1512 Definition of HPC

Until now, it is not possible to provide a unique definition ofHPC without considering the performance requirements of the intended use of the concrete. Generally, HPC can be defined as a concrete composed of the same raw materials as normal concrete with additional admixtures and engineered to achieve enhanced workability, durability, or strength characteristics to meet the specific demands of a construction project. Hence, any concrete that satisfies certain criteria proposed to overcome limitations of conventional concretes may be called HPC.

In addition to various definitions given by different concrete researchers, many very respected insti-tutitons have regulated the definitions according to their experiences and requirements. Some good examples are given in the following list:

1. Definition from Strategic Highway Research Program. Based on the results of SHRP C-205, Zia et al. [5] summarized the requirements for HPC as shown in Table 15.1. It should be noted that the requirements include strength, w/b ratio, and durability factor.

TABLE 15.1 Definition of HPC According to SHRP C-205

Category of HPC

Minimum compressive strength

Maximum water/cement Minimum frost ratio durability factor

Very early strength (VES)

Option A (with Type III cement)

Option B (with PBC-XT cement)

High early strength (HES) (with Type III cement)

Very high strength (VHS) (with Type I cement)

2,000 psi (14 MPa) in 6 h 2,500 psi (17.5 MPa) in 4 h 5,000 psi (17.5 MPa) in 24 h 10,000 psi (70 MPa) in 28 h

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