Studies on Impact Strength of Concrete with Nano-Materials at Elevated Temperatures

Nano composites are produced by adding nano-particles to a material in order to improve the properties of material. Concrete is a material most widely used in construction industry. Concrete is a composite material made up of cement, sand, aggregate, water and mineral or chemical admixtures. The materials such as nano-silica, nano flyash, nano metakaolin are being combined with cement. There are also a limited number of investigations dealing with the manufacture of nano-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 to100nm, 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-cement particles under elevated temperature. M20, M30 and M40 grades of concrete were cast. For each of grades of concrete, 10%, 20% and 30% of cement was replaced with nano-cement. The particle size of nano-cement was determined using a Scanning Electron Microscope (SEM). Impact strength of concrete with nano materials under various elevated temperature (250°C, 500°C, 750°C and 1000°C) were found by using Impact Testing Apparatus. Impact strength is found to be least for the concrete specimens with 30% replacement of nano-cement. It was also found that impact strength of M40 grade concrete specimens was low as compared to other grades of concrete (M20 & M30).