The Pavement Voids Test Based On PXI And SCXI Architecture

With the increase of service time of existing cement concrete pavements when it is in using, various diseases have occurred for many existing cement concrete pavements. One of the principal diseases is void beneath cement concrete slabs. If the void scopes extend gradually, cement concrete slabs will appear cracks and then reduce to crash. So, if there void beneath cement concrete slab, it is significant for the pavement rehabilitation to find a method to determine the size of void area. Practice has proved that, under the semi-grouting sealing is an effective treatment method, but the prerequisite is depending on accurate to the position of the voids correctly , otherwise the results would be counterproductive.At present, there are many non-destructive testing is used in the voids in the pavements ,such as acoustic shock, ultrasonic wave, radar, deflection test and so on, and this paper introduce the vibration test technology which base on the acceleration signals. The different structure of cement concrete pavement results in different resonant pattern, According to this you can calculate and determinate the condition of void which in the cement concrete pavement. From the processing and analysis of the vibration signal, you can make certain the law of the occur and development of the flow, and to determine the location of defects.For hidden and hazardous voids of the cement concrete road surface condition, the vibration acceleration signal is used for test and condition characteristics determine. The incentive acceleration signals shocked by a drop hammer are actually collected using the hardware architecture which composed by NI PXI-6070E card and SCXI-1531 signal condition card. The collected signal is analyzed through the frequency domain analysis and feature extraction, the gotten result of signal processing can be used to determine whether there is void condition, and from the result can calculate the size of space sold and serious situation. The actual experiment and the result of the experiment shows that it is easy and effective to test the engineering application of the cement concrete road surface void condition with the use of PXI and SCXI structure of the virtual instrument test platform.