تقييم استخدام غبار المحاجر كبديل للرمل الطبيعي في الخلطات الخرسانية: مراجعة علمية

The increasing reliance on natural sand in concrete production has led to the depletion of natural resources, prompting researchers to investigate more sustainable alternative materials. One such alternative is quarry dust, a by-product generated during the crushing of rocks for the production of coarse aggregates. This study reviews twelve experimental research papers published between 2007 and 2019 that investigated concrete mixtures within structural strength classes ranging from C20 to C45. Most of the reviewed studies focused on quarry dust derived from granite rocks due to their favorable mechanical and mineralogical properties for concrete applications. Based on the findings of these studies, the optimal replacement ratio of natural sand with quarry dust was identified as 60%. At this replacement level, an improvement in the mechanical properties of concrete was observed compared to the control mixtures. The 28-day compressive strength increased from 37.47 MPa for the reference mix to 47.24 MPa for the quarry dust-containing mix. Similarly, the splitting tensile strength improved from 4.46 MPa to 5.78 MPa for the reference and quarry dust mixes, respectively. In addition, the flexural strength increased from 9.93 MPa for the control specimen to 10.81 MPa for the specimen incorporating quarry dust. Despite the significant enhancement in compressive, tensile, and flexural strengths, the use of quarry dust was found to adversely affect the workability of concrete. However, this drawback can be mitigated through proper mix design optimization and the use of superplasticizers. Overall, the results of most studies indicate that quarry dust—particularly that obtained from granite rocks—represents a viable, low-cost, and sustainable alternative to natural sand, capable of achieving satisfactory mechanical performance when used under appropriate design conditions. Keywords: Quarry dust, natural sand, concrete mixtures, replacement ratios.