Hot Sand Test

The hot sand test for the adhesivity of binder on pre-coated chippings is a laboratory testing method that is used to evaluate the bond strength between a binder material, such as asphalt or bitumen, and pre-coated chippings, which are small pieces of aggregate that have been coated with a thin layer of the binder material. The test is specified in the European standard BS EN 13043, which covers the use of pre-coated chippings for the construction of roads and other surface layers.

During the test, a sample of pre-coated chippings is placed in a bed of sand that is heated to a specified temperature. The temperature of the sand is then increased at a controlled rate, and the bond between the binder and the chippings is evaluated by measuring the force required to break the bond. The results of the test are typically expressed in terms of the bond strength, which is the force required to break the bond divided by the surface area of the chippings.

The hot sand test is typically used to evaluate the performance of pre-coated chippings under conditions of thermal stress, which can occur when the chippings are used in asphalt or other surface layers that are subjected to high temperatures. The results of the test can be used to predict the long-term performance of the chippings in service and to select materials that are suitable for specific construction applications.