Influence of water-cement, polymer-cement and fiber-cement ratios on properties of fiber reinfroced mortars

Mortars are one of the very important construction material to build safe buildings, bridges, barrages and new constructions. Because of its importance and its huge usage area, they are frequently researched by universities and by firms. There is also need for further modification and analysis of mortars to develop this material for future applications and according to needs of humans. This study focuses on influence of different ratios of water-cement, polymer-cement and fiber-cement ratios, hybrid fibers on mortars. Due to this aim a mathematical model is evaluated. To create mathematical model surface respond method has been used. As a design of experiment, central composite design has been used. Fiber type and polymer type are selected constant during mathematical model. Only 12mm glass fiber and acrylic-styrene copolymer resin has been used. The proportions of polymer-cement, fiber-cement and water-cement ratios are evaluated according to central composite design. There is an important advantage to use surface respond method in the experiments. In the end of experiments, the results can be defined as mathematical equations and it is possible to estimate the whole results in the range of design of experiments without making further experiments for unselected values. Out of mathematical model, there are three group of polymer modified hybrid fibered mortar produced. In hybrid fibered mortars combination of polypropylene-12 mm glass fiber, polyamide-12 mm glass fiber and 3mm Cem-FIL glass fiber are evaluated. Additionally, one group has been produced with 6mm surface treated glass fiber. To find out the trade-off between effect of polymers, different type of and different amount of fibers and also the effect of combination of fibers, flexural, compressive and slump tests are performed. Slump tests are performed after the mixing of fresh mortar. Due to using slump values, viscosity and processability of mortar have been understand. After production of mortar specimens, they are waited 2 days in water pool and totally 60 days are waited. Because of the polymer content, the cure time is restricted to 2 days. After production, after water cure and before testing the specimens, their weight are calculated and noted to see their weight change up to time. The magnitude of specimens are 40x40x160mm3. There are totally 60 specimens according to mathematical model, 9 with hybrid fibered and 3 with surface treated fibered mortar specimens produced. Extensive results of mechanical, weight-loss and viscosity of mortars is discussed in result and discussion part.