Which base codes are used alongside IS 3201 for capacity design?

IS 456 is used for reinforced concrete design and IS 1343 is used for prestressed concrete components.

How are handling stresses accounted for during lifting?

By applying an impact or dynamic factor to the self-weight of the element during lifting and transport, depending on the lifting equipment used.

What specific load condition is critical for lightweight precast roofs?

Wind uplift is often a critical load case for purlins and truss tie-down connections, requiring careful anchorage detailing.

IS 3201

: 1988

Criteria for design and construction of precast trusses and purlins

CurrentSpecializedCode of PracticeBIMStructural Engineering · Planning, Housing and Pre-fabricated Construction

Download PDF BIS Portal Google

This standard provides the criteria for the design, manufacture, handling, and erection of precast reinforced and prestressed concrete trusses and purlins, commonly used in industrial sheds and large-span roofing systems.

Criteria for design and construction of precast trusses and purlins

Quick Reference Values

Minimum bearing length for purlins100 mm

Impact factor for handling and erection1.5 to 2.0 (applied to dead load)

Maximum deflection for purlinsSpan / 250

Minimum clear cover for precast members20 mm (as per standard RC exposure)

Practical Notes

Handling and erection stresses often govern the design of precast elements; lifting points must be precisely calculated, detailed, and marked on the physical elements.

Connections between precast trusses and columns must be carefully detailed to safely transfer lateral loads like wind uplift and seismic forces.

Precast purlins must be checked for bending moments in both principal axes, especially on sloping roof trusses.