International Concrete Abstracts Portal

The purpose of this symposium and special publication is to recognize and honor Professor Amin Ghali’s outstanding long-term dedication to the concrete industry. Dr. Ghali obtained his B.Sc. and M.Sc. degrees in Civil Engineering from Cairo University, Cairo, Egypt, respectively in 1950 and 1954, his Ph.D. from Leeds University, England in 1957. He spent ten years in engineering practice before joining at the University of Calgary, AB, Canada as a professor in 1966. Dr. Ghali has developed the revolutionary, multi-patented and globally used, headed-stud shear reinforcement systems for concrete flat slabs; he has been a consultant for a number of major international structures, including offshore structures, multi-story buildings, bridges, and tanks. Dr. Ghali authored over 300 papers and eight patents. In 15 editions and 6 translations, his books include: Structural Analysis Fundamentals (2022), Structural Analysis: A Unified Classical and Matrix Approach (2017), Circular Storage Tanks and Silos (2014), and Concrete Structures: Stresses and Deformations (2012). Professor Ghali has served the industry in many ways, including his role as a voting member of ACI Committee 435, Deflection of Concrete Building Structures, 343, Concrete Bridge Design, and 421, Design of Reinforced Concrete Slabs. Jointly with associates at University of Calgary, his research on punching shear design and control of long-term deflection enables design of affordable concrete floors. Dr. Ghali served as expert, providing technical testimony, for a number of complicated engineering cases. Dr. Ghali received a number of teaching and research excellence awards over his long career, and was elected a Fellow of ACI, ASCE, CSCE, and CAE; in 2017, he received the Top 7 Over 70 Award for his outstanding continued research and engineering contributions. The papers found in this SP publication encompass a broad overview on the important issues related to punching shear resistance and sustainable serviceability of flat plates from both a theoretical and design perspectives. These papers formed the basis of presentations made at the Amin Ghali Symposium on Design of Structural Concrete Slabs for Safety Against Punching and Excessive Deflection held at the ACI Fall 2020 Virtual Convention, on October 25, 2020. Twelve presentations were made in two sessions by those who have worked closely with Dr. Ghali in his areas of interest. The SP includes nine papers on design of concrete floors for punching and for serviceability. The sessions were sponsored by ACI Committee 421, Design of Reinforced Concrete Slabs. All papers in this publication were reviewed by at least two recognized experts in accordance with ACI review procedures. Special thanks are extended to all who helped to make the two technical sessions and accompanying publication a success.

During 1994, a new 50,000 m 2 warehouse and similar area of external pavement was constructed at Ingleburn near Sydney, Australia. The client required that the warehouse meet very onerous performance criteria that required the construction of a very flat, prestressed concrete floor that would be crack free, with excellent abrasion resistance, and having a minimal number of joints. The design required that the concrete base provide the wearing surface for the floor without application of a surface topping. A second industrial project which required the construction of high performance concrete floors is a new integrated printing facility for a major newspaper, commenced at Chullora near Sydney in late 1994. The plant is highly automated; sections of the floor are designed to be frequently loaded with turning transporters carrying full rolls of newsprint. Such floors require exceptional abrasion resistance. The designers decided to seek a level of abrasion resistance even higher than that provided at Ingleburn. To minimize joints and cracking, the concretes were designed to have 56- day drying shrinkage of less than 450 microstrain and to exhibit an abrasion resistance, when tested in situ using the Chaplin abrasion machine, of less than 0.10-mm depth of wear. This marks the first time such a direct measurement of abrasion resistance has been specified and assessed in Australia. Key elements of both projects were the high performance concrete floors, which were required to meet tolerances on surface flatness ¦ 2 mm on 3-m straight-edge and ¦ 4 mm overall. These and other strict performance criteria were met consistently during construction providing clients with world class low maintenance warehouses.

Using a case study, describes how to correctly use ACI Committee 302, "Guide for Concrete Floor and Slab Construction," to select the appropriate criteria for specifying a Class 5 concrete floor. Provides a set of guidelines for selecting and meeting the specification.