I hereby declare that the research entitled “Comparative study on natural sand from Dima and Worabe replaced by Crushed Sand for Concrete Works in Road projects around Jimma area”

Abstract

There is a global construction boom as nations urbanize and develop via the expansion of infrastructure. Ethiopia’s construction sector has also grown in an exemplary manner for the past few decades. In line with that, natural resources like river sand are depleted and become scarce in the market throughout Ethiopia.The construction sector has little understanding of this issue, as population growth drives rapid increases in construction and urbanization.This research was conducted to assess the use of crushed sand instead of natural sand for concrete works of road construction around Jimma area.The comparison focuses on quality and cost aspects. The impact of a different mix proportion of crushed sand on the workability, compressive strength, flexural strength, and splitting tensile strength qualities of concrete was examined using an experimental study methodology. The results of the test indicated that the natural Worabe sand and the Dima sand had fineness modulus of 3.00 and 3.02, respectively, which qualified them for use in concrete. However, the fineness modulus of the crushed sand was 3.30, which means that it cannot be used as a fine aggregate in concrete without blending. The test result from the experimental study indicated that using more natural sand in place of crushed sand aggregate somewhat boosts the workability of fresh concrete. The study found that using more crushed sand in place of natural sand aggregate somewhat boosts the compressive strength of concrete. A 50% mixture of manufactured and natural Dima sand produced concrete with a mean compressive strength of 34.84 MPa, above C-25. As crushed sand is substituted for natural sand in concrete, the splitting tensile strength increases until it reaches 100% replacement. An investigation into the impact of manufactured sand on the cost-benefit analysis of the concrete showed that mixes that substitute some or all of the natural sand with crushed sand saw a notable change in cost. The largest percentage cost reduction between 100% natural sand and 100% crushed sand is around 10.74%. In general, when crushed sand is substituted partially or completely, the concrete's compressive and split tensile strength is higher than that of river sand. Crushed sand should thus be used in the construction industry to optimize resource use and lower unnecessary material expenditures.