| This paper use the Yu Hongfa group freeze-thaw life prediction model established the relationship between the indoor and field concrete freeze-thawing, statistics the valuable national historical meteorological data, combined forecasting model theory put forward the concrete durability regionalization, reference the zoning the durability of the concrete structure design in airport salt freeze-thawing environment, and obtained the following innovative results:1, From the durability of concrete on the basis of theory, determine the frost resistance of concrete environmental regionalization index, delves into the cold concrete freeze-thaw cycle, has been clear about the indoor freezing method, outdoor engineering based on water frozen and salt frozen environment index, and to determine the indoor quick frozen principle. These led water frozen and frost damage criteria.2,- 3℃ as freeze-thaw cycle of outdoor temperature points alternately, in detail elaborated the temperature data statistical analysis method and process. To compile most of the minimum temperature, air temperature, maximum cooling speed of mu level diagram and the sigma level diagram, the revised standards level diagram. At the same time, around 520 feature points plus or minus temperature alternating map in the positive and negative temperature alternating frequency level, studies the day 32 kinds of circulation situation of freeze-thaw cycles, on this basis to get the freezing and thawing cycle level diagram. Analysis it is concluded that altitude rises with the increase of latitude cause freezing and thawing cycles, elevation height and latitude size is two kinds of cause of freeze-thaw cycles change.3, Based on the concrete freezing and thawing Yu Hongfa group natural environment life mathematical model has carried on the concrete durability life prediction, the model is discussed and Li Jinyu group, the differences between the Jin Weiliang group prediction model and advantages, and the conversion relationship for indoor and outdoor freeze-thaw cycles in 1:7 ~ 1:8, rather than Li Jinyu group, Jin Weiliang group research important point between 1:10 ~ 1:15. Based on the durability of concrete structure design code division level of the engineering environment, put forward two methods of the three indicators affect concrete frost resistance of concrete weight, got to a fixed area, the influence factors of concrete freeze-thaw damage, outdoor freeze-thaw cycles of frost resistance is one of the biggest, the influence of ratio can reach 90%, the second is day minimum temperature degrees, accounted for 8%, the last is maximum cooling speed, accounted for 2% of important conclusions. With indoor quick frozen 50 times as a benchmark, predict the concrete freezing and thawing of life across the country, to draw the concrete durability division charts.4, Send Yu Hongfa group model with the combination of Li Jinyu group group model, the air content, water/cement ratio, concrete frost resistance parameters such as dosage of fly ash and concrete freeze-thaw outdoor freeze-thaw cycles, stress, and years of life than 6 groups of parameters, and indoor concrete freeze-thaw cycles played a link key role here. On the basis of this, the frost resistance of concrete zoning and frost resistance of concrete parameters. Then in the concrete structure design uses level at the same time, determine the four kinds of concrete structure design uses level respectively in the hierarchy of seven antifreeze antifreeze parameters, to map the assumption that water cement ratio of 0.45 in the air content of concrete under different design of contour map and assume that air content was 5% in concrete under different design of water-binder ratio contour map. Finally summarized a set of parameters based on frost resistance of concrete mixture ratio design process, in view of the frost resistance design are proposed.5, Analyzes the erosion mechanism of concrete under salt frozen environment around the concrete frost resistance and freeze-thaw medium, discussed the relationship between improved Yu Hongfa group freeze-thaw fatigue equation, make it not only applies to the water environment, and is suitable for the salt frozen environment, accord with actual engineering environment more; Drawing based on six different frost resistance of concrete under freeze-thaw medium zoning map, frost resistance parameter design to meet various environment needs; Ordinary concrete are analyzed and two kinds of high performance concrete under the effect of different freezing and thawing media, the freezing and thawing life OPC40 freeze-thaw life from big to small in turn is: CMA>Water>EG≈PG > KAC≈NAC≈Na Cl, HPC40S30 freeze-thaw life from big to small in turn is: Water≈CMA≈NAC>PG>EG>Na Cl≈KAC, HPC50F20 freeze-thaw life from big to small in turn is: CMA>NAC≈PG>Water≈EG≈KAC≈Na Cl; In cold regions in major airports, roads and other infrastructure construction, suggests using the high performance concrete, and according to the different location to choose corresponding deicing fluid at the airport.6, Around the area of the durability of pavement concrete and frost resistance parameter design in the national general, accuracy, north, northwest and northeast city airport three sample for actual engineering verification, and according to the actual situation inspection with cold water engineering of concrete, are proposed according to the situation of salt frozen in the airport operation management in addition to the ice. |
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