The article takes a simply supported prestressed concrete small box girder bridge project as an example for inspection and evaluation after a fire incident.This includes appearance detection,concrete color hardness de...The article takes a simply supported prestressed concrete small box girder bridge project as an example for inspection and evaluation after a fire incident.This includes appearance detection,concrete color hardness detection,concrete strength detection,concrete surface damage layer detection,reinforcement protective layer detection,and concrete carbonation detection.It is hoped that this analysis can be used as a reference for the detection and evaluation of future bridge projects with fire incidents to smoothen its subsequent repair and maintenance.展开更多
The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities...The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to deter- mine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly in- crease soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0% to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m^3 is 2.8 times higher than that at 1.4 Mg/m^3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interracial mechanical interaction between fibre surface and soil matrix.展开更多
The reinforcement corrosion is the pitting corrosion of chloride corrosion.Hence,in this study,the variations of reinforcement tensile strength due to stress concentration of pitting corrosion are analyzed.The stress ...The reinforcement corrosion is the pitting corrosion of chloride corrosion.Hence,in this study,the variations of reinforcement tensile strength due to stress concentration of pitting corrosion are analyzed.The stress concentration consequence of corrosion on the reinforcement tensile capacity is studied utilizing tension tests and creating different ABAQUS software models.According to the modelling in various corrosion depths,strength reduction is less than 5%in corrosion with pit radius to reinforcement diameter ratio up to 0.3 and for corrosions higher than 0.4,the measure of capacity reduction is increased more to 30%.展开更多
This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, t...This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional (UD) laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer (CFRP) has been addressed by comparing the energy release rates, obtained by testing double cantilever beam (DCB) samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.展开更多
文摘The article takes a simply supported prestressed concrete small box girder bridge project as an example for inspection and evaluation after a fire incident.This includes appearance detection,concrete color hardness detection,concrete strength detection,concrete surface damage layer detection,reinforcement protective layer detection,and concrete carbonation detection.It is hoped that this analysis can be used as a reference for the detection and evaluation of future bridge projects with fire incidents to smoothen its subsequent repair and maintenance.
基金supported by the National Natural Science Foundation of China(Grant Nos.41072211,41322019)Natural Science Foundation of Jiangsu Province(Grant No.BK2011339)Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology)(SKLGP2013K010)
文摘The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to deter- mine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly in- crease soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0% to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m^3 is 2.8 times higher than that at 1.4 Mg/m^3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interracial mechanical interaction between fibre surface and soil matrix.
文摘The reinforcement corrosion is the pitting corrosion of chloride corrosion.Hence,in this study,the variations of reinforcement tensile strength due to stress concentration of pitting corrosion are analyzed.The stress concentration consequence of corrosion on the reinforcement tensile capacity is studied utilizing tension tests and creating different ABAQUS software models.According to the modelling in various corrosion depths,strength reduction is less than 5%in corrosion with pit radius to reinforcement diameter ratio up to 0.3 and for corrosions higher than 0.4,the measure of capacity reduction is increased more to 30%.
文摘This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional (UD) laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer (CFRP) has been addressed by comparing the energy release rates, obtained by testing double cantilever beam (DCB) samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.