Behavior Of FRP Confined Simulated Sea Sand Concrete Short Columns

At present,the world's construction areas are facing the crisis of freshwater river sand supply,the development of sea sand resources is imperative.As a necessary fine aggregate material to concrete,the use of sea sand resources must eliminate the chloride ion and sulfate ions,they will bring an adverse effect on the durability of metal materials and cement material.Commonly used fresh water cleaning method is expensive,but also the secondary pollution caused by the environment.And the addition of rust inhibitor will have a potential impact on the strength and durability of concrete.As a new composite material,FRP has been widely used in industrial and civil construction areas recently.It has a light weight,high strength performnce and corrosion resistance.In this regard,this article finds another way,the sand and FRP material complementary advantages,the combination of research.A series of 156 cylindrical short cylindrical specimens were prepared by mixing a series of simulated sea sand with linearity in the same ratio.The samples were confined with 1 layer BFRP,2 BFRP,1 Layer CFRP,28 days after molding for axial pressure performance test,the quantitative controllable research and analysis.Specifically studied the following:The failure modes of the specimen under different confinement conditions are analyzed,and the failure modes of the specimen are analyzed.The influence of the FRP material type and the number of the coating layers on the bearing capacity and ductility of the short columns is studied.The results showed that:1 parcel layer BFRP to enhance the ultimate bearing capacity of concrete short is not large,but the ductility of specimens received considerable extent.FRP confined with different strength concrete short column,the lower the strength of concrete strength to enhance the rate but larger.The ultimate load carrying capacity and ductility of the two layers of BFRP with one layer of CFRP are similar to those of the CFRP.Under consideration of self-weight and cost,consider the use of one or more layers of BFRP instead of CFRP.At the same time,Teng et al's 2009 design model,Jiang and Teng 2007 analysis model had been used to predict the test results,and predict the stress-strain curve and the test curve were compared to further analyze the test results,it shows that wrapped FRP on the sea sand concrete short column mechanical properties have a good upgrade.The feasibility of simulating sea sand by immersion method was verified by detecting the ion content in simulated sea sand.The results show that the content of ions in the sea sand and the effect of the type on the concrete strength are analyzed.The results show that the total content of chloride and sulfate ions in the sand lead a lower the strength.The research results of this paper have far-reaching significance for the development of sea sand resources and the combination of sea sand and FRP materials.