Phosphogypsum-Based Concrete: Engineering Characteristics And Road Construction Application

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)


Civil and Architectural Engineering


In this study the engineering characteristics of concrete mixtures containing dihydrate phosphogypsum, a by-product of the wet phosphoric acid industry, is investigated. Phosphogypsum-based concrete mixtures consolidated by impact compaction, external high-frequency vibration or static compaction are studied in unconfined compression, splitting tension and bending, and the results are expressed as functions of the constituent materials. Factors affecting the fundamental engineering properties such as, moisture at the time of testing, curing conditions, mixing procedures, and specimen sizes are also considered. The construction of various field compacted phosphogypsum concrete slabs, including a full scale plain and fiber reinforced phosphogypsum-based concrete ramp, are presented. Strength results obtained from both field and laboratory specimens are later compared. Finally, a thickness design for a selected phosphogypsum concrete rigid pavement is discussed.Laboratory test results conclude that, with proper proportioning and consolidation methods, the dihydrate phosphogypsum can be used as a binding aggregate in concrete mixtures and its presence can improve the strength characteristics. The encouraging results obtained from field compacted slabs confirm the effective utilization of this waste-product in the construction of rigid highway pavements.


Engineering, Civil

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