Durability Of Concrete Materials In Flu Gus Cooling Tower Under Simulated Environmental Solutions

The inner wall of cooling tower using the the technology of chimney-tower integrated contains large amount of SO42-, NO3-, H+, which can corrode the inner wall. So far the main material of cooling tower body is still using normal concrete. In the operation process, the corrosion of inner wall and water spray frame is very serious. The splitting tensile strength, neutral depth, reinforcement corrosion rate and chloride ion concentration of NC30 normal concrete, HPC30 and HPC50 high performance concrete, and RJPC reactive powder concrete are comparative studied by simulating the immersion test of corrosive solution and deacidification solution, and then predict the life expectancy. The main conclusions are shown as follows:(1) After immersion in two kinds of simulated solution, the split tensile strength of normal concrete and high performance concrete increased at beginning and decreased later,while the split tensile strength of reactive powder concrete in two kinds of simulated solution had been in a state of decline. The largest loss of splitting tensile strength was normal concrete in the end of immersion.(2) The normal concrete, high performance concrete and reactive powder concrete in two kinds of simulated corrosion solution, their variation law of neutral depth, corrosion rate of the steel bar and concentration of chloride ion showed the same variation rule. The neutral depth increased with the extension of soaking time, the rebar corrosion rate has always be zero, the chloride ion concentration decreased with the increasing of soaking time.(3) The durability indicator variation of the concrete in the simulation solution without acied is generally small than indicators in acied solution under the same immersion time. This is because the lack of H+in solution without acied reduces the corrosion.(4) Considering chloride ion concentration is the main factor to predict the life expectancy of concrete structure, the numerical simulation is carried out by using Monte Carlo method to get the service life accord with Weibull distribution. The life time of NC30,HPC50,HPC30,RPC can achieve to 2.84a,4.07a,4.60a,8.79a at 10% probability of failure after immersion in the electric acceleration simulated corrosion solution.We can conclude that RPC has the longest service life under the same condition.