沥青碎石混合料毛体积密度测定方法的改进

分析了大孔隙沥青碎石混合料毛体积密度的测定方法，指出了蜡封法和体积法的不足，对蜡封法作了改进，并通过试验研究对其进行了对比分析。分析结果表明，蜡封法计算的孔隙率平均值为5．45％，基本不透水的，而体积法计算的孔隙率平均值为29．54％，孔隙率对水几乎无阻力，蜡封法和体积法对于半开级配沥青碎石混合料密度测定均不适宜，而用改进的蜡封法测定的试件孔隙率平均值为11．32％，孔隙率变异系数最小，比较稳定，是一种较好的办法。改进的蜡封法能够阻止蜡液进入试件内部孔隙，因而测定的试件体积比蜡封法和体积法准确，且理论上也趋于合理。

Modification of the Method for Testing Bulk Density of Asphalt Macadam with Large Void Ratio

The methods for testing density of asphalt macadam with large void ratio are analyzed, the defect of wax sealing method and volume method are also discussed, these two methods were just the ones recommended by specifications for testing bulk density of asphalt macadam, and the method of wax sealing is modified. Some experiments are also conducted to analyze the modified method. Void ratio got by the method of wax sealing is about 5.45%, and void ratio got by the method of volume is about 29.54%, while void ratio got by the modified method is about 11.32%, the coefficient of variation of void ratio is also minimum.The results indicate that the two methods recommended by specifications are not suitable for testing bulk density of asphalt macadam, and modified method is better than the two methods.The modified method can prevent wax liquid from going into specimens interior, so specimens volume got by it is accurate in contrast with other methods. The modified method is demonstrated reasonably and stable by the verification experiments.