A Method of Rapid Compactness Inspection for Cement Stabilized Macadam

Abstract

In order to realize the rapid compactness inspection of cement stabilized macadam (CSM), a detector for the compactness of CSM was developed based on the instantaneous impulsion method. Acceleration response value (ARV) was used to evaluate the CSM compactness. Four different gaskets were applied to reduce the effect of the uneven surface of CSM on the detection of ARV. The ARV of the unhardened CSM specimens with different compactness was measured by the detector. Firstly, the correlation coefficient of compactness and ARV was calculated to determine the optimum type of gasket in order to let the detector initially distinguishes the compactness of CSM. Secondly, the influence of hammer weight and falling distance between the correlation coefficient and the effective depth was studied. The results of tests indicate that the correlation of compactness and ARV is high using the gasket DP-4 with falling distance of 40cm and hammer weight of 5.7kg, and the correlation coefficient reaches 0.9675. The fitting formula of compactness (x) and ARV (y) is y=24.429x-2040.8. Compared with falling distance, hammer weight has greater impact on the correlation coefficient.