Impact Strength of Concrete with Nano Materials at Elevated Temperatures

Nanocomposite is a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometers (nm), or structures having nano-scale repeat distances between the different phases that make up the material. Nano composites are produced by adding nano-particles to a material in order to improve the properties of material. . The materials such as nano cement, nano-silica, nano flyash, nano metakaolin are being combined with cement. The use of finer particles (higher surface area) has advantages in terms of filling the cement matrix, densifying the structure, resulting in higher strength and faster chemical reactions i. e. hydration reactions. Nano-cement particles can accelerate cement hydration due to their high activity. Similarly, the incorporation of nano-particles can fill pores more effectively to enhance the overall strength and durability. Normally, the particle size ranges between 1nm to 100nm, they are generally called as nano materials. The fineness can reach up to molecular level by special processing techniques. An experimental investigation has been carried out to determine the influence of concrete with nano-particles such as (nano-cement, nano-fly ash, nano-metakaolin,& nano-silica fumes) under elevated temperature. M30, M40 and M50 grades of concrete were cast. For each of grades of concrete, 10 %, 20 % and 30 % of cement was replaced with nano-materials. The particle size of the nano-materials was determined using a Scanning Electron Microscope (SEM). Impact strength of concrete with nano materials under various elevated temperature (250C, 500C, 750C and 1000C) were found by using Impact Testing Apparatus. Impact strength is found to be least for the concrete specimens with replacement of nano-metakaolin. It was also found that impact strength of M30 grade concrete specimens was low as compared to other grades of concrete ( M40& M50).