Evaluation of the effectiveness of straw fibers on the mechanical properties of concrete containing zeolite and bentonite

Cement is one of the most widely used materials in the construction industry, which emits large amounts of carbon dioxide into the environment during production. Environmental challenges and the reduction of energy consumption and the use of natural raw materials have led to increased study and research to find a suitable alternative to cement. Zeolite and bentonite have cement properties. These materials are environmentally friendly and can be easily extracted and also have lower production costs than cement. Since concrete has a low tensile strength, straw fibers, which are natural fibers, have also been used. In this research, 9 different mixing ratios with the amount of 250 kg / m3 cement were made in which different percentages of bentonite and zeolite replaced part of the original cement and the percentage of fibers varied by 1% and 3%. After fabrication, the compressive strength and tensile strength of the samples compared to the reference sample at 7 and 28 days have been compared. Then, two concrete mixtures with 6% zeolite, 1% straw fiber and 6% and 16% bentonites were selected and three-point bending strength test was performed on beams with dimensions of 10 * 10 * 50 cm. The flexural strength of the reference sample in this section, which contains 350 kg / m3 of cement, is 5.37 MPa. The best composition contains 6% zeolite, 6% bentonite and 1% straw fiber, which was able to achieve 98% flexural strength compared to the reference sample.