International Concrete Abstracts Portal

Many recent innovations in advanced concrete materials technology have made it possible to produce concrete with exceptional performance characteristics. High Performance Concrete (HPC) is defined as concrete which meets special performance and uniformity requirements that cannot always be achieved by using only the conventional materials and normal mixing, placing and curing practices. The performance requirements may involve enhancements of: placement and compaction without segregation, long-term mechanical properties, early-age strength, toughness, volume stability, or service life in servere environments. International Workshop on High Performance Concrete addresses technical papers presented during the workshop. A total of 32 papers are included and cover subjects including: * Self-compactable high-performance concrete in Japan * Durability of DSP mortars exposed to conditions of wetting and drying * Ferrocement: Applications for urban environment * Studies of high-performance concrete structural members * High performance and durability through design * United States government's role in high-performance materials for infrastructure * Tensile properties of high-performance concrete * High-performance concretes for highway applications * Bending properties of high early strength fiber reinforced concrete * High-strength concrete research for buildings and bridges 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. SP159

Australia is a dry warm continent. The major population centres are located close to the coastline. This paper examines the predictions for future building and construction activity in Australia. Based on the physical situation, for example climate and geography, and the anticipated needs for HPC arising from the forecast trends in construction activity it tries to forecast the research needs for HPC in Australia. It also endeavours to assign priorities for these research needs in terms of the size of the market likely to be affected.

Although the cement-paste matrix is intrinsically protective to steel, it also permits the ingress of deleterious agents that leads to its own progressive deterioration and consequent destabilisation of steel. Further, the development of a highly impermeable cement matrix, per se, may not ensure a high- performance concrete structure in practice, since the development of strength and pore structure are both time-dependent phenomena and aggressive elements somehow find a means of penetrating concrete and initiate a cumulative process of structural damage. This paper advocates an integrated design philosophy from concept to completion and during service life of a concrete structure. It is shown that by selecting concrete constituents that encourage synergic interactions, it is possible to develop a concrete matrix of high strength and excellent durability. However, concrete also needs to be protected from aggressive agents to enable it to attain its full potential and examples are given to show how such techniques can be adopted to ensure durable service life even in the most unfriendly environment. The application of this integrated design strategy is further illustrated with the design of columns exposed to alkali-silica reactivity and the production of cost-effective, fiber-reinforced thin sheets.

Technology transfer within the construction industry is difficult due to (1) organization of the industry, (2) lack of construction industry participation in research, (3) societal impediments. These barriers are discussed in relation to transferring innovation to practice. Differing activities that can mitigate the barriers are discussed and recommendations are offered to enhance the transfer of technology from research results to application in the construction industry.

This paper discusses recent research on high performance concrete with a focus on cemenentitious materials designed for durability. A major key to suchp erformance originates with the concrete microstructure. Recent advances in optimizing cement and concrete materials by using calculated packing diagrams offer the promise of superior products achieved by increased packing efficiency. A high packing density coupled with adequate processing and cement binder characteristics makes possible the formation of a fine microstructure. In turn, this fine microstructure results in a low permeability and therefore provides a resistance to aggressive forces from the environment, which together enhance its long term durability. The favorable interaction among physical and chemical phenomena gives rise to better long term performance, whether the application is structural, or chemical, such as in waste management.