Radar Detection Feature Of Reinforced Concrete And Research On Dielectric Constant Of Radiation Shielding Concrete

It is focused to take advantage of kinds of medium technology to monitorstructural health states. Ground penetrating radar, i.e. GPR, an emerging andadvanced non-destruction technique developed in recent years, based on sensitiveelectromagnetic property of materials, with a number of advantages of higherresolution, faster speed, stronger, non-contact and deeper penetration, no pollutionand no radiation, has been applied widely more and more in various fields in civilengineering. The research details in the paper are as following:(1) Make three concrete specimens: one with rebars with the same diameter indifferent depth, one with rebars in the same depth with different diameter, one withdefects such as voids, uncompacted gravel and foreign matters. Use the radar to detectthe structure to identify corresponding image feature after related data processing, sothat the results can provide evaluation basis for NDT of concrete internal states;(2) Design three ordinary concrete specimens with different water content, andof which aggregates are pebble and rubble respectively. After detection from5-56days, it is found that the dielectric constant is most heavily affected by water contentof per unit, and varies as curing period.(3)Design three radiation shield concrete specimens with different water content,and of which aggregates are barite, magnetite and hematite respectively. Afterdetection from5-56days, it is found that the dielectric constant has the similarvarying pattern, but its value is higher than ordinary concrete ones.(4)Via comparative analysis of the detection results of the floor thickness and itscover of reinforcement by GPR and thickness gauge as well as rebar locator, it proves that GPR detect more precise, which meet the engineering demand.