The construction industry is a major part of Kenya’s economy. Nairobi, being the capital city, is experiencing rapid growth and development, leading to an increase in construction projects. However, ensuring effective construction management and safety practices remains a significant challenge.

Recent studies have shown that the rise in population and industrialization of urban centres leads
to an increase in sewage disposal. Lack of proper waste management presents the likelihood of
environmental and health hazards such as open sewer lines, especially in low-income areas.
Therefore, there is a need to provide methods of wastewater treatment whether on-site or by
conveyance to treatment sites. Due to the likelihood of overloading wastewater treatment plants, it

Due to the high cost of construction, there has risen need to find cheaper alternatives to partially
replace cement. Studies have been carried out on different materials such as wood ash and fly
ash in partial cement replacement. This research is however based on partial replacement of
cement using bone and coffee husks ashes.
Coffee is one of the crops majorly grown in Kenya for export. After processing, the husks are
normally disposed of and only a little amount is used as manure and as fuel when dried. This