Using Tubular Sections in Structural Composites

Project Brief

Located in Bholi, a Village in Khandala Taluka in Satara District of Maharashtra State, India the Office and Skill Development Center for Suhana Masala. It is located 55 KM towards North from District headquarters Satara. The building is designed as an architecturally pleasing space with large span slabs without beams for areas such as Swagat Kaksh. The building is part of a larger Industrial sheds catering to production facilities for the final product, Masale.

Choice of Materials

Reinforced Concrete and Structural Steel (primarily tubular) has been used extensively for the construction Office and Skill Development Center with form finished concrete Cantilevered Box Walls, offices, Lifts and kitchen areas. Structural tubular sections have been used as composite sections for large span slabs and cantilever viewing decks.

Architectural Details

The Office and Skill Development Center is a commentary on the shed typology of industrial architecture. Although large in scale the building is full of smaller nuances that can be experienced by the user. Cascading pitched roofs house programs like the exhibition space (Swagat Kaksh) which has large span slabs without any beams and office spaces that are large volumes in height, to more intimate spaces like that of a lunchroom and verandahs. The building opens up to a landscape full of trees with their crowns almost entering the building through its large fenestrations.


The primary challenge in the design was to have large span beamless Swagat Kaksh 8m x 21m  with form finished concrete. As the spans increase the slab depth and deflection increases and the actual concept of having beamless clean slab would become unviable. The challenge was also for the bottom of slab should be same for adjacent areas such as Entrance lobby etc. No false ceiling was designed to have been erected later hence both the top and bottom of the slab had to match the other adjacent area levels.

It was decided to use Tata Structura tubular sections with concrete slab of grade M40 with Self compacting concrete. A grid of RHS 150x150x8 was used in the internal parts of slab with studs on both faces to tie with the reinforcement of the slab. A total thickness of 260mm was designed to keep the top and bottom clear cover. The saving due voids in the tubular sections would account for reduced dead weight and overall saving in the thickness of the slab with no internal beams.

Value engineering is required by MEP services to improve upon existing traditional systems of conduiting to pass through the tubes rather than laying additional layers of conduits which when design properly is far better than traditional method.


In Conclusion

Using steel tubular sections as composites in RCC structural systems is a way forward for optimized architectural space design coupled with improved ductile behavior, stiffness and deflections. While structural composite sections have been used extensively in Bridges in India, the need to use composite sections with tubular sections has several advantages in terms of sleeker building profiles and internal space usage. The improved seismic behavior of the structure is an added advantage.

Fact File

Client: Suhana Masala. Architect: Samira Rathod, Samira Rathod Design Atelier

Structural Design: Sushil Singh, StudioStruct

Contractor: Bhate & Raje Construction Company Pvt Ltd.

Tubular Steel Supplier: Tata Structura, Tata Steel

Leave a Reply

Your email address will not be published. Required fields are marked *