the biomass.

关键词： cement precalciner biomass circulating fluidized bed preheating combustion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hydration Characteristics and Mechanical Properties of cement-Based Materials Modified by Calcined Zeolite and Montmorillonite

引用

Journal of Renewable Materials 2023年第5期11卷 2191-2207页

作者： Lingling Qin Mengya Zhou Jiahao Yan Ping Duan Yingcan Zhu Wei Chen Zuhua Zhang Aiguo Wang Faculty of Materials Science and Chemistry Key Laboratory of Geological Survey and Evaluation of Ministry of EducationChina University of GeosciencesWuhan430074China Key Laboratory of Advanced Building Materials of Anhui Province Anhui Jianzhu UniversityHefei230022China Guangxi Key Laboratory of New Energy and Building Energy Saving Guilin University of TechnologyGuilin541004China Key Laboratory of Road Structure and Materials of Ministry of Transport Chang’an UniversityXi’an710064China Centre for Sustainable Agricultural Systems University of Southern QueenslandToowoombaQLD4350Australia State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan430070China Key Laboratory for Green&Advanced Civil EngineeringMaterials and Application Technology of Hunan Province College of Civil EngineeringHunan UniversityChangsha410082China

Montmorillonite and clinoptilolite zeolite were used as representative materials to prepare calcined clay-cement binary cementitious materials in order to study the effect of calcination treatment on the activation of clay minerals and the activity difference between layered and framed clays in this research.The influence of different calcined clay content(2%,4%,6%,8%,10%)on the fluidity,compressive strength,microstructure,phase change,and hydration heat of cement-based materials were analyzed.The calcined clay improves the fluidity of cement-based materials as compared with the uncalcined group.The addition of calcined montmorillonite(CMT)improves the development of mechanical strength,and the optimal compressive strength reaches 85 MPa at 28 days with 8%CMT.However,the activity of calcined clinoptilolite zeolite(CZL)is weak with few reaction sites,which slightly reduced the mechanical strength as compared to the blank sample.The addition of CMT changes the microscopic morphology of hydration products such as C-S-H and C-A-H,leading to the formation and transformation of ettringite in the early stage.It promotes the gradual polymerization of Si-O bonds into Si-O-Si bonds simultaneously,which accelerates the early hydration process.However,CZL acts mainly as a filling function in the cementitious system.In brief,CMT as an admixture can improve the mechanical properties of cement,but CZL has little effect.This work provides a guideline for the applications of calcined clay in cement,considering the influence of clay type on workability and mechanical strength.

关键词： Calcined clay cement montmorillonite clinoptilolite zeolite mechanical strength hydration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study on Triaxial Mechanical Properties and Micro Mechanism of Fly Ash Reinforced cement Calcareous Sand

引用

Journal of Renewable Materials 2022年第6期10卷 1693-1710页

作者： Ben Li Na Li Chulei Fang Jun Hu Rong Yu Longxin Shu Kai Yao Fang Zhang School of Civil Engineering Shaoxing UniversityShaoxing312000China College of Civil Engineering and Architecture Hainan UniversityHaikou570228China School of Qilu Transportation Shandong UniversityJinan250002China

In order to study the mechanical properties and micro-mechanism of industrial waste fly ash-reinforced cement calcareous sand(FCS),the triaxial unconsolidated undrained(UU)test and scanning electron microscope tests(SEM)were carried out on it.The results of UU test show that the peak stress and energy dissipation of the FCS sample first increase and then decrease with the increase in fly ash content.Fly ash enhances the cement calcareous sand by increasing both the cohesion and internal friction angle,and adding 10%content of fly ash gives the largest values.The SEM test results shows that the hydration products of cement and fly ash filled the pores and cracks on the surface of the calcareous sand,which increased the compactness and structure of the FCS samples.The porosity of cement calcareous sand can be reduced from 27.6%to 12.8%by adding 10%fly ash.A brittleness evaluation index based on energy dissipation is proposed to quantitatively characterize the brittleness of FCS samples.The results show that when the content of fly ash is 5%,the brittleness of FCS samples is the lowest.This study shows that the mechanical properties of cement calcareous sand can be effectively enhanced by adding the appropriate amount of fly ash.

关键词： Calcareous sand cement fly ash triaxial UU test SEM test

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Influence of Rice Husk Ash on Mechanical Properties of the Mortar and Concrete: A Critical Review

引用

Open Journal of Civil Engineering 2024年第1期14卷 65-81页

作者： Md Jahangir Alam Mithun Biswas Mohammad Biplab Mia Shahin Alam Md Mosabber Hossain College of Civil and Transportation Engineering Hohai University Nanjing China School of Civil Engineering Chang’an University Xi’an China

Increasing the population and infrastructure in both emerging and developed countries requires a considerable amount of cement, which significantly affects the environment. The primary materials of concrete (‘cement’) production emit a large quantity of CO2 into the environment. Also, the cost of conventional building materials like cement gives motivation to find geopolymer waste materials for concrete. To reduce harmful effects on the environment and cost of traditional concrete substance, alternative waste materials like rice husk ash (RHA), ground granulated blast-furnace (GGBS), fly ash (FA), and metakaolin (MK) can be used due to their pozzolanic behavior. RHA waste material with a high silica concentration obtained from burning rice husks can possibly be used as a supplementary cementitious material (SCM) in the manufacturing of concrete, and its strong pozzolanic properties can contribute to the strength and impermeability of concrete. This review paper highlights a summary of the positive effect of using RHA as a partial substitute for cement in building construction, as well as its optimal inclusion of enhanced mechanical properties like compressive strength, flexural strength, and split tensile strength of mortar and concrete.

关键词： cement Rice Husk Ash RHA Properties Mechanical Properties Carbon Di-oxide Emission and Greenhouse Gas

来源：

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Study on the Hydration and Physical Properties of cement by M18 Polycarboxylate Superplasticizer Modified Graphene Oxide

引用

Journal of Renewable Materials 2023年第2期11卷 625-641页

作者： Dalong Liao Dongxu Li Shun Zhou Xiaotao Zhang Ying Fang College of Materials Science and Engineering Nanjing Tech UniversityNanjing211816China

Graphene oxide(GO)as a new nano-enhancer in cement-based materials has gained wide attention.However,GO is easy to aggregate in alkaline cement mortar with poor dispersibility.This hinders its application in practical infrastructure construction.In this work,GO-M18 polycarboxylate compound superplasticizer(GM)were obtained by compounding the M18 polycarboxylate superplasticizer with GO solution at different mass ratios.The dispersion of GM in alkaline solution was systematically studied.The phases and functional groups of GM were characterized by XRD and FTIR.The effects of GM on the cement mortar hydration and the formation of microstructure were investigated by measuring the heat of hydration,MIP,TG/DSC,and SEM.The results show that the long-chain structure of the M18 polycarboxylate superplasticizer can increase the interlayer spacing of GO and weaken the force between GO sheets.The modified GO can be uniformly dispersed in the cement slurry.GM can accelerate the early hydration process of cement,which can increase the content of Ca(OH)2 and decrease the grain size.It can optimize the pore size distribution of cement-based materials,increase the density of harmless and less harmful pores,thereby improving mechanical properties.Such methods can transform traditional cement-based materials into stronger,more durable composites,which prolong the life of cement-based materials and reduce the amount of cement used for later maintenance.This provides an idea for achieving sustainability goals in civil engineering.

关键词： Modified graphene oxide cement polycarboxylate superplasticizer hydration properties me-chanical performance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：