This document addresses materials and quality considerations when using cast-in-place, normal-weight, high-strength concrete in structures that must be designed for moderate to high seismic applications. The term "high-strength concrete," as defined by ACI Committee 363, refers to concrete having a specified compressive strength for design of 8000 psi (55 MPa) or greater. The lower 6000 psi (41 MPa) threshold, however, was chosen for the ITG-4 document because it deals with a specialized application of high-strength concrete application in areas of moderate to high seismicity. An accompanying standard, ITG-4.1 (available Spring 2007), is written in mandatory language in a format that can be adopted by local jurisdictions, and will allow building officials to approve the use of high-strength concrete on projects that are being constructed under the provisions of ACI 301 and 318. ITG-4.2R is the supporting document for that standard. ITG 4 has also developed another non-mandatory language document: ITG-4.3R (available Spring 2007). It addresses structural design and detailing considerations.