The increasing anthropogenic CO2 emission and global warming has challenged the China and other countries to seek new and better ways to meet the world’s increasing need for energy while reducing greenhouse gas emiss...The increasing anthropogenic CO2 emission and global warming has challenged the China and other countries to seek new and better ways to meet the world’s increasing need for energy while reducing greenhouse gas emissions.The overall proposition of this research is to develop a brand-new CO2 physical and chemical sequestration method by using solid waste of coal mining and cementitious material which are widely used for goaf backfilling in coal mining.This research developed a new testing system(constant temperature pressurized reaction chamber(CTPRC))to study the effects of different initial parameters on mineral carbonation such as different initial water-binder ratio,initial sample porosity and initial carbon dioxide pressure.The experimental results show that the CO2 consumption ratio is 15%,10%and 7%higher with relatively high initial water-binder ratio,initial sample porosity and initial CO2 pressure within 48 h.In addition,some physical and chemical evidence was found through the electron microscope scanning and XRD test to further explain the above test results.This proposed research will provide critical parameters for optimizing CO2 sequestration capacity in this cementitious backfilling material with forming agent.展开更多
Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a ...Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a distributed measurement system for in-situ soil moisture content （SM-DTS） is introduced.The system is based on carbon-fiber heated cable （CFHC） technology that has been developed to enhancethe measuring accuracy of in-situ soil moisture content. Using CFHC technique, a temperature characteristicvalue （Tt） can be defined from temperatureetime curves. A relationship among Tt, soil thermalimpedance coefficient and soil moisture content is then established in laboratory. The feasibility of theSM-DTS technology to provide distributed measurements of in-situ soil moisture content is verifiedthrough field tests. The research reported herein indicates that the proposed SM-DTS is capable ofmeasuring in-situ soil moisture content over long distances and large areas.展开更多
Lithium ion batteries(LIB)can rupture and result in thermal runaway and battery fires.In the process of transporting lithium ion batteries using trains,the massive collection of batteries can cause train fire and pose...Lithium ion batteries(LIB)can rupture and result in thermal runaway and battery fires.In the process of transporting lithium ion batteries using trains,the massive collection of batteries can cause train fire and pose significant danger to the public.This is especially critical when the fire occurs amid a heavily populated metropolitan environment.This paper reports the 3D analysis of a warehouse with possible train fire due to LIB rupture and the fire propagation at a rail yard.Six critical fire cases with the battery train in close vicinity to the warehouse were considered.The six fire cases are the worst-case scenarios of a Monte Carlo simulation of different fire cases that may occur to an actual steel storage facility at the Capital Railyard,Raleigh,North Carolina.A 3D finite element(FE)frame model was constructed for the steel warehouse and the most critical fire cases were simulated.The results indicated that several structural components of the warehouse would experience large stresses and deflections during the simulated battery fires and resulting in instability to the structure.Specifically,members of the roof frame represent the most critical elements and that the members can result in large deformations as early as 4 minutes after the fire starts.Furthermore,effective utilization of fire protection can delay somewhat the fire effects and extend time to failure to 45 minutes and in one of the simulated cases,prevent structural instability.Thus,fire from LIB waste transport using train is a very realistic problem due to the thermal runaway,and the analysis performed in current study can be used as a preventive investigation technique for buildings that may be exposed to the train fire risk.展开更多
Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such a...Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such as trains,the massive collection of battery stacks required to meet energy demands may pose a significant hazard.The objective of this paper is to review the risk evaluation processes for train fires and investigate the propagation of lithium ion battery fire to a neighboring steel warehouse structure at a rail repair shop through a case study.The methodology of the analyses conducted include a Monte Carlo-based dynamic modeling of fire propagation potentials,an expert-based fire impact analysis,and a finite element(FE)nonlinear fire analysis on the structural frame.The case study is presented as a demonstration of a holistic fire risk analysis for the lithium ion battery fire and results indicate that significant battery fire mitigations strategies should be considered.展开更多
Portland cement concrete （PCC） and asphalt concrete （AC） are the most common roadway and highway construction materials which are more suitable for continuous slab pave- ments. The durability of these materials is...Portland cement concrete （PCC） and asphalt concrete （AC） are the most common roadway and highway construction materials which are more suitable for continuous slab pave- ments. The durability of these materials is highly dependent on construction quality and techniques, and both materials are difficult to repair. Heavy rain storms in India have recently revealed several roadway pavement failures and resulted in significant repair costs. Interlocking block type pavements are simpler to construct and maintain than both PCC and AC pavements but, have only been used for slower traffic roads due to weak interlocking at the joints. To improve the quality of block pavements, blocks made of PCC with waste tire crumb rubber partially replacing river sand （fine aggregate） are suggested. The joint interlocks can be further improved by modifying the block geometry. The material is completely recycled and is deemed more superior than concrete pavements when repair and construction techniques and costs are concerned. This paper presents the material characterization of Rubberized Concrete Blocks （RCBs） using crumb rubber particle size ranging from 0.075 mm to 4.75 mm to partially replace the fine aggregates. It also discusses the advantages of RCB over continuous material pavements.展开更多
基金the National Natural Science Foundation of China(No.51304207)the Fundamental Research Funds for the Key Laboratory of Coal-based CO2 capture and geological storage,China University of Mining and Technology(No.2016A03).
