Since concrete is the most important building material used in construction industry globally, its production has become expensive over the years due to an increase in demand for housing. This has led to an increase in prices of both aggregates and cement. One of the development goals of Kenya’s big four agenda is to provide affordable housing to all people especially in slums and shanties, this may be seamlessly achieved by provision of quality and affordable building materials such as aggregates.

When the rainy season starts in earnest, the residents of Nairobi have several problems. The life of an average person living and/or working in the city often suffers economic, employment, health, and security challenges. First, most of the major roads within the city (already dilapidated and sporting gaping potholes) become inaccessible to pedestrians. During ‘average’ instances, the waters across roads are knee-length and it becomes practically impossible for office workers to retain the right outlook for their jobs.

There are various problems facing the construction industry. These problems include high cost of cement, resource depletion and global pollution. The cost of cement is on the rise due to increase in demand and rising mining levies. In addition the source of cement which is majorly limestone will deplete over time due to over mining. Furthermore limestone is the main reason for the emission of CO2 to the environment since it contains the vital compound needed, which is calcium carbonate.