Experimental Study On The Effect Of Inducer On Oyster Adhesion Mechanism On Concrete Surface And Concrete Performance

The corrosion of reinforced concrete in the marine environment has become one of the issues that people are increasingly concerned about.The large amount of chloride ions contained in the seawater penetrates into the surface of the steel bar and rusted steel bars are the main reason for the destruction of the reinforced concrete structures in the marine environment.At present,the anti-corrosion measures of marine concrete projects are generally for the splash zone,and concrete engineering in the tidal zone are difficult to maintain due to the particular environmental conditions.Recent studies have shown that membranes formed by sessile organisms,such as oysters attached to the surface of concrete structures in tidal zone,can effectively prevent chloride ions from penetrating into the concrete.In this paper,the mechanism of concrete induced oyster adhesion and properties of concrete were studied.Based on ensuring that the compressive strength and chloride ion permeability of concrete are not affected,the effect of inducer on the adhesion on concrete surface were studied and the permeability concrete samples attached with oyster were tested.The main research content is as follows:Acordding to the preference of marine sessile organisms for attaching substrates,T and M inducers were incorporated into common concrete used in marine engineering to optimize the concrete mix ratio,and 17 sets of concrete mix ratios were designed.Compressive strength and impermeability tests of concrete were performed at different ages.The test results showed that the strength of concrete with T-inducing agent at early age had a downward trend,and that with M-inducing agent was slightly increased.The incorporation of T-inducing agent had an adverse effect on the impermeability of concrete at early age,and the incorporation of M inducer improved.When adding T inducer and M inducer,the impermeability of the concrete is better than that of the single inducing agent.The concrete specimens containing different inducer and content were hung for oyster attachment test in the Yellow Sea.The results showed that the two inducers could promote the attachment of the oysters on the concrete surface,and the oyster attachment induced by the M inducer is better than that of the T induction agent.The oyster attachment of concrete incorporated with two kinds of inducers was much better than that of concrete with single inducer.When adding 5%T inducer and 9%M inducer,the oysters adhered to the concrete surface were densest.Concrete drill core was sampled and capillary water absorption was performed after concrete samples experienced 240 d exposed experiment in marine enviroment.The results showed that the oysters attached to the concrete surface significantly improved the impermeability of the concrete,and the higher the oyster coverage,the higher the impermeability of the concrete.The influence of oyster attachment on the surface concrete pore structure of exposed concrete specimens was investigated by mercury porosimetry.The results showed that the more oysters on the surface,the surface porosity of the concrete lower.