文摘The increasing anthropogenic CO2 emission and global warming has challenged the China and other countries to seek new and better ways to meet the world’s increasing need for energy while reducing greenhouse gas emissions.The overall proposition of this research is to develop a brand-new CO2 physical and chemical sequestration method by using solid waste of coal mining and cementitious material which are widely used for goaf backfilling in coal mining.This research developed a new testing system(constant temperature pressurized reaction chamber(CTPRC))to study the effects of different initial parameters on mineral carbonation such as different initial water-binder ratio,initial sample porosity and initial carbon dioxide pressure.The experimental results show that the CO2 consumption ratio is 15%,10%and 7%higher with relatively high initial water-binder ratio,initial sample porosity and initial CO2 pressure within 48 h.In addition,some physical and chemical evidence was found through the electron microscope scanning and XRD test to further explain the above test results.This proposed research will provide critical parameters for optimizing CO2 sequestration capacity in this cementitious backfilling material with forming agent.
基金The financial supports provided by the National Natural Science Foundation of China(Grant Nos.41230636,41372265,41427801)National Basic Research Program of China(973 Project)(Grant No.2011CB710605)
文摘Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a distributed measurement system for in-situ soil moisture content （SM-DTS） is introduced.The system is based on carbon-fiber heated cable （CFHC） technology that has been developed to enhancethe measuring accuracy of in-situ soil moisture content. Using CFHC technique, a temperature characteristicvalue （Tt） can be defined from temperatureetime curves. A relationship among Tt, soil thermalimpedance coefficient and soil moisture content is then established in laboratory. The feasibility of theSM-DTS technology to provide distributed measurements of in-situ soil moisture content is verifiedthrough field tests. The research reported herein indicates that the proposed SM-DTS is capable ofmeasuring in-situ soil moisture content over long distances and large areas.
文摘Lithium ion batteries(LIB)can rupture and result in thermal runaway and battery fires.In the process of transporting lithium ion batteries using trains,the massive collection of batteries can cause train fire and pose significant danger to the public.This is especially critical when the fire occurs amid a heavily populated metropolitan environment.This paper reports the 3D analysis of a warehouse with possible train fire due to LIB rupture and the fire propagation at a rail yard.Six critical fire cases with the battery train in close vicinity to the warehouse were considered.The six fire cases are the worst-case scenarios of a Monte Carlo simulation of different fire cases that may occur to an actual steel storage facility at the Capital Railyard,Raleigh,North Carolina.A 3D finite element(FE)frame model was constructed for the steel warehouse and the most critical fire cases were simulated.The results indicated that several structural components of the warehouse would experience large stresses and deflections during the simulated battery fires and resulting in instability to the structure.Specifically,members of the roof frame represent the most critical elements and that the members can result in large deformations as early as 4 minutes after the fire starts.Furthermore,effective utilization of fire protection can delay somewhat the fire effects and extend time to failure to 45 minutes and in one of the simulated cases,prevent structural instability.Thus,fire from LIB waste transport using train is a very realistic problem due to the thermal runaway,and the analysis performed in current study can be used as a preventive investigation technique for buildings that may be exposed to the train fire risk.
基金The authors would like to acknowledge the funding received under NCDOT Project#2020-40.Additional funding also received from the UNC Charlotte College of Engineering Dean’s Office.Dean Bob Johnson’s support of this effort is greatly appreciated.
文摘Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such as trains,the massive collection of battery stacks required to meet energy demands may pose a significant hazard.The objective of this paper is to review the risk evaluation processes for train fires and investigate the propagation of lithium ion battery fire to a neighboring steel warehouse structure at a rail repair shop through a case study.The methodology of the analyses conducted include a Monte Carlo-based dynamic modeling of fire propagation potentials,an expert-based fire impact analysis,and a finite element(FE)nonlinear fire analysis on the structural frame.The case study is presented as a demonstration of a holistic fire risk analysis for the lithium ion battery fire and results indicate that significant battery fire mitigations strategies should be considered.
文摘Portland cement concrete （PCC） and asphalt concrete （AC） are the most common roadway and highway construction materials which are more suitable for continuous slab pave- ments. The durability of these materials is highly dependent on construction quality and techniques, and both materials are difficult to repair. Heavy rain storms in India have recently revealed several roadway pavement failures and resulted in significant repair costs. Interlocking block type pavements are simpler to construct and maintain than both PCC and AC pavements but, have only been used for slower traffic roads due to weak interlocking at the joints. To improve the quality of block pavements, blocks made of PCC with waste tire crumb rubber partially replacing river sand （fine aggregate） are suggested. The joint interlocks can be further improved by modifying the block geometry. The material is completely recycled and is deemed more superior than concrete pavements when repair and construction techniques and costs are concerned. This paper presents the material characterization of Rubberized Concrete Blocks （RCBs） using crumb rubber particle size ranging from 0.075 mm to 4.75 mm to partially replace the fine aggregates. It also discusses the advantages of RCB over continuous material pavements.
