Abaca Fiber Reinforced Phosphogypsum Concrete Panels (modulus Of Rupture, Toughness, Splitting Tensile Strength)

Date of Award




Degree Name

Doctor of Arts (D.A.)


Civil and Architectural Engineering


In this experimental study the possibilities of utilization of phosphogypsum--industrial waste--in concrete, reinforced with abaca vegetable fibers, were investigated. Effects of varying the abaca fiber content and the phosphogypsum content on flexural, tensile and compressive strengths and ductility of concrete were examined. The flexural behavior of abaca fiber reinforced phosphogypsum concrete panels was studied extensively and compared with gypsum wall board, used commercially as an interior wall panel.Panels and cylinders were cast by using sixteen different concrete mixes which were prepared by changing the amount of four variables: fiber, phosphogypsum, water, and panel thickness. Specimens were tested in bending, tension, and compression. Fiber content ranged from 0.0 percent to 0.8 percent. Phosphogypsum content was varied from 0.0 percent to 75.0 percent. Water/(Cement + Phosphogypsum) ratio was varied from 0.46 to 0.60. Thickness of panels tested was 3/8 in., 1/2 in., and 5/8 in.Test results indicate that phosphogypsum can be used in concrete as a fine aggregate. High strength capacity can be obtained when phosphogypsum in a mix is less than 50 percent of the total solid weight. Phosphogypsum increases the water demand for a workable mix. It reduces the unit weight of concrete.It is concluded that the combination of two materials, phosphogypsum and abaca fibers, in the production of thin concrete wall panels, gives successful results. Phosphogypsum provides good finishing and strength and abaca fibers provide the necessary pseudo-ductility for wall panels. Test results also showed that the phosphogypsum concrete panels were much stronger than gypsum wall-board.


Engineering, Civil

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