Chapter 5: Chip Seals

5.0 Field Testing

Most tests of constructed chip seals are empirical and indicate what extra adjustments must be made on the job site.  Though not used by Caltrans, The Ball Penetrometer Test (7) and the Sand Patch Test (ASTM E965) are useful methods for checking the original pavement and the final seal.  In the Ball Penetrometer Test, a Marshall hammer is used to pound a ball into the pavement surface a predetermined number of times.  The depth of ball penetration into the existing surface is an indicator of the pavement’s hardness with typical values ranging from 0 to 0.5 mm.  The Sand Patch Test gives surface texture information for classifying surface type or examining seals with typical texture depths ranging from 1 mm to 2.5 mm depending on the aggregate size.  Figure 16 illustrates a technician performing the Ball Penetrometer Test and the Sand Patch Test.

a) Ball Penetrometer Test

b) Sand Patch Test

Figure 16: Field Test Methods