Taiwan, with a population of over 21 million and situated within only 36,000 sq km of land, has achieved miraculous economic growth in the last 20 years. This economic achievement has transformed the national image from one of underdeveloped work force to that of a global economic power. The mass volume of concrete construction which has occurred during the transition period has resulted in the near exhaustion of natural resources such as limestone, river gravel, and river sand. Diminishing supplies of limestone for the manufacture of cement and aggregate for making concrete have resulted in serious shortages over the last four years. In response to the crisis, the Architecture and Building Research Institute (ABRI) of the Ministry of Interior initiated a research program in 1991 to investigate all concrete-related industries in the private sector. A team of six professors and ten graduate students from five prominent universities were asked to examine these problems and to draft a national strategy to resolve the crisis at hand. The program was completed in June, 1992 and the final report is being used to guide the process of bolstering the domestic concrete industry. This aper presents an overview of current problems existing in the concrete related industries, methods used in investigations, and suggested topics for current and future research. The proposed research programs were subsequently divided into three term stages with the objective of avoiding possible delays with the on-going Six-Year National Construction Plan and laying down a sound foundation for the development of high performance concrete (HPC) technologies in Taiwan. With the support from governmental agencies, high performance concrete has been successfully used in the construction of a few major highway bridges and an 85- story high-rise building that is currently under construction in Kao-Hsiung, the second largest city in Taiwan.

A consortium of six companies and two governmental research funding organizations are carrying out a six-year research and development program on high performance concrete in Sweden. In mid-94, half the program time was completed. The program focused on research directed towards the understanding of mechanisms and subsequent modeling and experimental verification. It also included application and oriented research aiming at the establishment of technical relationships. This should further lead to practical recommendations and guidance for use in specific projects or product and process development within the industry. The program was divided into 17 different subprojects that were grouped under the headings of materials, production technique, and structures. The fields of research were selected following an evaluation of the possibilities offered by dense, low w/c ratio cementitious systems in improving performance, but at the same time the potential risks when using these systems were addressed. An evaluation on possible application areas resulted in the study of certain aspects of structural behavior. The research was carried out at eight different research entities in Sweden as well as by research and development personnel from the consortium participants. The work was done in laboratories as well as in situ.

In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University. The paper includes the results with regard to the mix design, uni- and triaxial strength, creep, shrinkage, and chloride diffusion of HPC. The paper further gives a brief description of the bridge structures in Denmark in which HPC has been utilized. These structures include pedestrian bridges, highway bridges, and major infrastructure schemes such as the Great Belt Link and the Oresund Link. Finally, the paper states the research areas which, according to the experiences in Denmark, should be investigated in the future in order to improve HPC. These areas include the strength loss of silica fume concretes, workability, ductility, and confinement problems.

This paper presents a summary of a four-year research program sponsored by the Strategic Highway Research Program under contract C-205. The program included plain and fiber reinforced concrete. This paper summarizes the results of plain concrete. The paper covers the literature search and review, the development of mixture proportions of three categories of high performance concrete, the laboratory studies and field trials of the concretes. An assessment is made of how the research met its objectives and the limitations of the research are pointed out. Finally, the paper is concluded with a list of future research needs.

Practical use of high-strength concrete in Norway has shown that it is susceptible to cracking at early ages and that it normally is subjected to high curing temperatures due to high cement contents. The paper summarizes the results of a number of investigations at The Norwegian Institute of Technology and SINTEF research institute, both in Trondheim, Norway. The topics are: (1) early volume changes in the binder phase and early cracking sensitivity of high-performance concrete; and (2) the consequences of elevated curing temperatures on pore structure characteristics, permeability to chloride, and frost resistance of high- performance concrete.