بررسي خواص فيزيكي و مكانيكي آجرهاي حاوي ضايعات سنگبري تقويت شده با الياف پلي پروپيلن و الياف ضايعاتي سلولزي

Polymer bricks are a category of materials that, through the targeted combination of reinforcements, construction materials, an‎d the design of simple components, primarily exhibit superior properties compared to raw materials. In the present study, aiming to improve the physical an‎d mechanical properties of bricks an‎d reduce energy consumption, waste rock powder, polypropylene fibers, an‎d waste cellulosic fibers were substituted alongside a cold curing process using melamine formaldehyde resin. Considering the goal of producing lighter samples an‎d the reaction between citric acid an‎d lime in various treatments, a relatively high porosity (ranging from 38% to 51%) was achieved. The independent variables examined in this research included fiber percentage, length, an‎d type. The dependent variables studied were density, porosity percentage, water absorption percentage, flexural strength, compressive strength, volume fraction, an‎d fracture toughness. Mechanical analyses demonstrated that the flexural strength of samples increased from 0.75 MPa in the control sample to 1.98 MPa in the sample containing 0.2% polypropylene fibers. Additionally, the compressive strength of samples reinforced with waste cotton fibers improved up to four times compared to those containing polypropylene fibers due to higher adhesion arising from the common hydro‎philicity of the fibers an‎d matrix. Fracture toughness eva‎luation also indicated a 4.6-fold increase due to the fibers’ presence. Besides mechanical tests, microstructural examination by scanning electron microscopy an‎d fracture toughness testing were performed. The fracture toughness increased by 1.68% in the optimal condition compared to the control sample. The results showed that using recycled cellulosic fibers along with rock powder as an environmental challenge an‎d the cold curing method can lead to the production of lighter materials with acceptable mechanical performance, lower production costs, reduced labor requirements, an‎d ultimately decreased energy consumption an‎d environmental protection.

مهدي حجازي

كياچهر بهفرنيا

محمد شيخ زاده , حسين حسني