Combined with DTG analysis, X-Ray diffraction analysis （XRD） and field emission scanning electron microscopy analysis （FSEM） affiliated with energy dispersive spectrometer analysis （EDS）, the early hydration and...Combined with DTG analysis, X-Ray diffraction analysis （XRD） and field emission scanning electron microscopy analysis （FSEM） affiliated with energy dispersive spectrometer analysis （EDS）, the early hydration and carbonation behavior of cement paste compacts incorporated with 30% of dolomite powder at low water to cement ratio （0.15） was investigated. The results showed that early carbonation curing was capable of developing rapid early strength. It is noted that the carbonation duration should be strictly controlled otherwise subsequent hydration might be hindered. Dolomite powder acted as nuclei of crystallization, resulting in acceleration of products formation and refinement of products crystal size. Therefore, as for cement-based material, it was found that early carbonation could reduce cement dosages to a large extent and promote rapid strength gain resulting from rapid formation of products, supplemental enhancement due to water release in the reaction of carbonation, and formation ofnanometer CaCO3 skeleton network at early age.展开更多
The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF...The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF)cement based composites at high relativehumidity.The MDF composites incorporated with vari-ouscross-coupling agents studied experimentally.The results show thatthe MDF composites modified with small amounts of cross-couplingagent had raised mechanical properties,but it is more important thatthe modified MDF composites had a significant increase in waterresistance compared to the original one.展开更多
1 Scope This standard specifies the term, definition, classification, labeling, technical requirements, test methods, inspection rules, packing, marking, transportation, storage, and quality certificate of spalling re...1 Scope This standard specifies the term, definition, classification, labeling, technical requirements, test methods, inspection rules, packing, marking, transportation, storage, and quality certificate of spalling resistant bauxite based bricks for cement kiln.展开更多
Radiative cooling has emerged as an attractive passive cooling technology in energy and thermal management fields due to its zero-energy consumption and pollution-free characteristics[[1],[2],[3]].An ideal radiative c...Radiative cooling has emerged as an attractive passive cooling technology in energy and thermal management fields due to its zero-energy consumption and pollution-free characteristics[[1],[2],[3]].An ideal radiative cooling material should simultaneously exhibit high solar reflectance to minimize solar heat absorption and high infrared emissivity in the“atmospheric window”band(8–13μm)to directly radiate heat to outer space(∼3 K),achieving passive cooling without energy input[[4],[5],[6]].Photonic structures(such as nano-multilayers,nano-pores,and photonic crystals)have been proven to simultaneously achieve high solar reflectance and broadband infrared emissivity[7,8].For instance,commercial“cooling paints”(such as BaSO4 and TiO2-based reflective paints)can reduce surface temperatures by several degrees and moderately decrease building cooling loads.展开更多
Cement-based materials are the foundation of modern buildings but suffer from intensive energy consumption.Utilizing cement-based materials for efficient energy storage is one of the most promising strategies for real...Cement-based materials are the foundation of modern buildings but suffer from intensive energy consumption.Utilizing cement-based materials for efficient energy storage is one of the most promising strategies for realizing zero-energy buildings.However,cement-based materials encounter challenges in achieving excellent electrochemical performance without compromising mechanical properties.Here,we introduce a biomimetic cement-based solid-state electrolyte(labeled as l-CPSSE)with artificially organized layered microstructures by proposing an in situ ice-templating strategy upon the cement hydration,in which the layered micropores are further filled with fast-ion-conducting hydrogels and serve as ion diffusion highways.With these merits,the obtained l-CPSSE not only presents marked specific bending and compressive strength(2.2 and 1.2 times that of traditional cement,respectively)but also exhibits excellent ionic conductivity(27.8 mS·cm^(-1)),overwhelming most previously reported cement-based and hydrogel-based electrolytes.As a proof-of-concept demonstration,we assemble the l-CPSSE electrolytes with cement-based electrodes to achieve all-cement-based solid-state energy storage devices,delivering an outstanding full-cell specific capacity of 72.2 mF·cm^(-2).More importantly,a 5×5 cm^(2) sized building model is successfully fabricated and operated by connecting 4 l-CPSSE-based full cells in series,showcasing its great potential in self-energy-storage buildings.This work provides a general methodology for preparing revolutionary cement-based electrolytes and may pave the way for achieving zero-carbon buildings.展开更多
Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched pris...Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.展开更多
