International Concrete Abstracts Portal

The increase in the number of high-rise reinforced concrete buildings has accelerated the research on the manufacturing and development of high strength materials. Ministry of Construction, Japanese Government, organized a national research project from 1988 to 1993 for “the Development of Advanced Reinforced Concrete Buildings using High-strength Concrete and Reinforcement.” This paper introduces the earthquake resistant design guidelines developed as a part of this technical project. The scope is limited to the building height of 200 m, the concrete strength of 60 MPa, and the steel strength of 700 MPa.

An overview is presented of New Zealand applications and design concepts for the utilization of high strength concrete (concrete compressive strength greater than 55 MPa (8,000 psi)) in various forms of structures that are required to withstand seismic loading. In order to take advantage of the high concrete compressive strengths and enhanced durability designers and researchers are investigating various structural applications. The performance of elements of these structures ranges from remaining elastic during a major seismic event through to being required to exhibit significant ductility in the major events.

The changes to the seismic design provisions of the revised New Zealand concrete design standard, NZS 3101:1995, for beam-column joints to allow for high strength concrete are outlined. The changes include bond equations for bars passing through beam-column joints to take into account concrete strength and other factors, and new shear equations for the design of horizontal and vertical shear reinforcement. The results of simulated seismic load tests conducted on one-way interior beam-column joints constructed of normal and high strength concrete with concrete compressive cylinder strengths ranging between 31 and 61 MPa are also briefly described. The changes to the revised standard and the tests indicate that there are advantages in using high strength concrete in moment resisting frames.

This paper discusses briefly, the major applications of high-strength concrete in seismic regions. The advancement of material technology and production has led to higher grades of concrete strengths. These concretes can be produced using conventional production procedures, The use of high-strength concrete is becoming popular in the USA and other countries. The reduced member sizes obtained through the use of high-strength concrete will develop reduced inertial loads under seismic excitation. Strength and ductility are the most important design considerations for a structure to behave satisfactorily under these conditions. These aspects relevant to high-strength concrete members are summarised in the paper.

In May of 1993, approximately twenty researchers and five representatives from construction firms met in Kyoto, Japan, for the First Multilateral Meeting on Structural Performance of High-Strength Concrete in Seismic Regions. Four countries (United States, Japan, New Zealand, and Australia) were representated at the meeting. The 3-day meeting divided into eight sessions covering current research programs and applications of high-strength concrete in the respective countries. The objectives of the meeting were to exchange information and to develop a coordinated program for further information exchange, evaluation of information, and development of design guidelines for the use of high-strength concrete in seismic regions. The follow-up meeting was held in November 1994 in Honolulu, Hawaii, and was attended by twenty seven participants from the US, Japan, Canada, New Zealand and Hong Kong. The Second Multilateral Meeting on Structural Performance of High-Strength Concrete in Seismic Regions consisted of thirteen sessions. Six of the sessions concentrated on the following behavioral topics: bond and anchorage, confinement, flexural members, axially-loaded members (columns and walls), beam-column joints, and shear and torsion. An additional session was devoted to presentation and discussion of design concepts and applications of high-strength concrete (HSC) in seismic regions. The remaining six sessions consisted of large and small working group sessions. During the small group sessions, participants were divided into groups of five to ten members to discuss the results of the previous sessions. Summaries of the small working group were then presented to the entire group fro additional comments and conclusion during the large working group sessions. This ACI Symposium Publication comprises selected papers which were the outcome of the Second Multilateral Meeting on Structural Performance of High-Strength Concrete in Seismic Regions. The working group discussion summaries are also included in this special publication. The editors are appreciative of the eforts of the authors and reviewers of these papers. The cooperation of the authors in the careful revision of their papers in accordance with the reviewers' comments is greatly appreciated. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP176