Durability And Service Life Research Of Reinforced Concrete Bridge Deck In Salt-Freezing-thawing Circle Environment

Reinforced concrete structure is the most popular structural form. The chloride ion intrusion of the concrete lead to steel bar depassivation and corrosion in saline-alkali land in the west and road or bridge engineering with application of snow melt agent in the north. As the occurrence and development of corrosion, corrosion product volume expanse and concrete cover expanses cracked and spalling.Then durability damage of the concrete structure happens. Reinforced concrete bridge deck is most seriously and directly salt-freeze-thaw-damaged of all the the bridge component. It is urgently.needs to solve the problem that life prediction under salt-freeze-thaw environment before in design, assessment and maintenance. This article summarized predecessors’research about reinforced concrete structure under freezing and thawing test, choosing reinforced concrete bridge deck as the research object. Then we designed and producted15beam specimen,75pull-out test specimen and each kind of specimen has3contrasts.At last,we will measure and research the specimen after designated freeze-thaw cycle. In this paper, main work is as follows:1. Chosing12100mm×100mm X400mm test specimen to do the salt-freeze-thaw test. The number of cycles are50,100,150.During the test,we measure the quality and the dynamic modulus of elasticity every25cycles at a time.2. Chosing72pull-out test specimen to do the salt-freeze-thaw test. The number of cycles are50,100,150.There are strain gauges in the specimen.We carry out pull-out test after the freeze-thaw test.Then measure bond stress,relative slippage between concrete and steel bar.3.We take concrete on the surfice,25cm inner and reinforced concrete interface to do electron microscopy experiment after the pull-out test. And then measure the content of chloride ions in different depth, observe hydrate morphology and pore structure. Exploring the chloride ions distribution and diffusion about different cycle numbers,different chloride ion concentration and different depth.4.Choosing quality lossing,dynamic modulus of elasticity,steel bond stress as the parameter.We can amend the mathematical model of trodatinal reinforced concrete bridge deck’s endurance life after salt-freez-thaw by setting up mathematical model based on reliability theory. Finally,we can explore and put forward scientific and accurate methods to predict the endurance life of bridge deck structure.