Hydrated Cement Treated Crushed Rock Base （HCTCRB） is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. T...Hydrated Cement Treated Crushed Rock Base （HCTCRB） is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. These methods are not all-encompassing enough to adequately explain the behaviour of HCTCRB in the field. Recent developments in mechanistic approaches have proven more reliable in the design and analysis of pavement, making it possible to more effectively document the characteristics of HCTCRB. The aim of this study was to carry out laboratory testing to assess the mechanical characteristics of HCTCRB. Conventional triaxial tests and repeated load triaxial tests （RLT tests） were performed. Factors affecting the performance of HCTCRB, namely hydration periods and the amount of added water were also investigated. It was found that the shear strength parameters of HCTCRB were 177 kPa for cohesion （c） and 42~ for the internal friction angle （~）. The hydration period, and the water added in this investigation affected the performance of HCTCRB. However, the related trends associated with such factors could not be assessed. All HCTCRB samples showed stress-dependency behaviour. Based on the stress stages of this experiment, the resilient modulus values of HCTCRB ranged from 300 MPa to 1100 MPa. CIRCLY, a computer program based on the multi-layer elastic theory was used in the mechanistic approach to pavement design and analysis, to determine the performance of a typical pavement model using HCTCRB as a base course layer. The mechanistic pavement design parameters for HCTCRB as a base course material were then introduced. The analysis suggests that the suitable depth for HCTCRB as a base layer for WA roads is at least 185 mm for the design equivalent standard axle （ESA） of 10 million.展开更多
The resilient modulus （RM） of hydrated cement treated crushed rock base （HCTCRB） affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The rela...The resilient modulus （RM） of hydrated cement treated crushed rock base （HCTCRB） affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The related trends of RM corresponding to the different hydration periods still cannot be concluded. Instead, It is found that the moisture content plays more major influence on the RM performance. Higher additional water during compaction of HCTCRB, even at its optimum moisture content and induced higher dry density, led to the inferior RM performance compared to the sample without water addition. The RM of damper samples can be improved through dryback process and superior to that of the sample without water addition at the same moisture content. However, the samples withut water addition during compaction deliver the comparable RM values even its dry density is lower than the other two types. These results indicate the significant influence of moisture content to the performances of HCTCRB with regardless of the dry density. Finally, the experimental results of HCT- CRB and parent material are evaluated with the K-O model and the model recommended by Austroads. These two models provide the excellent fit of the tested results with high degree of determination.展开更多
基金Funded by the National Key Research Program(973 Program)(No.2013CB035901)the National Natural Science Foundation of China(No.51379163)
文摘Combined with DTG analysis, X-Ray diffraction analysis （XRD） and field emission scanning electron microscopy analysis （FSEM） affiliated with energy dispersive spectrometer analysis （EDS）, the early hydration and carbonation behavior of cement paste compacts incorporated with 30% of dolomite powder at low water to cement ratio （0.15） was investigated. The results showed that early carbonation curing was capable of developing rapid early strength. It is noted that the carbonation duration should be strictly controlled otherwise subsequent hydration might be hindered. Dolomite powder acted as nuclei of crystallization, resulting in acceleration of products formation and refinement of products crystal size. Therefore, as for cement-based material, it was found that early carbonation could reduce cement dosages to a large extent and promote rapid strength gain resulting from rapid formation of products, supplemental enhancement due to water release in the reaction of carbonation, and formation ofnanometer CaCO3 skeleton network at early age.
文摘The enhancement of interface bonding between cement and polymerand the structural reticula-tion of the water-soluble polymer areproposed to minimize the shortening of the mechanical properties ofmacro-de-fect-free(MDF)cement based composites at high relativehumidity.The MDF composites incorporated with vari-ouscross-coupling agents studied experimentally.The results show thatthe MDF composites modified with small amounts of cross-couplingagent had raised mechanical properties,but it is more important thatthe modified MDF composites had a significant increase in waterresistance compared to the original one.
文摘1 Scope This standard specifies the term, definition, classification, labeling, technical requirements, test methods, inspection rules, packing, marking, transportation, storage, and quality certificate of spalling resistant bauxite based bricks for cement kiln.
基金supported by the National Natural Science Foundation of China(52273085)the Natural Science Foundation of Henan Province(252300421087).
文摘Radiative cooling has emerged as an attractive passive cooling technology in energy and thermal management fields due to its zero-energy consumption and pollution-free characteristics[[1],[2],[3]].An ideal radiative cooling material should simultaneously exhibit high solar reflectance to minimize solar heat absorption and high infrared emissivity in the“atmospheric window”band(8–13μm)to directly radiate heat to outer space(∼3 K),achieving passive cooling without energy input[[4],[5],[6]].Photonic structures(such as nano-multilayers,nano-pores,and photonic crystals)have been proven to simultaneously achieve high solar reflectance and broadband infrared emissivity[7,8].For instance,commercial“cooling paints”(such as BaSO4 and TiO2-based reflective paints)can reduce surface temperatures by several degrees and moderately decrease building cooling loads.
基金support from the National Natural Science Foundation of China(Grant Nos.:52250010 and 52050128)the Natural Science Foundation of Jiangsu Province(Grant No.:BK20230086)+3 种基金L.P.acknowledges support from the National Natural Science Foundation of China(Grant No.:52201242)the Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001)the Fund of Key Laboratory of Advanced Materials of Ministry of Education(No.AdvMat-2023-12)Z.M.S.acknowledges support from the National Natural Science Foundation of China(Grant No.:U23A20574).
