Study On The Durability Of Concrete Bridges In High-cold Region Of Xinjiang

Because of the special geographical position, most parts of Xinjiang is a typical high-cold region and has a nasty natural environment,then we need higher requirements for roads and bridges. For transport safety consideration, they usually spreading de-icing salt on the road as a result of the large snowfall in high-cold region, reduce the freezing point of snow and improve pavement skid resistance. But the bridge and curbstone and other concrete structures are subjected to salt water corrosion and therefore freeze-thaw damage, the destruction of this salt-cold coupling strength is much larger than normal freeze-thaw damage, and causing a lot of bridges in Xinjiang durability damage occurred, that's a serious threat to people's lives property.This studing carried out durability of concrete bridges in high-cold regions in allusion to the bridge concrete environment and rely on Guozigou Bridge project.Aimed at improving the resistance to freeze-thaw,corrosion and carbonation.The results not only for the high-cold regions of Xinjiang,but also other cold areas.In this studying, we had a large number of field disease investigation about concrete bridge in Xinjiang and analysised of various typical causes disease, and provided a strong geographical data to support the durability design division; because of the large winter snowfall,high altitude,wind speed and fast drop temperature in the support projects,we have a clear thinking about working environment,corrosive environment and the durability rating on different structural parts of concrete bridge. Combined with the characteristics and mechanism of damage about durability of concrete bridges in this area, selection of local raw materials for the concrete bridge, designed the orthogonal contrast test and comparative test to do this studying, and had a optimal design for durabilitythe in main tower, deck, piers and large volume cap on the bridge. The studying focused on resistance to chloride ion penetration, salt-cold coupling and anti-carbonation in different parts of the concrete bridge structure in high-cold region. Based on the date analysis and laboratory tests, the studying revealed the influencd law of mix design parameters for the durability of concrete bridges in different parts structure. Established a ralatedness between chloride ion penetration, salt-cold coupling and anti-carbonation through the correlation analysis. Synthesize the theoretical analysis and experimental data, presented the durability of concrete bridge design control indicators in different location of Xinjiang, and the composition of the recommended value for durability of concrete bridges in different parts. Through the life-cycle cost analysis and found that the durability of concrete in high-cold region has obvious economic advantages, with the great application and popularization.