COMPUTATIONAL RESEARCH PROGRESS IN APPLIED SCIENCE &ENGINEERING (CRPASE) CRPASE: TRANSACTIONS OF CIVIL AND ENVIRONMENTAL ENGINEERING Journal homepage:http://www.crpase.com CRPASE: Transactions of Civil and Environmental Engineering, Vol. 06(04), 276-280, December 2020 ISSN 2423-4591 Research Article Application of Nano Silica to Improve Self-Healing of Bitumen Mixtures Pala Gireesh Kumar  Department of Civil Engineering, Shri Vishnu Engineering College for Women (Autonomous), Bhimavaram, India Keywords Abstract Bituminous Mix, Healing Index, Marshal Test, Nano Silica, NSMB. Rutting and cracking are two common modes of failures in asphalt pavements. Due to increase in traffic volume and traffic loads, asphalt pavements get deteriorated gradually during their service life. Deterioration of asphalt pavements can be eliminated/minimized by enhancing the quality of bitumen and with modified bitumen. The use of nano materials as an additive because of its special characteristics is one of the self healing technique which have the potential to improve the pavement performance, extending its life span and also eliminating the need for pavement maintenance. This research work investigates the performance of nano silica in asphalt pavement. Experiments were conducted on bitumen and modified bitumen (addition of nano silica of different percentages, 2%, 4%, 6%, 8% and 10% with bitumen) in order to find the optimum nano silica content for preparing Marshal Mix. It was found that, for 6% of nano silica in modified bitumen, gave improved properties among other percentages of nano silica contents that are examined. Nano silica modified bituminous mix (NSMBM) samples were prepared for various bitumen contents, i.e., 4.5%, 5% and 5.5% and conducted marshal stability test. This study concludes that, the results obtained from marshal test gives higher stability value (10. 32 kN to 20.18 kN) and lesser flow value (4.48 mm to 2.60 mm) for Modified bituminous mixes over unmodified bituminous mix samples. Finally, the healing index was also determined based on theoretical approach and obtained 80 % healing rate for modified bituminous mix. Further investigations can be carried out on long term effects of NS in asphalt pavements as well as test rest periods for different temperatures and different loads. 1. Introduction With increase in countries population and increase in traffic volume causes pavements to experience the continuous loading which leads to pavement distress problems. The challenge for road engineers is to develop a sustainable asphalt mixture that reduces the likelihood of the pavement system failure by developing new road materials and new methods in road construction and maintenance [2, 3, 19, 20]. Since 2008, the incorporation of self-healing technology into asphalt pavements has been advancing and gaining importance in recent times [4, 5]. Self-healing technology had become an alternative solution for road maintenance, where the damage is repaired by an internal healing system [14, 1]. Rise in temperature will increase the healing effect of asphalt concrete; as a result of healing, the service life time  Corresponding Author:Pala Gireesh Kumar E-mail address:palagireeshk@gmail.com Received: 1 November 2020; Revised: 12 November 2020; Accepted: 15 November 2020 Please cite this article as: P. G.Kumar, Application of Nano Silica to Improve Self-Healing of Bitumen Mixtures, Computational Research Progress in Applied Science & Engineering, CRPASE: Transactions of Civil and Environmental Engineering 6 (2020) 276–280. of asphalt concrete will increase [13]. However, it is well known that, the healing of asphalt concrete is a temperature dependent phenomenon, and the healing mechanism has been reported by many researchers as increase in the test temperature results in increasing the healing rate and shifts the recovery response to a shorter time [11]. A trial section was constructed on Dutch motorway A58, in December 2010, and applied induction healing technique in real porous asphalt road which results in survival of train section for the three winters perfectly [12]. Cracks can be healed internally with the application of self healing material in asphalt concrete when subjected to rest periods with its mechanical properties [12]. Since 1960s, numerous studies were conducted on self healing asphalt concrete [11] and found cracking as one of the major failure modes of it [16].