ANS: There are mainly two methods of pavement evalution

Structural Evalution of pavement :

• The structural evalution of rigid and flexible pavement can be analysed by conducting plate bearing test.. The structural capacity of the pavement is studied by the load carried at a specified deflectin of the plate.

• Field investigation and tests have shown the performance of a flexible pavement related to the elastic deflection under load.

Functional evalution of pavements :

In functional evalution of pavement, the surface condition of flexible pavement can be evaluated by the ruts, patches, cracks and unevenness, whereas, the surface condition of rigid pavement can be evaluated by the faulty joints and cracks developed.

The pavement unevenness can be measured by following instruments :

1. Unevenness indicator

2. Profilograph

3. Roughometer or profilometer

Pavement riding qualities are expressed in terms of unevenness index recommendedby Hpllaway given in table. Unevenness index,cm/km Riding quality In old pavements
1) Below 35 Excellent 2) 95 to 119 Good 3)120 to 144 Fair 4)145 to 240 Poor 5)Above 240 Very poor

In New pavements
1) Below 120 Good 2) 120 to 145 Fair 3) Above 145 Poor