Study On Durability Of Freeze-thaw Resistance Of Airport De-icing Concrete

Based on the current situation of rapid damage of pavement surface caused by freezing and thawing damage of concrete pavement under the condition of snow removal in northern airport in winter,the influence of surface damage of de-icing concrete pavement on the surface damage caused by ethylene glycol and other deicer solutions was studied.The effects of different concentrations of ethylene glycol solution on the freeze-thaw damage of the de-icing concrete pavement at the airport were studied by experiments.The effects of different concentrations of ethylene glycol solution on the freeze-thaw damage of concrete were discussed.Based on the theoretical analysis of frost heave of concrete surface pores,the damage effect of pores in the surface layer of concrete on the concrete surface was studied by numerical simulation method.The separation of different pore distributions in the surface layer of concrete pavement was infiltrated into the deionized solution.In the process of melt damage,the stress distribution state of single-hole icing expansion at different depths of the surface layer,the relationship between stress and depth,and the relationship between the mutual coupling effect of the pore solution during double-hole icing on the surface stress are analyzed..The results of the experimental study show that when the concentration of ethylene glycol in the surface of the concrete is low,the freeze-thaw damage to the pavement is more serious,and the concentration of the ethylene glycol solution is significantly higher at a concentration between 3.5% and 25%.At 3.5%,the freeze-thaw damage of the concrete pavement is not slight.The numerical analysis shows that the concrete layer surface layer is inevitably cracked and cracked,and the ethylene glycol solution will penetrate into the concrete surface along these cracks and will be concrete.The road surface causes severe frost heaving stress,and the stress develops fastest along the aggregate interface,which is more likely to cause local surface spalling;the pore expansion stress is transmitted to the concrete surface layer and the size of the pore b and the solution in the pore The expansion ratio is proportional and inversely proportional to the square d2 of the distance from the pore distance.When the adjacent two holes are coupled with each other,the relationship between the distance D between the holes and the size b of the hole is the key factor for controlling the mutual stress.When the ratio of the distance to the radius D/b is 2.4,the stress is affected by 50%.about.And the mutual stress effect will decrease rapidly with increasing distance.When the air entraining agent is added,the pore size of the pores is d,and the distance from the ice pores is D.When D/d is 1,the effect on the swelling pores of the ice is about 42%.The effect will decrease rapidly with the increase of D/d.When D/d is greater than or equal to 3,the effect will be below 1%.When an open hole with a pore diameter of 0.15mm~0.2mm appears on the surface of the concrete and the depth is greater than 5mm,the surface layer of the pavement will suffer serious surface damage after 30 freeze-thaw cycles.