# Cow Dung Ash in Mortar: An Experimental Study  
[PERSON]  
1 Department of Construction Technology and Management, Woldia Institute of Technology, Woldia University, Woldia 7220, Ethiopia 1  
[PERSON]  
2 School of Research and Graduate Studies, Arcada University of Applied Sciences, Jan-Magnus Jansson Aukio 1, 00560 Helsinki, Finland 23 Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, 3  
Bahir Dar 6000, Ethiopia 3  
[PERSON]  
4 University of Applied Sciences, Woldia University, W  
Reducing carbon emissions from the cement industry is a significant challenge, but there are several approaches that can be taken. One of the most practical, economical, and sustainable approaches to reducing the CO2 emissions caused by the concrete industry is the use of a sustainable system loop that can transform waste resources into valuable products. This approach provides a range of advantages that go beyond reducing clinker content and associated carbon emissions. It enables a reduction in the use of conventional cement ingredients such as limestone, thereby conserving valuable natural resources. Moreover, repurposing waste materials that would otherwise end up in landfills promotes waste reduction and diversion, thereby fostering more sustainable waste management practices. In the past two decades, several studies have already explored supplementary cementitious materials (SCMs) derived from industrial and agricultural byproducts [4; 5; 6; 7; 8; 9; 10; 11]. These include silica fume, fly ash, blast furnace slag, rice husk ash, coffee husk ash, ground nut ash, bamboo leaves ash, banana leaves ash, sugarcane bagasse ash, corncob ash, animal bone ash, tobacco waste ash, glass powders, coal bottom ash, and eggshell ash. Several studies have also investigated the potential of waste materials to replace various ingredients used in concrete production, including the use of recycled aggregates, coconut fibers, glass, marble, and rubber tree seeds [12; 13; 14; 15; 16; 17; 18]. The objective is to conserve natural resources and address the environmental impact caused by these waste materials. By substituting conventional ingredients for waste materials, the concrete industry can contribute to resource conservation and mitigate the burden on the environment. In recent years, researchers have studied the potential of cow dung ash (CDA) as a supplementary cementitious material. Cow dung, a byproduct of cattle farming, is known for being a rich source of silicon dioxide, and thus has pozzolanic properties [19]. It also contains organic matter, including fibrous materials that have passed through the cow's digestive system. The chemical composition of cow dung typically consists of carbon, nitrogen, hydrogen, oxygen, and phosphorus, as well as potassium and calcium [20]. [PERSON] et al. [21] investigated the effectiveness of using 10% CDA and 20% rice husk ash (RHA) in concrete under varying curing conditions. The researchers concluded that incorporating both SCMs in the concrete resulted in greater strength. Another study was conducted to evaluate the performance of concrete with 15% CDA that was exposed to water [22]. The specimens were cured for 28 days and then exposed to fresh water for different durations of time: 56, 90, 180, and 365 days. The results showed that the concrete with CDA had superior pH, compressive and split tensile strength, and durability compared to normal concrete. The researchers also observed a lower bacterial density in the CDA-containing concrete. According to Statista, Ethiopia has a significant population of cattle, ranking fifth in the world and holding the top spot in Africa for total count. The primary use of cow dung in Ethiopia is as a source of fertilizer, and it is also dried to serve as fuel for cooking purposes. With the Ethiopian government's ambitious plan to provide electricity to all citizens by 2025 [23], the rural population of the country will eventually shift towards using electricity for energy, potentially resulting in wasted cow dung.