SP128 Leading world experts met in Hong Kong to participate in The ACI conference on Evaluation and Rehabilitation of Concrete Structures and Innovations and Design. The specific purpose of the Conference was to disseminate technical information on emerging concrete technology in the Pacific rim region. You can review the results of that timely event in a two volume document comprised of 90 technical papers. Volume I contains paper dealing with materials. Topics include: high elastic surface coatings, concrete deterioration on high chloride and sulfate environment, nondestructive testing, impact-echo technique, fiber reinforcement, injectable cementitious materials, and case studies. Volume II is comprised of papers pertaining to design aspects. Topics include: concrete for offshore structures, performance of structural repairs, design of high-strength and reinforced concrete structures, design of beams and columns, and case studies.order.

A 17-story reinforced concrete structure with prestressed concrete floor slab, clad with an architecturally pleasing white cement and calcined stone aggregate, exhibited signs of deterioration after 30 years exposure to central London environment. The investigation was instigated after a piece of concrete spalled from a high level and crashed down. After the investigation, when the cause of the deterioration was established, recommendations were made to the client and specifications for repair were made. After the repair specialist was selected the author supervised the repair ensuring that the specifications were strictly followed. The paper describes the investigations and the rehabilitation of the structure.

During the mid-1970s, there was a boom in the construction industry in Saudi Arabia. To meet the housing requirements, and to furnish the infrastructure needed for a growing industry, construction had to be carried out at a pace unprecedented in the country's history. In the absence of guidelines, concrete specifications from other industrialized countries were used. However, when the structures started to show signs of deterioration within a short fraction of their design life, it was realized that specifications developed for temperate conditions cannot be used in this region. Field and laboratory studies carried out at King Fahd University of Petroleum and Minerals at Dhahran, Saudi Arabia, showed that concrete in this region should not only be designed for strength, but also for durability. Since permeability is one of the most important properties that control the durability of concrete, much emphasis should be given to the production of dense and impermeable concrete. This paper reports the results of an investigation carried out on a number of reinforced concrete structures exposed to underground and seawater conditions that showed serious signs of deterioration within less than 10 years after construction. The paper recommends repair procedures for the damaged structures and future practices to extend their service life.

Mr. Landau graduated from Harvard Business School and held positions of major responsibility in the textile field in Germany, Belgium, Canada and the United States. With a background in the global fiber industry, specializing in polypropylene since 1971 Landau introduced the U.S. product, Fibermesh, into the world-wide construction market. Since 1983, he has traveled extensively developing a sales and engineering organization supplying polypropylene fibers for use in concrete. Landau has participated as a speaker in many National and several International Conferences, including the July, 1984 Conference in Rio de Janeiro, Brazil, Rilem Conference in Sheffield, England in July, 1985, XIII Bienniel Conference in Brisbane, Australia, 1987, and the Concrete Society Conference in Hong Kong, July 1987.

A general introduction is followed by justification of the need for and benefits of evaluation of service life of structures. It is argued that, since decisions on the part of promoters and designers are made in the environment of uncertainty, deterministic approaches are misleading. A probabilistic approach, in the form of a combination of Monte Carlo simulation and microcomputers, is recommended for its ability to address the challenge adequately and conveniently. Case studies are used to illustrate the value of the methodology through its ability to evaluate service life and costs, thereby acting as an efficient tool for aiding selection of the efficient alternative from available alternative designs and maintenance policies. The sensitivity analysis, which is an integral part of the methodology and can be applied at both the modelling and the input parameter stages, serves to point out the critical factors or issues involved and should be valuable to practitioners and researchers. An interactive and tolerant program, VENTURER is available, which places the expertise of the probabilistic analysis at the fingertips of the professionals, even if they are not familiar with statistics.