HYDERABAD: IIT-Hyderabad has developed an affordable Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) for bridge and other infrastructure applications.
Prof S Suriya Prakash, CASTCON Lab, Department of Civil Engineering, and his research group developed the affordable special UHPFRC using locally available materials like cement, fly-ash, river sand, ground granulated blast furnace slag, micro-silica, water, steel fibre, polypropylene fibres and high range water reducing agent (HRWRA).
The cost of UHPFRC was brought down and made affordable by reducing the quantity of cement, fibres and replacing costly fine aggregates with cheaper locally available ones through proper gradation. The composition combines the best features of self-consolidating concrete (SCC), fibre-reinforced concrete (FRC) and high-performance concrete (HPC).
The cost of UHPFRC developed at IIT-H is about two times cheaper than commercially available proprietary products. UHPFRC developed at IIT-H for pre-stressing applications yields a cube compressive strength of 150 MPa and a direct tensile strength of 8.0 MPa.Several full-scale post-tensioned UHPFRC concrete bridge girders were tested to understand the shear behaviour.
Test results show that providing a minimum web shear reinforcement ratio and adequate steel fibre dosage leads to better serviceability, ultimate strength, and stiffness of bridge girders.
The overall cost of UHPFRC girders in bridge applications can be further reduced by providing the minimum web-shear reinforcement of 0.6 per cent and a hybrid fibre volume dosage of about 1.0 per cent
Enlisting the uniqueness of the UHPFRC, Prof S Suriya Prakash, CASTCON Lab, and Chandrashekhar Lakavath, Research Scholar, Dept of Civil Engineering, IIT-H, said:
“The aim is to develop an affordable ultra-high-performance concrete using locally available materials and do a thorough material categorization to understand the behaviour of UHPFRC in compression, tension, fracture, and direct shear. Several full-scale bridge girders made of UHPFRC were tested.”