Ultra-High Performance Concrete (UHPC) INTRODUCTION
UHPC is a class of concrete defined by its exceptionally high flexural and compressive strength. UHPC was first developed in the early 1980’s and since then has been used for applications needing exceptional strength and durability like nuclear power plants, thin-profile bridges, structural beams and seawall anchor plates.UHPC derives its high performance from a carefully calibrated ratio of engineered ingredients and a mixing sequence that packs molecules closely together to create very tight bonds. The high packing density yields excellent flexural, compressive, and impact strength. Because the molecules are so tightly packed, the capillary pores that exist in traditional concrete are eliminated.
The basic raw materials of UHPC are concrete, water, sand, cement, silica fume, and plasticizers. However, UHPC is an order of magnitude different from traditional categories of concrete. No special resins, cellulose, or polymers are used to achieve the outstanding properties of architectural UHPC. Rather, the distinction lies in the size, geometry, and carefully selected chemistry of extremely small particles that combine under exacting mixing, vibration, and curing regimens to form a base matrix.
This new advanced cementitious material; the UHPC has opened the door to many potential applications and proved to be a viable solution for improving the sustainability of architecture.
Although UHPC is higher in production cost, it would be more realistic to look at the costs on the basis of the entire project. Due to its high strength one is able to use panels that are smaller in cross sectional area (slender and light structural or façade components) thus leading to savings in prestressing and reinforcing steel.
UHPC has good workability, low creep and shrinkage losses, and high wearing resistance. Its excellent durability results in longevity of structures and a reduction in overall maintenance or repair costs.
UHPC posses ceramic properties such as impermeability to water, heat resistant, and surface behaviors making it ideal for usage in high strength applications.