Extruded fiber reinforced cement pressure pipe

Extrusion is a plastic-forming method that is suitable not only for flat shapes, but also for structural shapes, such as I-sections, channels, pipes, and hollow and solid tubes. The advantage of introducing extrusion into cement product processing is that the materials are formed under high shear and compressive forces resulting in composites with improved performance. This article presents research results on extruded fiber reinforced cement pipe and flat sheet. A pipe die was designed and developed specifically for extrusion of cement based materials. Three different mix proportions were selected by varying the fiber type (polyvinyl alcohol and alkali-resistant glass), admixture type (silica fume, metakaolin, and latex), and their proportions to study their influence on the properties of extruded fiber reinforced cement pipes and thin sheets. Extruded cement pipes were tested for hydrostatic burst strength, bearing strength, and flexural performance. Thin sheets were tested for tensile and flexural performance. The test results indicated that polyvinyl alcohol fibers in the presence of silica fume and latex provide a suitable reinforcing effect, and silica sand provides good surface finish. (C) 1998 Elsevier Science Ltd.