In this research, the flame retardancy of neat alginate fiber, flame retardant viscose fiber （FRV） and alginate/FRV （50/50） blending fibers were investigated by vertical burning and cone calorimeter tests. The ver...In this research, the flame retardancy of neat alginate fiber, flame retardant viscose fiber （FRV） and alginate/FRV （50/50） blending fibers were investigated by vertical burning and cone calorimeter tests. The vertical burning test showed that the afterflame time of alginate fiber was 0 s, but alginate presented serious smoldering behavior with the afterglow time of 605 s and damaged length of 85 mm, while the afterglow time of FRV was 0 s. When the FRV was incorporated into alginate with the weight ratio of 50/ 50, the afterglow time and damaged length were significantly reduced to 85 s and 35 mm, indicating the smoldering of alginate can be effectively decreased. The morphology and chemical structure of the alginate residual demonstrated that it was seriously destroyed during smoldering process, which was ascribed to its relative low initial thermal degradation temperature. Based on the thermal properties analysis, alginate and FRV fibers shared the concurrence of rapid degradation in the same temperature region of 250-300 ℃, through which, the compact and stable char formed by FRV can prevent the heat transmission and suppress the smoldering of alginate. Further, the cone calorimeter results demonstrated that the time to ignition （TTI） significantly increased and peak heat release rate （PHRR） decreased for alginate/FRV （50/50） compared with FRV. With this research, a new method to overcome the smoldering of alginate was proposed by blending with FRV展开更多
A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and t...A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt （PA） and flame-retarded porous asphalt （FRPA） were studied comparing with cement concrete pavement, dense-graded lIMA and SMA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.展开更多
A new structural system called a stepped wall-frame structure is proposed in this study to solve the bottom yielding problem of RC frames, which widely occurred during previous earthquakes such as thc Wcnchuan and Yus...A new structural system called a stepped wall-frame structure is proposed in this study to solve the bottom yielding problem of RC frames, which widely occurred during previous earthquakes such as thc Wcnchuan and Yushu earthquakes in China. A 1/5 scale ordinary RC frame model and a stepped wall-frame model were subjected to shake table motions together to study the seismic behavior of the new structural system. This paper presents the dynamic characteristics, the seismic responses and the failure and collapse mechanism of the two models under low, moderate and high intensity shaking. The test results and further analysis demonstrate that the seismic performance of stepped wall-frame structures is superior to ordinary RC frames in terms of the well-controlled deformation pattern and more uniformly distributed damage. The stepped wall can effectively suppress the bottom yielding mechanism, and is simple, economical and practical tbr engineering practice.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No. CUSF-DH-D2016012)
文摘In this research, the flame retardancy of neat alginate fiber, flame retardant viscose fiber （FRV） and alginate/FRV （50/50） blending fibers were investigated by vertical burning and cone calorimeter tests. The vertical burning test showed that the afterflame time of alginate fiber was 0 s, but alginate presented serious smoldering behavior with the afterglow time of 605 s and damaged length of 85 mm, while the afterglow time of FRV was 0 s. When the FRV was incorporated into alginate with the weight ratio of 50/ 50, the afterglow time and damaged length were significantly reduced to 85 s and 35 mm, indicating the smoldering of alginate can be effectively decreased. The morphology and chemical structure of the alginate residual demonstrated that it was seriously destroyed during smoldering process, which was ascribed to its relative low initial thermal degradation temperature. Based on the thermal properties analysis, alginate and FRV fibers shared the concurrence of rapid degradation in the same temperature region of 250-300 ℃, through which, the compact and stable char formed by FRV can prevent the heat transmission and suppress the smoldering of alginate. Further, the cone calorimeter results demonstrated that the time to ignition （TTI） significantly increased and peak heat release rate （PHRR） decreased for alginate/FRV （50/50） compared with FRV. With this research, a new method to overcome the smoldering of alginate was proposed by blending with FRV
基金Hi-tech Research and Development Program of China (863 Program of China) (No.2006AA11Z117)
文摘A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt （PA） and flame-retarded porous asphalt （FRPA） were studied comparing with cement concrete pavement, dense-graded lIMA and SMA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.
基金Special Fund for Earthquake Research under Grant No.201208013National key Technology R&D Program under Grant No.2012BAK15B05Basic Research Fund of Institute of Engineering Mechanics,CEA under Grant No.2010A04
文摘A new structural system called a stepped wall-frame structure is proposed in this study to solve the bottom yielding problem of RC frames, which widely occurred during previous earthquakes such as thc Wcnchuan and Yushu earthquakes in China. A 1/5 scale ordinary RC frame model and a stepped wall-frame model were subjected to shake table motions together to study the seismic behavior of the new structural system. This paper presents the dynamic characteristics, the seismic responses and the failure and collapse mechanism of the two models under low, moderate and high intensity shaking. The test results and further analysis demonstrate that the seismic performance of stepped wall-frame structures is superior to ordinary RC frames in terms of the well-controlled deformation pattern and more uniformly distributed damage. The stepped wall can effectively suppress the bottom yielding mechanism, and is simple, economical and practical tbr engineering practice.
