A Review of Structures and Performance of Ternary Blends of Rice Husk Ash and Some Wastes in Concrete

The field of structural engineering has in recent times begun to widen its scope from the traditional analysis and design, into the development of new structural materials. This is because the use of non-renewable materials in forming and framing structural projects are raising serious environmental concerns bothering on sustainability of materials, especially cement, to produce structural concrete. Cement has been found to be a major contributor to greenhouse gases which affect the environment negatively. Waste from both the industrial and agricultural industries are gradually becoming sources of material to partly replace cement in concrete because of their pozzolanic properties. The agro-based pozzolanic materials include Rice husk Ash (RHA), Saw dust ash (SDA), Palm oil fuel ash (POFA) amongst others. To further widen the scope and resource base of pozzolanic materials for concreting, ternary blends consisting of agro-based pozzolans are being researched into. These research efforts however appear to be uncoordinated, and thus there is a need to juxtapose these efforts together to see the extent of work done on such ternary blends and present their relevant structural properties. This is with a view to helping identify gaps in such research as a means of preventing wastage of research energies. This paper presents a review of structural properties of some agro-based ternary blends used in structural concrete.  It is concluded that more research effort is needed, especially in the development of practical and acceptable guidelines that will aid their application in concrete, for sustainable production of structural concrete.