Experiment Of Anti-chloride-permeability About Concrete Using Granulated Blast Furnace Slag Fine Aggregates

A large number of engineering practices from domestic and overseas show that the deterioration of reinforced concrete structures caused by poor durability of concrete,especially poor anti-chloride penetrative performance of concrete,has caused great damage to social production.On the other hand,substituting granulated blast-furnace slag(GBS)for natural sand of concrete raw material can not only effectively use of GBS produced in steel industry,but also improve the present situation of natural sand resource scarcity.The relevant research results from domestic and overseas show that the concrete using GBS as fine aggregate is similar to natural sand concrete in physical and mechanical properties,freezing resistance performance and drying shrinkage properties.However,there are few research and reports about anti-chloride penetrative performance of concrete using GBS as fine aggregate.In summary,the experimental research about anti-chloride penetrative performance of concrete using GBS as fine aggregate has great realistic meanings.In this experimental research,GBS,natural sand or a mixture of GBS and natural sand(equal volume)are used for fine aggregate of concrete with five different water cement ratios,and the anti-chloride penetrative performance of concrete was tested by the electric flux method.In addition,taking into account the excitation of latent hydraulic property of GBS may affect anti-chloride penetrative performance of concrete after a longer period of time,an extension test was conducted on the basis of the specifications,and the anti-chloride penetrative performance of concrete with 90 d or 180 d curing period was measured respectively.Meanwhile,on the basis of the above research contents,in-depth studies have been carried out through SEM,energy spectrum analysis,transfer theory of chloride ion in concrete and research results about concrete using GBS as fine aggregate.Research results show that the lower water cement ratio and the higher anti-chloride penetrative performance of concrete whatever concrete using GBS or natural sand as fine aggregate,in addition,using GBS as fine aggregate or increasing replacement of GBS for sand ratio can improve anti-chloride penetrative performance of concrete with different water cement ratio or curing period.At the same time,the similar results can be obtained by SEM experiments,energy spectrum analysis,etc.