Technical Narrative: This proposed workshop, organized by the South Dakota School of Mines and Technology, and Istanbul Technical University, is scheduled for 09 May 1992 in Istanbul, Turkey. The workshop objective is to discuss the future needs and future directions of U.S-Turkey collaborative research on the use of cementitious materials in concrete. This workshop will follow the Fourth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete to be held 03-08 May 1992 in Istanbul. This proposal supports the travel of approximately eight U.S. engineers who will participate in the workshop and also present papers at the conference. This workshop to plan future collaborative research activities involving construction materials fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Turkey to combine complementary talents and pool research resources in areas of strong mutual interest and competence.