Volume 39, Issue 5 (September 2011)
Effect of Initial Stress Levels on Strength Parameters of Reinforced Concrete Beams Retrofitted Using Ferrocement Jackets
Ferrocement jackets and sheets can be used for local rehabilitation and retrofitting of structures due to their high tensile strength, light weight, overall economy, water tightness, and ease of application. In the present paper the effects of number of layers of wire mesh in the ferrocement jackets, type of section (balanced or under reinforced) and initial stress level on the strength of retrofitted stressed reinforced cement concrete beams have been studied. The results show that there is higher increase in the maximum load, safe load carrying capacity, ductility and toughness for beams with three layers woven wire mesh ferrocement jackets as compared to beams reinforced with two layers of woven wire mesh. It is further seen that the percentage improvement in above properties decreases with increase in initial stress level and change in type of section from under reinforced to balanced. Subsequently an analytical model, based on principles of compatibility of strain and equilibrium of forces, has been presented to predict the safe and maximum load carrying capacity. It is found that predicted safe and maximum load carrying capacities are within 5 % of the experimental one.