This paper presents two possible construction methods that could be adopted in the Wenchuan post-earthquake reconstruction.One is the composite tubular construction and the other is FRP(Fibre Reinforced Polymer) retro...This paper presents two possible construction methods that could be adopted in the Wenchuan post-earthquake reconstruction.One is the composite tubular construction and the other is FRP(Fibre Reinforced Polymer) retrofitting technology.The background of these two methods,the existing research and relevance to Whenchuan post-earthquake reconstruction are described.展开更多
The "5·12" Wenchuan Earthquake presents two challenges-reconstruction of the devastated areas and building adequate seismic resistance into the rest of China.The stages in recovery include structural co...The "5·12" Wenchuan Earthquake presents two challenges-reconstruction of the devastated areas and building adequate seismic resistance into the rest of China.The stages in recovery include structural condition assessment,identification of seismic weaknesses,appreciation of the variable seismicity of PR China,the development of a seismic performance index to aid the decision to relocate,rebuild or retrofit,development and application of the principles of retrofitting which recycles rubble and waste from Wenchuan "5·12",with an emphasis on integrating masonry construction into seismic resistance.The recovery and resilience achieved through structural engineering must be integrated into a broader community involvement in disaster risk reduction.展开更多
To understand the effect of steam curing temperature on the hydrate and microstructure of hardened cement paste,several measuring methods including X-ray diffraction(XRD),atomic absorption spectroscopy(ASS),ion chroma...To understand the effect of steam curing temperature on the hydrate and microstructure of hardened cement paste,several measuring methods including X-ray diffraction(XRD),atomic absorption spectroscopy(ASS),ion chromatography,conductivity meter,alternating-current impedance spectroscopy and nuclear magnetic resonance(NMR)are employed to investigate the hydration characteristics,pore solution composition and conductivity,resistivity and pore structure during the steam curing process.Experimental results show that steam curing promotes the hydration process,greatly raises the resistivity,and decreases the porosity of specimen at early age.Compared with being treated at 45℃,higher temperature leads to a fast decomposition of ettringite at initial stage of the constant temperature treatment period,which improves the relative content and ionic activity of the conductive ions in pore solution.Furthermore,the number of pores larger than 200 nm increases significantly,which reduces the resistivity of the hardened cement paste.Cement paste treated at 45℃ has a more stable and denser microstructure with less damages.展开更多
文摘This paper presents two possible construction methods that could be adopted in the Wenchuan post-earthquake reconstruction.One is the composite tubular construction and the other is FRP(Fibre Reinforced Polymer) retrofitting technology.The background of these two methods,the existing research and relevance to Whenchuan post-earthquake reconstruction are described.
文摘The "5·12" Wenchuan Earthquake presents two challenges-reconstruction of the devastated areas and building adequate seismic resistance into the rest of China.The stages in recovery include structural condition assessment,identification of seismic weaknesses,appreciation of the variable seismicity of PR China,the development of a seismic performance index to aid the decision to relocate,rebuild or retrofit,development and application of the principles of retrofitting which recycles rubble and waste from Wenchuan "5·12",with an emphasis on integrating masonry construction into seismic resistance.The recovery and resilience achieved through structural engineering must be integrated into a broader community involvement in disaster risk reduction.
基金Projects(U1534207,11790283,51878583)supported by the National Natural Science Foundation of China。
文摘To understand the effect of steam curing temperature on the hydrate and microstructure of hardened cement paste,several measuring methods including X-ray diffraction(XRD),atomic absorption spectroscopy(ASS),ion chromatography,conductivity meter,alternating-current impedance spectroscopy and nuclear magnetic resonance(NMR)are employed to investigate the hydration characteristics,pore solution composition and conductivity,resistivity and pore structure during the steam curing process.Experimental results show that steam curing promotes the hydration process,greatly raises the resistivity,and decreases the porosity of specimen at early age.Compared with being treated at 45℃,higher temperature leads to a fast decomposition of ettringite at initial stage of the constant temperature treatment period,which improves the relative content and ionic activity of the conductive ions in pore solution.Furthermore,the number of pores larger than 200 nm increases significantly,which reduces the resistivity of the hardened cement paste.Cement paste treated at 45℃ has a more stable and denser microstructure with less damages.
