الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Within the past few years, there has been a phenomenal increase in the development of concrete with compressive strength in excess of 70 MPa and up to 120 MPa. This concrete has been consistently utilized in bridges and high-rise buildings, and it was referred to as high-strength concrete (HSq. However, the use of HSC has gradually shifted from the emphasis on its compressive strength to other superior properties of the materials, such as high workability, high density, high elastic modulus, and long-term durability. Durability of this concrete is defined by its low permeability, resistance to weathering action, chemical attack, abrasion, or any other process of deterioration. These properties make it relevant to call it ”Quality Concrete”. The later is designed to perform well throughout the design life of structure. Such a quality concrete is referred to as ”High- Performance Concrete (HPC)”. The tenn high-performance concrete (HPC) was first introduced for concrete mixtures possessing three main characteristics, namely; high workability, high strength, and high durability. Therefore, the primary distinction between HPC and HSC is the imperative requirement of high durability and high workability in case ofHPC. (I)
Typically, HPC has a water-cernentitious material ratio (w/c) of 0.4 or less. Therefore, the achievement of HPC frequently depends on the effective use of superplasticizer (SP) to ensure high workability, which is one of the common characteristics ofHPC mixes. Due to the low w/c, the strength of HPC is typically higher than the strength of conventional concrete. However, the high strength is not always the primary requirement. In fact, in many applications where concrete suffers from some forms of attacks, durability rather than strength is the primary consideration. Marine concrete structures and bridges are examples of such applications. In other applications, such as high-rise buildings both strength and durability must be given due importance. In long span bridges, the primary considerations may also include high elastic modulus of concrete. Concrete permeability is a critical requirement when chlorides are present.