Feasibility of using egg shell powder as a partial replacement of Lime in stabilizing Gravel Material on construction of rural roads; case study of Mbarara.

Abstract

According to (UBOS, 2016), The Uganda national roads network totals to 20,544km comprising paved and unpaved roads. As of June 2016, the paved was 4,157kms (20 %) and the unpaved 16,388km (80 %). The unpaved are sometimes also referred to as low volume roads or gravel roads and their construction is more often than not found to be challenging; the volume of earthwork to be quarried and hauled is mind boggling. Road engineers strive to conserve natural resources for future generations while providing aid to the rural community with the rural connectivity to facilitate a positive impact on social services, agricultural, employment and economic opportunities to rural masses. In the case of rural community roads, which amount to over 30,000 km in total, the cost of sealing is rarely justified and the norm is to use laterite, which can be distant and expensive, and always requires intensive maintenance and re-grading after each rainy season. The laterite soil is subject to wind erosion and the extra dust caused from this material is causing a major health problem (BASIIME, 2016). Lime and waste egg shells are available in Uganda and stabilization has potential benefits that include greatly reduced road life cycle costs, ability to use more locally available materials, and reductions in dust emissions. As of 2016, around 80 million metric tons of eggs were produced annually worldwide (statista, 2016), 883 million eggs were produced annually in Uganda according to UBOS statistical data 2017.