Test: Highway Materials, Construction & Maintenance - Civil Engineering (CE) MCQ

In CBR test the value of CBR is calculated at both 2.5 mm and 5.0 mm penetration, Normally the CBR value at 2.5 mm penetration which is higher than that at 5.0 mm is reported as the CBR value of the material.

Minimum ductility value of a normal bitumen should be greater than 50 cm.

The cutback with the lowest viscosity is designated by numeral 0, such as RC-0, MC-0 and SC-0, suffix numerals 0, 1, 2, 3, 4 and 5 designate progressively thicker or more viscous cutbacks as the numbers increase. This number indicates a definite viscosity irrespective of the type of cutback; in other words, RC-2, MC-2 and SC-2 all have the same initial viscosity.

The penetration test determines the hardness or softness of bitumen by measuring the depth in tenths of a millimetre to which a standard loaded needle will penetrate vertically in five seconds. The sample is maintained at a temperature of 25°C.

A bitumen emulsion is liquid product in which a substantial amount of bitumen is suspended in a finely divided condition in an aqueous medium and stabilized by means of one more suitable materials. The function of this emulsifier is to form a protective coating around the globules of binder resisting the coalescence of the globules.