CEE April-June 2012

SQI•r P•n•l Brldq•D~k t\opru Luv..n"'"' Wlr•l•sa T•l•m•try ""-• P.....,lt fUbf'>SUJ llrtlfltn I a.l,..nuf 'Yb>l S,.a\oel,., ........... 8.o~an & l \01 L-.1 Cont,.,l Unit AkJih KOprOnun :>•m•Uk tUr (,()llrt 1011 Figure 4b. Smart concrete structures (A bridge embedded nano sensors placed in the critical parts and thus planned as damage can be controlled by remote monitors)[30]. cables are located in concrete, in the case of load applied on the concrete, there appear some stretch, cracking and fracturing due to this loading and there occurs a resistance difference and this effect causes appearing an electrical current change in the fibre cable so this change is also monitored remotely.)[30] Nano-AI 2 0 3 has been shown to significantly increase the modulus of elasticity up to 143 per cent at a dosage of 5 per cent, but to have a limited effect on the compressive strength, and no novel properties have been reported [3]. Nanoclay particles have shown promise in enhancing the mechanical performance, the resistance to chloride penetration , and the self– compacting properties of concrete and in reducing permeability and shrinkage. Additionally, non– modified, nano-sized clays were observed to act as nucleation agents for C-S-H [3] . Natural pozzolan being low cost and has low pollutant emissions, since increase the life of concrete together with existence in large amounts in nature, is used widely in the production of cement and concrete. Nano natural pozzolan produced by sonochemical methods, decreasing the amount of free calcium hydroxide (Ca(OH )2) during pozzolanic reactions, removes negative effects that influences on mechanical properties and long term duration of concrete. Moreover it increases the formation of calci um silicate hydrate (CSH) and calcium al uminate hydrate (CAH) which are so effective crystals on the strength of concrete. To increase the pozzolanic activity of natural pozzolans 2G-50 nm in size nanpozzolans prepared. By sonochemical process mentioned above reaction is performed at 5000°C temperature and 500 atm. , pressure. Sonic sound waves and microjets are used in this process. The main working principle is based on sending sound waves into liquid. Pozzolanic reactivity is measured by thermal gravimetric method. This process occurs with decomposing the calcium hydroxide which has crystal structure to CaO and water as thermal at the temperature between 400 - 500 °C. Ca(OHh consumption versus time is calculated. In performing experiments reactivity of nanopozzolan increased two times with respect to normal pozzolan. As the compressive strength of mortar with natural pozzolan is 83 MPa and 104 MPa after 7 and 28 days, respectively, using nano natural pozzolan which yielded compressive strengths of 112 MPa at 7 days and 129 MPa at 28 days were obtained for the cement specimens [34]. Polymer reinforcement methods is try to start in concrete production in recent times. To support CSH crystals chains and intending to repair damaged parts of which, polymer reinforcements being functional in nano conditions are made. To recent research, CSH elastic modules provide an increase as parallel to the increase in average 16