EXTRUDED FIBER-REINFORCED CEMENT PRESSURE PIPE

Extrusion is a plastic-forming method that is suitable not only for fl at shapes, but also for structural shapes, such as I-sections, channel s, pipes, and hollow and solid tubes. The advantage of introducing ext rusion 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 extrud ed fiber reinforced cement pipe and flat sheet. A pipe die was designe d and developed specifically for extrusion of cement based materials. Three different mix proportions were selected by varying the fiber typ e (polyvinyl alcohol and alkali-resistant glass), admixture type (sili ca 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 bur st strength, bearing strength, and flexural performance. Thin sheets w ere tested for tensile and flexural performance. The test results indi cated 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.