Influence of Barley Husk Ash with Nano- Silica on the Concrete Behavior

World-wide agricultural footprint is fast growing, with vast agricultural land cultivation and active expansion of the agro based industries. Agriculture is the most economic activity of Iran and other developing nations. In other hand, with the emergence of nanotechnology, inclusion of nano-materials in cementitous composites was a subject of many studies. Reportedly, nano materials enhance properties of cement matrix through several mechanisms. For example, nano- silica with high amount of SiO2 increases the pozzolanic reaction rate and leads to a stronger interfacial transition zone and denser microstructure of the cement matrix.
In this study, effects of barley husk ash with nano-silica on the concrete were investigated. Nine design mixes of barley husk ash separately or with six percent of nano- silica were casted for compression tests, tensile strength, and water absorption ratio. One of the major findings is that concrete that incorporates fifteen percent of barley husk ash weight of cement showed better mechanical properties than twenty percent. Also, it was found that with the addition of six percent of nano-silica with ten percent of barley husk ash, both compression tests and tensile strength increased. The results show that nano- silica decreases ultrasonic pulse velocity.