**6. Conclusion**

This study was conducted to alter cement in mud concrete technology. Mud concrete is a novel walling material discovered to alter compressed earth blocks. The concept of mud concrete block is to build concrete by soil. Sand and metal of concrete are replaced by a fraction of the soil. The precise gravel percentage governs the strength of mud concrete. The cement in this concrete is also used as a stabilizer. But the cement has this weakness of initial cost and the heavy carbon footprint. If cement in mud concrete can be replaced with a much greener stabilizer, mud concrete can be recommended as a greener walling material.

The study was conducted after a series of nature studies and literature studies. In addition, the folk knowledge also has been considered prior to the experimenting with stabilizers. Then, the study builds an inventory of possible stabilizer which may replace the cement and act as a stabilizer for soil. At the very beginning, the study was focused to develop natural polymer-based stabilizer because ancient Sri Lankan ancestors used natural polymers to stabilize the earth and build gigantic structures and plastered them with frescos. However, the utilization of natural polymers was an utter failure due to the availability of materials. The experiment with natural latex rubber and mud concrete achieved the required strength but there were many practical issues when it comes to the physical use of rubber-stabilized earth blocks. Then, a study was done with a series of natural polymers taken from other plants such as pines, chews, and so on. The results are good enough but practically cannot be applied in the real world where the mass production of earth blocks is required.

Then, the study was focused to utilize industrial waste into cementitious materials for mud concrete block. Fly ash, bottom ash and rice husk ash were subjected to this study and found astonishing results. The initial results with a raw form of waste were failure and they did not produce the required strength. And then, the developed mixture with alkaline solution creates much better strength with mud concrete block. After finalizing the mix and all, a sample wall area of 1 m × 1 m was built to check the practical application of this block to produce affordable walling. And it was noticed that highly alkaline solutions make the mixture somewhat difficult. The expanded study was conducted to rank the alternative stabilizers discovered in this study. The developed stabilizer was ranked according to their workability availability and the initial cost. And then, the extensive study was conducted with life cycle cost and carbon footprint analysis to understand the long-term use and the environmental impact of those stabilizers.
