| The hydraulic concrete suffered freezing and thawing cycle damage,and the erosion damage of salt ions has become the main factor causing the decay of the durability of hydraulic concrete materials in Northwest China,and seriously affecting the safety and efficiency of water conservancy projects in these areas.According to the influence of the hydraulic structures bear the salt ion erosion and freeze-thaw cyclic effect in northwest cold-drought irrigation area,result in the problem of concrete durability attenuation,relying on the Henan province science and technology innovation talent support program "Durability attenuation law research of hydraulic concrete structure under the effect of erosion and freeze-thaw composite" and Graduate Student Innovation Project of North China University of Water Resources and Electric Power(YK2015-01),though surveying the hydraulic concrete material erosion environment of northwest typical irrigation area,Jingtai electric irrigation area,and analyzing water samples,soil samples and concrete around the concrete buildings under erosion damage,in chemical and XRD ray diffraction analyzes,clear and definite the main erosion medium of concrete material.Concrete rapid freeze-thaw experiment was designed to explore the different water binder ratio,different amount of fly ash,different dosage of air entraining agent of concrete.The mass loss and dynamic elastic modulus changes as durability index,and the durability of attenuation damage process and mechanism of hydraulic concrete material was explored in the effect of water,3.5% NaCl solution,5%2 4Na SO solution and 3.5% NaCl +5%2 4Na SO Composite solution.Meanwhile,combine with measured material parameters of indoor accelerated test,Establish ANSYS finite element model of the water tower structure in Jingtai electric irrigation area for numerical simulation analysis.The water tower structure was taken static and dynamic analysis in salt effect before and after the cold under the action of different working conditions,which bear deadweight,wind force,crowd load,and earthquake load,which obtained the following conclusions:This paper implement combined with,though indoor accelerated test and numerical simulation,which obtained the following conclusions:(1)The low water-binder concrete adding proper amount of air-entraining agent ratio have good durability of salt frost resistance,fly ash concrete should take certain measures of antifreeze in freezing area requires.(2)The concrete has different effects of the frost resistance durability in different erosion solution Under the effect of freeze-thaw cycles,The influence degree of various erosion media on concrete quality the order from strong to weak is 3.5% NaCl +5%2 4Na SO >3.5% NaCl >5%2 4Na SO >water;The influence of dynamic elastic modulus of concrete order is: 3.5% NaCl +5%2 4Na SO >5%2 4Na SO >3.5% NaCl >water?(3)The ANSYS finite element model of the water tower structure can arrive that,a top bracket and contact with the base part of the tower structure is the most vulnerable to damage.The dynamic loading impact is greater than the static load effect on the tower structure on water tower in salt freezing erosion loading.Through the study of combination of effects on the properties of salt resistance of concrete in Northwest China frozen Jingdian Irrigation,can provide certain reference value for the similar projects for prevention and treatment of cold and drought in Northwest irrigation area of concrete structure erosion degradation,prolong the service life of concrete structure,promote the sustainable development of China's Northwest arid irrigation district economy,plays an important role in maintaining the ecological environment in northwest region. |
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