Cast In Place Permanent Ferrocement Formwork For Concrete Beams And Columns
This study presents the viability of using ferrocement technology as a cast in place permanent form for concrete beams and columns. The new system consists of four phases; the preliminary phase where a modified reinforcement design of beam and column is processed, design phase where design parameters are set, construction phase and the application phase where possible loads are determined and then materials used are tested. A 0.485 water-cement and 1:2.75 cement-sand ratios respectively are used for the mortar mix and a ½ x ½ gauge 23 galvanized welded wire mesh for reinforcement. Construction phase includes the load testing of the fabricated 200mm x 300mm x 10mm prototype ferrocement plates using a Universal Testing Machine (UTM) and 100mm x 200mm x 2400m beam samples using Reaction Frame Test (RFT). Ferrocement form prototype has a nominal capacity of 0.015kN-m creating 0.02mm deformation while achieved during the actual test which has an impressive average capacity of 0.267kN-m for a deflection of 0.02mm, thus makes the design form applicable. A modified beam with 4-1 x 1 x ⅛ angle bars and has a capacity of 20.23kN-m and is comparable to a conventional beam with 4-12mmØ deformed rebars that has a capacity of 14.32kN-m. The comparative analysis shows a 31% cheaper cost in materials compared to conventional formwork without re-using materials and 9% cheaper costs when materials are used twice. The labor needed for the new system almost equalled to that estimated for conventional system when materials are used twice with only 4 to 5 percent savings. The new system is time efficient with 11 to 17percent savings in number of days as compared to using conventional formwork systems. The analyzed data shows that ferrocement as formwork is viable and has achieved the necessary requirements a good formwork must have. Furthermore, economic efficiency of this study goes beyond what is expected; granted that the new system is done in considering the project in its entirety.
Keywords- Alternative Formwork, Concrete Design, Ferrocement, Formwork System