Effect of PVA fiber in increasing mechanical strength on paste containing glass powder

This paper presents some experimental results related to mechanical properties of fibrous concrete with polyvinyl alcohol (PVA) fiber application. The use of fibers in paste is to improve the performance of concrete as well as increasing the ductility of concrete. The mix proportion of paste was varied into 17 basic paste without fiber. Glass powder as silica source was used as cement replacement from 0-25% by cement weight. The powder was replaced by silica fume which varied from 0-60% by glass powder weight. Five compositions with the highest strength at 28 days and one composition of variable control (100% cement) were selected to make fibrous pastes with additional PVA fibers. Low water to the binder ratio of 25% was applied to all the mixture. Material and mechanical analysis were conducted for material reactivity, mineral composition, porosity, compressive and tensile strength. Replacement of cement with glass powder and silica fume produced the highest compressive strength of 93.26 MPa at 28 days. The highest compressive strength of fibrous paste of 99.85 MPa showed that fiber can increase the paste strength. It was also proved that application of glass powder and silica fume increased the tensile strength up to 27.22%. With the addition of PVA fibers, split tensile strength pastes increased almost 200% from original split tensile of bare paste without fiber. However, the addition of PVA fibers decreased the workability and increased the porosity of matrix.