JODHPUR, Sept. 16 -- The new Rajasthan high court building in Jodhpur is showing signs of early-age deterioration of reinforced concrete, with corrosion of reinforcement identified as the principal mechanism behind the distress, according to the final structural rehabilitation report prepared by experts from IIT Bombay. The report attributed the deterioration to a combination of carbonation, doubtful concrete quality, localised chloride contamination and moisture ingress. It said the building can be repaired and its structural strength restored, but warned that nearly 40% of the building requires urgent or immediate attention. The experts, however, did not identify an intermediate overall collapse risk to the central dome. They said the risk of concrete spalling warranted immediate access control, systematic tapping and monitoring, followed by time-bound rehabilitation. The report said that concrete quality was not uniform throughout the building and some localised areas had concrete below M20, possibly because of cracking associated with ongoing corrosion. The assessment also found problems with concrete compaction and surface hardness. The experts said rebound hammer and ultrasonic pulse velocity tests indicated that the concrete was not well compacted and had developed a porous nature. They also observed that the concrete was not sufficiently monolithic with the reinforcement, making it susceptible to spalling. Corrosion was found to be active throughout the structure. Half-cell testing indicated an 80% high risk and 20% uncertain risk of active corrosion in the reinforcement. Moist areas showed corrosion and exposed reinforcement, while corrosion progressed more slowly in dry areas. The experts noted that the corrosion risk was broadly similar in spalled and unspalled areas. The report also found chloride contamination in the concrete. The average chloride content was 0.73 kg per cubic metre, equivalent to about 1.43% by weight of cement when calculated against a minimum cement content of 350 kg per cubic metre. At some locations, however, chloride content exceeded 4.5% by weight of cement, indicating highly corrosive concrete. The report said the risk would increase when such concrete comes into contact with moisture. Carbonation was identified as the major concern beyond chloride contamination....