GURUGRAM: Indian Institute of Technology (IIT), Mumbai, has handed over its
report on the
slab collapse at
Hero Honda Chowk
flyover in April to NHAI. Prepared by professor Alok Goyal, department of civil engineering,
IIT, Mumbai, it said, “The photograph of damage indicates severe deficiency in the strength of the
concrete slab.”
Submitted in June, the report hinted that even though the issue was local, such problems might occur in other parts of the flyover and it would be difficult to identify those parts in advance. However, it added, “No immediate action is required in other parts of the bridge.”
An RTI filed by Aseem Takyar had sought the details of the report. Takyar said, “The RTI has revealed that the concrete slab, which fell in April, was weak. The IIT report also tells us that such problems cannot be ruled out at other parts of the flyover.”
A chunk of concrete fell off the Delhi-bound flank of the flyover in April. At the time, Valecha Engineer Limited, the contractor of the flyover which is in charge of its maintenance, had done a patchwork to cover up the crater.
NHAI confirmed that the issue was local. “As the damage was due to localised concrete distress, Valecha renovated the deck by removing concrete slabs of size of 3.2x5.8m and replacing them with M50-grade concrete (reinforced concrete segments),” said a senior NHAI official, adding, “No other type of damage has been noticed on the flyover. The entire structure is safe.”
However, according to the IIT report, “The failed part of the deck slab was locally repaired with high strength concrete without additional reinforcement... However, the repaired part of concrete needs to be supported from below till the hardening of the new concrete. Additionally, regular monitoring of the repaired area is recommended.”
