Phosphogypsum As A Building Material: Strength Characteristics And Housing Application

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)


Civil and Architectural Engineering


The mechanical behavior of new composites containing phosphogypsum, by-product of the wet phosphoric acid industry, in its raw and calcined form respectively, is investigated. Phosphogypsum-cement-sand based mixtures placed by high-frequency vibration or static compaction are studied in unconfined compression, indirect (splitting) tension and bending, and the results are interpreted as functions of the constituent materials. Effects of moisture content at time of testing and curing conditions are also considered. Phosphogypsum calcination using microwave and convection ovens is investigated with particular attention to free and crystal water removal. The unconfined compressive strength of the materials obtained with both heating techniques is then compared.Finally, the construction of a modular building unit, made of precast ferrocement sandwich panels assembled with cast-in-place joints, is presented. The phosphogypsum content of the matrix is 50% by weight. Panels behavior in bending and edge-wise compression, and solid connections performance are also studied by comparing the experimental data with the values derived from the non-linear reinforced concrete theory.


Engineering, Civil

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