Experimental Study On The X-ray Nondestructive Density Test For Road Asphalt Concrete

Compaction degree is an important index of road construction quality inspection.There are a lot of detection techniques in road engineering.Cutting ring,sand filling method and water bag method etc.are destructive detection.These methods not only have time-consuming,slow speed,small amount of information,but also destroy the original road structures.Ground penetrating radar,rayleigh wave method and transient spectrum density analysis method etc.are nondestructive testing.Among them,the nuclear densimeter is radioactive and must be strictly protected.Otherwise,the radioactive material will cause some damage to the testers.X-Ray density measurement is a fast,accurate and easy to operate nondestructive testing method,but it is rarely used in the field of road material density measurement.In this paper,X light source,CZT semiconductor single crystal radiation detector are used to detect the density of asphalt concrete specimens of Marshall.We also studythe Marshall specimen density and the relationship between X-ray absorption dose by three different detection methods like the single probe head type,double probeslevel-type and double probes relative-type.The results show that when the X-ray light source voltage is lower than 160 kV and the radiation time is less than 3 minutes,the X-ray is used to test the Marshall specimen,there are scattered and irregular phenomenon of test data.While the voltage is higher than 160 kV and the radiation time is more than 3 minutes,5 different density Marshall specimens are tested by the double probes relative-type,there is a good corresponding relationship between the density and the absorption of X-ray dose.The results provide a theoretical basis for the application of X-ray in the field of road material density measurement.