Selection of Treatments for Each Condition

52 is to correct deficiencies caused by distresses and to protect the pavement from further damage. Various degrees or levels of maintenance can be applied to all pavements, regardless of the end use. A condition rating of the pavement will help determine what pavement maintenance technique is necessary Lavin, 2003. Figure 2.21 shows nine renewal activities which restore the condition of pavement from a downstream condition worse to an upstream condition better Akyildiz, 2008. Two type of maintenance that routine and preventive maintenance are the most economical options. Reconstruction techniques are the most expensive, and are usually done when there is no other choice. Although not shown in Figure 4.11 , there are times in the life of a pavement when the best alternative is to do nothing. This is usually when the pavement is not a candidate for maintenance, and rehabilitation or reconstruction is not yet justifiable David, 2006. 53 Very Good condition 5 Good Condition 4 Fair Condition 3 Poor Condition 2 Very poor Condition 1 Reconstruction Rehabilitation 1 Rehabilitation 2 Thick overlay 3 1 Thin overlay 4 1 Thin overlay 3 1 Thick overlay 2 1 OM 3 OM 4 Fig 2.21 pavement condition maintenance activities Akyildiz, 2008 54 Definition of Sets a. Pavement Condition: This set represents the pavement’s condition state. There are 5 predefined pavement condition states available. These condition states are as follows Akyildiz, 2008. 1. Very Poor Condition 2. Poor Condition 3. Fair Condition 4. Good Condition 5. Good Condition

b. Set of Treatments: A set of treatments represents the treatment types to be used

in the model. There are 9 predefined treatment types available. These treatments and their definitions are as follows Akyildiz, 2008: 1- Reconstruction applied to pavement in very poor condition: This treatment type restores pavement in very poor condition to excellent condition. 2- Rehabilitation 1 applied to pavement in very poor condition: This treatment type restores pavement in very poor condition to good condition. 3- Rehabilitation 2 applied to pavement in poor condition: This treatment type restores pavement in poor condition to excellent condition. 4- Thick Overlay 2 applied to pavement in poor condition: This treatment type restores pavement in poor condition to good condition. 5- Thick Overlay 3 applied to pavement in fair condition: This treatment type restores pavement in fair condition to excellent condition. 6- Thin Overlay 3 applied to pavement in fair condition: This treatment type restores pavement in fair condition to good condition. 7- Thin Overlay 4 applied to pavement in good condition: This treatment type restores pavement in good condition to excellent condition. 55 8- Ordinary Maintenance OM3 applied to pavement in fair condition: This treatment type preserves pavement in fair condition. 9- Ordinary Maintenance OM4 applied to pavement in good condition: This treatment type preserves pavement in good condition.