These recommendations apply only to structures using normalweight concrete with a compressive strength fc? not exceeding 15@000 psi (100 MPa) in the connections. From consideration of recent research results of connections with concrete compressive strengths of up to 15@000 psi (100 MPa)@ ACI Committee 352 has extended the limits of the recommendations to include high-strength concrete (Guimaraes@ Kreger@ and Jirsa 1992; Saqan and Kreger 1998; Sugano et al. 1991). The committee believes that further research demonstrating the performance and design requirements of connections with lightweight-aggregate concrete is required before the scope of these recommendations can extend beyond normalweight concrete. These recommendations are applicable to structures in which mechanical splices are used@ provided that the mechanical splices meet the requirements of Section 21.2.6 of ACI 318-02 and the recommendations of the Commentary to Section 21.2.6 of ACI 318-02.??