American J. of Engineering and Applied Sciences 3 (2): 277-285, 2010 ISSN 1941-7020 © 2010 Science Publications Corresponding Author: D. Raj Kumar, Department of Civil and Structural Engineering, Annamalai University, Annamalainagar-608 002, Tamilnadu, India Tel: +91 4144 239732/+91 9944077243/+91 9443488394 Fax: +91 4144 239732 277 Acrylic Rubber Latex in Ferrocement for Strengthening Reinforced Concrete Beams D. Raj Kumar and B. Vidivelli Department of Civil and Structural Engineering, Annamalai University, Annamalainagar-608 002, Tamilnadu, India Abstract: Problem statement: In India, the early deterioration of reinforced concrete structures has become a big social problem in recent years. An essential research is needed for the development of effective repair materials and their execution systems comes to an important issue from the viewpoint of the longevity of infrastructures at present. Ferrocement laminates are introduced to enhance the overall performance of Reinforced Concrete (RC) structures and these days the use of it is a promising technology for increasing the flexural strength of deficient reinforced concrete members. Approach: The repair system aims to provide quantitative repair enhancement as well as extending the life of deteriorated concrete members. This research in particular inspired the initiation of the present work which aimed to develop a material with unique properties and a very wide range of practical applications. The mechanical properties of mortar through difference in polymer content with Acrilic Latex by ferrocement among three different volume fractions of mesh reinforcement were studied. Following the encouraging progress made in the formulation and evaluation of the polymer modified repair mortar, tests were carried out involving the application of the reinforced repair material to the soffit of the reinforced concrete beams of 3 m length. Results: The levels of damage of the original beams prior to repair did not affect the ultimate load of the strengthened beams tested. The performance of the strengthened beams was compared to the control beams with respect to cracking, deflection and ultimate strength which confirm preeminent results. Conclusion: This accomplished the fact that acrylic rubber latex modified ferrocement is a doable alternative strengthening component for the rehabilitation of reinforced concrete structures. Further developments in these systems will create dramatic improvement into the field of rehabilitation of old privileged structures. Key words: Ferrocement, polymer, mortar, volume fraction, beams, laminates, mechanical properties INTRODUCTION A large number of civil infrastructures around the world are in a state of serious deterioration today. Moreover many civil structures are no longer considered safe due to increase load specifications in the design codes or due to overloading or due to under design of existing structures or due to lack of quality control. In order to maintain efficient serviceability, older structures must be repaired or strengthened so that they meet the same requirements demanded of the structures built today and in future. Ferrocement over the years have gained respect in terms of its superior performance and versatility and now is being used not only in housing industry but its potentials are being continuously explored for its use in retro-fitting and strengthening of damaged structural members. Ferrocement is a type of reinforced concrete commonly constructed of hydraulic cement mortar reinforced with closely spaced layers of relatively small wire diameter mesh. The mesh may be made of metallic or other suitable materials. Thinking ferrocement as a material to be applied to thin walled it is necessary to adjust the material properties to the construction type and acting forces in the structures, to obtain the proper strength, stiffness, cracking control, ductility and impact resistance. Water soluble polymers and aqueous polymer dispersions are often used to improve the properties of mortar. Polymer modified mortars are being used as a popular construction material because of their excellent performance. Polymer-modified mortars are generally superior in the resistance to oxygen diffusion to unmodified mortar. Consequently the use of polymer-modified mortars as repairing and finishing materials can be recommended in order to inhibit the wet corrosion of reinforcing bars in concrete