Experimental Study On Flow Behavior,Strength And Chloride Diffusion Characteristics Of Fly Ash Based Self Compacting Concrete

The durability of the concrete structure is a key problem in ocean engineering.Corrosion of steel bars in concrete seriously influences the safety of concrete structures.It is generally accepted that chloride diffusion in concrete structure is the basic source of corrosion of steel bars in concrete.Many concrete structures are constructed near the maritime environment.But these structures are extra vulnerable to chloride attack.Another hand,the usage of self compacting concrete is getting fame in construction engineering.Therefore,to improve the cost and performance of self compacted concrete is the most important task in construction activities.By using different types of admixtures and fine minerals,the performance of self compacted concrete can be improved.Furthermore,the utilization of more quantity of cement in the construction industry is very harmful to our environment.To resolve this problem,one alternative manner is a replacement of cement with waste materials such as fly ash in self compacting concrete.The major benefits of using these types of waste products are trying to improve the durability and mechanical properties of the concrete structure.In order to prove the possibility and operability of this theory in practice,this article carried out an experimental study.This experimental work is mostly dedicated to study the flow behavior,mechanical properties,and chloride diffusion characteristics of fly ash based self compacting concrete.The current study was carried out to find a suitable mix design having significant resistance against chloride attack with satisfactory flow behavior.Total 14 concrete mixe design made by considering different water-cement ratios,fly ash mass fraction,and coarse aggregate volume.Concretes in 11 cases are self compacting concrete,and concretes in the remaining three cases are normal concrete for comparison purposes.To analyze the performance of these mixes compressive strength,flow characteristics,and rapid chloride migration test performed to check their mechanical and anti-chloride properties.Previous research has focused on the impact of coarse aggregate volume ratio,fly ash mass fraction,and water to cement ratio on the mechanical properties of SCC.But the research work related to the influence of these parameters on the anti-chloride properties of SCC is limited.Therefore the present study attempts to bridge this gap by experimentally,analysis an effect of these parameters on different properties of SCC,especially for anti-chloride properties under the ocean environment.During the flow test,it is observed that fly ash has a positive influence on the flow characteristics of the concrete mixes.By increasing fly ash mass fraction in concrete mixes,the slump flow length of these mixes increases.The flow characteristics also increase with the increment of the water-cement ratio of the mixes.Flow characteristics of the concrete mix based on coarse aggregate volume decrease by increasing the coarse aggregate volume in concrete mixes.However,the compressive strength of these mixes decreases by increasing fly ash mass fraction and water-cement ratio.The compressive strength of these mixes significantly improves by increasing coarse aggregate volume.During,the investigation of anti-chloride properties of concrete mixes,it is noticed that the addition of fly ash into concrete mixes enhances the chloride resistance of concrete mixture.Also,the addition of coarse aggregate volume in concrete mixes within certain limits increases the chloride penetration resistance of the mixture.