About the Author: Mr. Hasan is a registered professional engineer with 40 years plus experience in civil design and construction management of nuclear, hydroelectric, water resources and infrastructure projects. His responsibilities included preparation of construction specifications for concrete, support during construction, design and control of concrete mixtures for various regions in the USA and overseas, rehabilitation of concrete dams, spillways, and canal structures, surveillance, instrumentation, and thermal monitoring, preparation and review of quality assurance/quality control procedures, contact grouting of steel and concrete lined tunnels, inspection and trouble-shooting reports, expert witness on concrete technology, condition survey and inspection of dams and spillways. He has published over a dozen technical papers and articles on concrete technology and participated in international conferences on concrete durability. Currently, he is a member of American Concrete Institute and ASTM technical committees, and a Fellow of American Society of Civil Engineers.