The effect of using gypsum instead of aggregates on the physical and mechanical properties of cement mortars and the influence of polypropylene fibres

Cement is one of the common materials used in the construction industry. However, cement has many disadvantages such as low tensile strength, cracks over time, water absorption and chemical attacks. For this reason, composite materials have been produced for the needs by using different building materials together with cement. It is reinforced with different types of fibers to overcome the poor tensile strength, brittleness and cracking of cement-based mortars. Different types of fibers increase the tensile strength of cement mortars, prevent the onset and spread of cracks. Gypsum was used instead of aggregate in the cement mortar samples, which resulted in a decrease in the unit volume weight of the mortar samples. In addition, durable cement mortar samples were created by using the binding property of gypsum. In this study, 24 different polypropylene fiber reinforced and gypsum doped mixtures were produced by keeping the different types of polypropylene fiber content constant and using gypsum instead of aggregate. 4 More samples were produced by using a light aggregate instead of the existing aggregate with the best mixing ratios. A total of 28 samples were studied. 40×40×160 mm mortar samples were prepared for the studies. Physical and mechanical properties were evaluated by conducting water absorption, unit volume weight, ultrasound speed, three-point bending tensile strength and compressive strength experiments on the samples. It has been found that mortars using 10% gypsum by weight give better results than others, and Macroliferous OneShot Macro 48/45 polypropylene fiber provides the best contribution to mechanical properties. It has been found that the use of gypsum significantly reduces the unit volume weight of mortars. The use of polypropylene fiber has increased the mechanical properties of the samples.