With the help steam curing technology, NCRTC is ensuring that the pace of construction of the tunnel rings is maintained despite the changing weather and construction of the RRTS corridor continues to progress at a pace. As the newly constructed segments automatically gain early strength in higher temperatures, this technique is not required in summer.
Defying the severe cold wave condition in the northern region, construction of the Delhi-Ghaziabad-Meerut RRTS (Regional Rapid Transit System) corridor is still progressing at a rapid pace with the use of a special technique.
The northern part of India is experiencing an unprecedented cold wave, which has slowed down construction works in the region.However, with special steam curing techniques, even the falling temperature ceases to slow the rapid construction in the underground section of RRTS.
Precast segments of the tunnel rings, used for the construction of the underground section of the corridor, are being manufactured at a pace with the help of ‘Steam Curing Technology’ at the casting yard of NCRTC(National Capital Region Transport Corporation).
A joint venture company of the Government of India and the states of Haryana, Rajasthan, Uttar Pradesh, and Delhi, NCRTC is mandated with implementing RRTS projects across the National Capital Region (NCR)
Tunnel segments are being cast at the casting yard of NCRTC with assured quality control. However, with the onset of winter, the task of precasting the segments faced a challenge.
Due to low temperatures, the segments moulded by the machines do not get early strength in the stipulated time frame. That is, the concrete, bars, and other construction materials used in the segment do not reach their definite solid state on time.
The segments must be completely solid and strong with the required strength to be used in tunnel construction. Therefore, NCRTC uses the steam curing technique to strengthen and solidify precast segments in low-temperature climates rapidly.
Under the steam curing technique, the newly formed segments are steamed for 5 to 7 hours with the help of a boiler. This allows the newly formed segments to solidify in their concrete structure and gain early strength almost three times faster.
Typically, when the temperature is below 10 degrees, it takes a normal precast segment about 40 to 45 hours to solidify. However, the steam curing technique completes the same work in about 10 hours.
With the help of this technology, NCRTC is ensuring that the pace of construction of the tunnel rings is maintained despite the changing weather and construction of the RRTS corridor continues to progress at a pace. As the newly constructed segments automatically gain early strength in higher temperatures, this technique is not required in summer.
In the underground section in Delhi, the construction of two parallel tunnels of about 3 km in length from Anand Vihar station towards New Ashok Nagar and about 2 km towards Sahibabad is in full swing.
For the construction of these two parallel tunnels, four Sudarshan are constructing about 10 km of tunnel, out of which more than five and a half km of tunnel construction has been completed.
About 25,600 tunnel precast segments have been used so far in Delhi.
In Meerut, out of the 11 km parallel tunnel that needs to be constructed, close to 5 km has already been built, and about 21,000 tunnel precast segments have been used. These tunnel rings are manufactured at the casting yard of NCRTC with assured quality control.
NCRTC has been using precast segments for construction since the inception of the project. Precasting helps in the safe and speedy execution of construction work while ensuring better quality control and reducing air pollution and noise pollution. The decision to adopt precasting technology was an important strategic decision.
NCRTC aims to open the entire Delhi-Ghaziabad-Meerut corridor to the general public by 2025. Before this, the 17-km long Priority Section between Sahibabad to Duhai of the Ghaziabad region will be operationalised this year for the public.