عنوان مقاله [English]
Foam concrete is new cover for several usages in building industry that is very useful because of its unique specification. The high value of strength to weight ratio, low Thermal conductivity Coefficient and the high Heat insulation and soundproof ability is the most advantage of this type concrete. In this investigation we use Polypropylene fibers, Synthetic fibers, rice husk ash and nano silica to improve the foam concrete abilities. The fibers are used as additive and rice husk ash & nano silica are replaced as cement. The compressive strength test, tensile strength test and lentgh change test are performed on all foam concretes. Maximum compressive strength belongs to designs containing 1% synthetic fibers and 1% nano-silica. Finally, it was determined that rice paddy ash in 5% replacement has a 9% increase in compressive strength of 28 days and a 17% increase in tensile strength of 28 days. Compressive strength is not affected by Polypropylene fibers in 0.1% and 0.2%, and in 0.3%, compressive strength decreases. Adding 1% of synthetic fiber to concrete foam has 17% growth in compressive strength and 75% growth in tensile strength. Adding 1% nano-silica to foam concrete has a 20% growth in compressive strength and 38% growth in tensile strength. Nanosilica and rice husk ash decreased by 21% and 9% decrease in concrete shrinkage due to decreased absorption of foam concrete. Polypropylene and synthetic fibers cause 6 to 15% reduction in the contraction due to concrete drying.