Browsing by Author "Kashi, Mohsen Gholam-Reza"

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    Freeze-thaw durability of high strength silica fume concrete
    Kashi, Mohsen Gholam-Reza (Virginia Polytechnic Institute and State University, 1988)
    Specimens from 27 batches of concrete with water to cementitious (cement plus silica fume) ratio of 0.25 to 0.32, with and without entrained air, were tested for freeze-thaw durability in accordance with ASTM C666, procedure A (freezing and thawing in water). In addition, another set of similar specimens were moist cured for 28 days instead of 14 days and tested in accordance with ASTM C666 , Procedure A to determine the effect of curing time on the freeze-thaw durability of high strength concrete. Results show that non air-entrained high strength concrete with water cementitious ratio of less than 0.30, regardless of the length of curing time, is frost resistant. Non-air-entrained concrete with water-cement ratio of 0.32 is also durable if silica fume is not used.
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    A performance analysis of the hi-plan structural apparatus
    Kashi, Mohsen Gholam-Reza (Virginia Polytechnic Institute and State University, 1985)
    Visual experience is a powerful pedagogic tool. Extensive use of experimental studies prior to design and construction has made conceptualization of complex structures possible. Experiments on reduced-scale structures and specimens are also vital tools for teaching structural mechanics. As such, the Department of Civil Engineering at Virginia Tech has acquired a new apparatus for use as an educational demonstration tool in the area of structural mechanics. This work presents the results of a detailed study on the performance of this device as related to its accuracy and operation. To fulfill such objectives, two structural models (a continuous beam and a portal frame) were extensively tested under several loading and support configurations. The models were analysed using STRUDL as well as a computer program developed by the author. The comparison of the results (deformations) obtained in the two phases of the study have indicated that the apparatus is reasonably accurate to meet the requirements of a structural teaching model and adapting to a variety of structural models.