Biomass Ash Cement Blends

The research was aimed at producing low cost durable cement extenders from ash residues of agricultural co-products to enhance sustainable utilization of natural resources. Agricultural residues such as rice husks, wheat straw, maize stalks and industrial wastes such as sawdust and ashes present disposal problems to authorities. Cement is the main constituent material in the construction industry. However, the production of cement contributes up to 10% of the global CO2 emissions. Furthermore it is an expensive commodity to a majority of low income earners in emerging economies.

Utilization of Biomass ash from Rice husks and Jatropha Husks as admixtures to cement improved its workability and increased or maintained compressive strength of control mortars respectively. The compressive strength gained using Rice Husk Ash (RHA) as cement replacement increased with an increase in proportion of cement replaced.

Compressive Strength Tests under this study has indicated that partial replacement of cement with biomass ash (Bioash Cement) is more superior to using ordinary composite cement (CEMIIA-L). The water to cement ratio required was lower, the cement products were lighter (lower density) and it was economic since Bioash was made from by products normally considered as waste in other processes.

The potential for the commercial production of Bioash for cement application has been explored and a 3 system design approaches discussed. It has been found that integration of Biomass types (at least 3) would provide sustainability of supply of raw materials. Ash obtained from a decentralized Biomass fed CHP systems was evaluated to be economically feasible.

The research demonstrated a strategy to attain the integration of waste management and carbon dioxide emission reduction to improve the quality of life of low income earners through access to affordable but durable construction material.

Keywords
Bioash Cement, Biomass, Biocrete, Concrete Strength Modelling, RHA, SSA, JHA, PFA, RMA, BCA