Production of high performance nano concrete using mixed puzzolans

PRODUCTION OF HIGH PERFORMANCE NANO CONCRETE USING MIXED PUZZOLANS Volkan ÖZDAL Düzce University Graduate School of Natural and Applied Sciences, Department of Civil Engineering Master's Thesis Assist: Prof. Dr. Serkan SUBAŞI July 2019, 93 pages Structures are required to be durable against external influences and have longer service life. Therefore, the importance of high performance concretes has increased with the recent improvements in concrete technology. High performance concrete refers to an improved concrete in terms of mechanical properties and as well as durability properties. The use of puzzolans has become widespread to improve the durability properties of concrete. In addition, puzzolanic materials as fly ash, silica fume, metakaolin and blast furnace slag are used for more economical concrete production. The use of pozzolans by replacing them with a certain rate of cement is becoming an increasingly researched topic. The usage of this kind of mineral admixtures is a big step to obtain more green and clean nature. Moreover, they improve the mechanical properties of concrete with their fine graded forms and puzzolanic reactions. At the same time, the use of nano materials to improve concrete properties is also increasing. The aim of this study is to produce a high performance nano concrete using mixed puzzolans. For this purpose, basalt aggregate and TiO2 nano filler materials were used and metakaolin and blast furnace slag were added as single or mixed compositions. Firstly, concrete mixtures having 3 different grain distributions were prepared with basalt aggregate. 5%, 10% and 20% metakaolin and blast furnace slag were added to the concretes having the highest concrete compressive strength among prepared concretes with different grain distributions. In addition, puzzolans were added to concrete mixtures with different mix ratios. Compressive strength, water absorption and flexural tests were performed on the concrete samples. In this study, mixed usability of pozzolans has been investigated. As a result, it has been found that the single use of pozzolans yields better results in terms of compressive strength. Moreover compressive strength of concrete increases with the use of nano materials. Keywords: Pozzolan, Nano material, Concrete, Strength.