文摘Cement-based materials are the foundation of modern buildings but suffer from intensive energy consumption.Utilizing cement-based materials for efficient energy storage is one of the most promising strategies for realizing zero-energy buildings.However,cement-based materials encounter challenges in achieving excellent electrochemical performance without compromising mechanical properties.Here,we introduce a biomimetic cement-based solid-state electrolyte(labeled as l-CPSSE)with artificially organized layered microstructures by proposing an in situ ice-templating strategy upon the cement hydration,in which the layered micropores are further filled with fast-ion-conducting hydrogels and serve as ion diffusion highways.With these merits,the obtained l-CPSSE not only presents marked specific bending and compressive strength(2.2 and 1.2 times that of traditional cement,respectively)but also exhibits excellent ionic conductivity(27.8 mS·cm^(-1)),overwhelming most previously reported cement-based and hydrogel-based electrolytes.As a proof-of-concept demonstration,we assemble the l-CPSSE electrolytes with cement-based electrodes to achieve all-cement-based solid-state energy storage devices,delivering an outstanding full-cell specific capacity of 72.2 mF·cm^(-2).More importantly,a 5×5 cm^(2) sized building model is successfully fabricated and operated by connecting 4 l-CPSSE-based full cells in series,showcasing its great potential in self-energy-storage buildings.This work provides a general methodology for preparing revolutionary cement-based electrolytes and may pave the way for achieving zero-carbon buildings.
文摘Polypropylene fibres and three sizes of steel fibres reinforced concrete are discussed. The total fibres content ranges from 0 4%-0 95% by volume of concrete. A four point bending test is adopted on the notched prisms with the size of 100?mm×100?mm×500?mm to investigate the effect of hybrid fibres on crack arresting. The research results show that there is a positive synergy effect between large steel fibres and polypropylene fibres on the load bearing capacity in the small displacement range. But this synergy effect disappears in the large displacement range. The large and strong steel fibre is better than soft polypropylene fibre and small steel fibre in the aspect of energy absorption capacity in the large displacement range. The static usage limitation for the hybrid fibres concrete with “wide peak' or “multi peaks' load CMOD pattern should be carefully selected. The ultimate load bearing capacity and the crack width or CMOD at this load level should be jointly considered.
文摘Hydrated Cement Treated Crushed Rock Base （HCTCRB） is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. These methods are not all-encompassing enough to adequately explain the behaviour of HCTCRB in the field. Recent developments in mechanistic approaches have proven more reliable in the design and analysis of pavement, making it possible to more effectively document the characteristics of HCTCRB. The aim of this study was to carry out laboratory testing to assess the mechanical characteristics of HCTCRB. Conventional triaxial tests and repeated load triaxial tests （RLT tests） were performed. Factors affecting the performance of HCTCRB, namely hydration periods and the amount of added water were also investigated. It was found that the shear strength parameters of HCTCRB were 177 kPa for cohesion （c） and 42~ for the internal friction angle （~）. The hydration period, and the water added in this investigation affected the performance of HCTCRB. However, the related trends associated with such factors could not be assessed. All HCTCRB samples showed stress-dependency behaviour. Based on the stress stages of this experiment, the resilient modulus values of HCTCRB ranged from 300 MPa to 1100 MPa. CIRCLY, a computer program based on the multi-layer elastic theory was used in the mechanistic approach to pavement design and analysis, to determine the performance of a typical pavement model using HCTCRB as a base course layer. The mechanistic pavement design parameters for HCTCRB as a base course material were then introduced. The analysis suggests that the suitable depth for HCTCRB as a base layer for WA roads is at least 185 mm for the design equivalent standard axle （ESA） of 10 million.
基金the Australian Research Council(ARC) for financial support under the ARC Linkage Scheme(LP100100734)
文摘The resilient modulus （RM） of hydrated cement treated crushed rock base （HCTCRB） affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The related trends of RM corresponding to the different hydration periods still cannot be concluded. Instead, It is found that the moisture content plays more major influence on the RM performance. Higher additional water during compaction of HCTCRB, even at its optimum moisture content and induced higher dry density, led to the inferior RM performance compared to the sample without water addition. The RM of damper samples can be improved through dryback process and superior to that of the sample without water addition at the same moisture content. However, the samples withut water addition during compaction deliver the comparable RM values even its dry density is lower than the other two types. These results indicate the significant influence of moisture content to the performances of HCTCRB with regardless of the dry density. Finally, the experimental results of HCT- CRB and parent material are evaluated with the K-O model and the model recommended by Austroads. These two models provide the excellent fit of the tested results with high degree of determination.
