Evaluation of inorganic polymer as adhesive material for repair of reinforced concrete

Abstract

A new development in the repair and strengthening of reinforced concrete systems is the use of carbon fiber reinforced polymers (CFRP) strips bonded to concrete substrate with epoxy resins. It has been reported that epoxy adhesive used are extremely sensitive to high temperatures. Some authors conclude that the epoxy temperature should not exceed 70 º C in order to safeguard the adhesiveness of the epoxy and, thus, the integrity and adequate functioning of CFRP. It is noted that frequently exposure to direct sunlight causes temperatures higher than 70 ºC. Inorganic polymers are often referred to as geopolymers or alkali-activated cements and are known to possess high stability at high temperature. Tungsten mine waste inorganic polymer (TMWIP) is a new cementitious material, obtained from dehydroxylated mine waste powder mixed with minor quantities of calcium hydroxide and activated by NaOH and waterglass solutions. This paper reports some results on the bonding capacity of this inorganic polymer, i.e. TMWIP, and concrete. Results show that given the proper mix the new binder demonstrates high adhesion to concrete substrate.