沥青与集料粘附性试验新方法

A New Experimental Method of Adhesion between Asphalt and Aggregate

目的开发新的试验方法实现定量化评价沥青与集料的粘附性能.方法室内将集料置入一定质量浓度的沥青-甲苯溶液中,采用分光光度计测定溶液吸光度的变化并计算其初始吸附沥青量;再向溶液中加入蒸馏水,经过一定试验时间计算其净吸附沥青量以评价其受水剥离的程度.结果将5种类型的沥青和4种花岗岩集料的试验结果与水煮法试验结果相比较,得出集料粘附等级（由初始吸附量和净吸附量计算的剥落率）其关系为：5级（0~10%）、4级（10%~30%）、3级（30%~50%）、2级（50%~70%）、1级（70%~100%）.结论采用沥青—甲苯溶液质量浓度的改变来表征沥青与集料的粘附性能试验方法更客观,对于水煮试验无法判断的粘附性能细微差别,可以做出定量的判断,该方法试验敏感性强,可作为准确鉴别沥青与集料粘附性的试验方法.

A new experimental method was developed to evaluate quantitatively adhesion between asphalt and aggregate. The aggregate was put in a concentration of asphalt - toluene solution and the variety of its absorbance was determined using a spectrophotometer. Thus the amount of bitumen initially adsorbed onto the aggregate surface was obtained. Several hours later distilled water was added to the solution, the amount of bitumen remaining on the aggregate can be calculated to evaluate aggregate＇s stripping potential. The five sources of asphalt binders and four sources of granite aggregates were tested under the laboratory testing program. The relation between adhesion grade and stripping percent （ which was calculated from the amount of bitumen initially adsorbed and the amount of bitumen remaining on the aggregate）is：fifth grade（0 - 10% ）, fourth grade（ 10% - 30% ）, third grade （ 30% - 50% ）, second grade （ 50% - 70% ）, first grade （ 70% 100% ）. In comparison with water boiling method, the experimental method which was characterized by a change of the concentration of asphalt-toluene solution was more objective and sensitive. As an experimental method,it can determine quantitatively a subtle difference of adhesion between asphalt and aggregate.