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
means the supply of husks is greater than the demand thus they cause environmental
After animals are slaughtered, some of their bones are used in production of bone pastes, animal
feeds and glues (Meat Machinery, 2021). However, in most urban areas most of these bones
are disposed of thus posing inherent danger of environmental pollution and nuisance.
The government of Kenya has tried to put up mechanisms to supply over 500,000 units of
affordable housing as part of its Big 4 Agenda (Graham Kajilwa, Jan 2022). However, due to
the high cost of cement, the target may not be attainable in the next few years as planned.

Degree Program
Project Supervisor
Eng. Wokabi
Student Name
JESSE HERBERT JUMA F16/127706/2018