Routine inspection under this category, general inspections are carried out quickly and frequently by highway maintenance engineers having reasonably practical knowledge of highway structures through not necessarily experts in design.
Detailed inspection: This type of inspection can be furr divided as general and major depending upon frequency and extent of inspection.
Special inspection: Special inspection is resorted to under extraordinary situations such as earthquakes, high intensity/ abnormal loading, floods etc.

The super structure of Obra singrauli bridge located on eastern railway in India comprises of 4 numbers of 18.3m spans and one number of 24.4m span and decking is made up of two prestressed concrete girders stressed with Freyssinet system of post tensioning and after 15 years of service prestressed girders developed large number of cracks at junction of girder and deck slab on both internal and external faces.

Normally a work cycle of one week is required for casting and launching segments and to allow super structure to move forward, special low friction sliding bearings are provided at top of various piers with proper lateral guides and main problem is to ensure safety of stresses in super structure under its own self weight during all stages of launching at various critical sections.

The following three types of sealants are generally used depending upon ir suitability in given situation: Mastics are asphalts with a low melting point with added fillers or fibers and y are recommended where total movements will not exceed 15 percent of width of groove, Thermoplastics comprising of asphalts, pitches and coal tar become liquid or semi viscous when heated and groove depth to width ratio should 1:1 and total design movement is of order of 25 percent of groove width and Elastomers include a wide range of materials such as poly sulphides, epoxy poly sulphides, poly urethane, silicones and acrylics and se materials advantages since y can be used without heating.

In this methods preload is applied prior to repair of damaged concrete and removed after completion of repairs and a metal sleeve jacket is installed around and beyond damaged area and gap between metal sleeve girders is filles with epoxy grout by pressure injection.

A wide variety of electronic equipment is presently available in market in many countries for monitoring and inspection of distress in different types of structures and ultrasonic meters are used to determine degree of deterioration and distress and / or material imperfections that are relevant to structural integrity of structure to be inspected and pachometer is used to locate steel reinforcements and measures sizes of bars embedded in concrete to an accuracy of 3m.

Pretreatment of concrete surface is generally carried out by sand blasting, shotcrete blasting, grinding or roughening with pneumatic needle gun or granulating hammer and grain structure of concrete must be exposed before steel plates are fixed.

In cast in situ method at least a week?s time is required to move formwork to next incremental length and precast segment system, units can be bought to site and lifted by cranes to join m to previous units by using temporary stressing cables and rate of construction will be faster in precast method than in cast in situ method and in both methods a typical cross section would be a box girder of constant or variable depth.

The adhesive joint is generally between 1-3mm thick and tests have shown that tensile shear strength of adhesive is initially proportional to square root of thickness however tensile shear strength reaches a maximum and n starts decreasing as adhesive thickness is furr increased and hence thinner layers prove stronger and have greater resistance than thick ones.

The structural concrete slab panels and beams exhibiting distress can be repaired by external bonding of steel plates to soffit by using epoxy adhesives and hollows, honey combs and cavities in concrete can be repaired by process of guniting and shortcreting applied pneumatically with impact force.