ULTRA HIGH PERFORMANCE FIBER REINFORCED CONCRETE USED IN NAGPUR FLYOVER
AAMIR SOHAIL SHAMIM AHMAD
Chapter No-01
INTRODUCTION
Technological advancement was made in the concrete field within the past two centuries. With the advent of chemical additives, a producer of concrete can influence the setting time, slump, and even air entrainment of a mix. For example, the use of super plasticizers (SP), which are also known as high range water reducers (HRWRs), can make concrete flow and consolidate due to its own self-weight. Other options, apart from the use of chemical admixtures, are available as well.
Concrete's weight can be reduced or enhanced with a change in aggregates. Lightweight
aggregates may be necessary for specific applications. The use of such aggregates can reduce the unit weight of concrete, making slabs and wall sections thinner.
Heavyweight concrete containing steel and iron aggregates can create a unit weight in excess of 300 pounds per cubic foot. Such concrete is useful in nuclear reactor walls . Even though strength is always a concern as architects, engineers are pushing the boundaries of design continually with bridges that span longer distance, and with taller buildings. With these advanced, the concrete must be stronger, more flexible, and more durable.
The concrete industry for many years were aiming to develop high performance materials that can sustain the server environments. Attempts and efforts were made on maximizing the ultimate strength of the cement-based material besides the durability, which are the main important properties of the concrete based on design standpoint. These efforts were completed by producing a new class of portland cement-based material, which is known as Ultra-High Performance Concrete (UHPC). With this new technology, High-Performance Concrete (HPC) is no longer the strongest and most durable material properties compared to UHPC.
