Utilization a Mixture of Eggshells and Husk Ash to Reduce Environmental Impact

Eggshell waste and husk ash are abundant in Indonesia, with a population of 263 million, which is estimated to reach 483,920 tons and 10 million tons, respectively. However, this waste has not been utilized optimally, so it has a negative impact on the environment. This study aims to analyze the quality (compressive strength and water absorption) of a mixture of eggshells and husk ash as paving blocks for buildings to reduce the environmental burden. The experiment was carried out using a 2 factor factorial design: eggshells (4 levels: 0%, 5%, 7% and 15%); and husk ash (4 levels:  0%, 5%, 8% and 10%). The data were analyzed using analysis of variance, followed by analysis of mean using the least significant difference (LSD). The results showed that the mixture of eggs and husk ash had good quality, so it could reduce the need for Portland cement, which has a negative impact on the environment during production process. The best quality of a paving block was a mixture of 10% of husk ash and 15% of eggshells (A4B4 treatment) with the compressive strength value of 39 Mpa and water absorption of 5.8% (good).