DEVELOPMENT AND ANALYSIS OF RAPID RUNWAY REPAIR (RRR) TECHNIQUES

Abstract

An extensive literature review was done for the development of Rapid Runway Repair techniques. The fundamental theme of our research was to explore and develop the Rapid Runway Repair Methods (RRRM) for outright rehabilitation in an airfield having durable, long lasting and high early strength. We used three different types of cements i.e OPC, Kohat Green Bag cement and the High Alumina Cement. First, we optimized all these cements at the paste level by first finding the optimum water cement ratio and then reduced the initial and final setting times by conducting number of different trials. We used NaOH as an accelerator in High Alumina Cement and CaCl2 (Calcium Chloride) as an accelerator in OPC and Kohat Green Bag cements. First, we fixed the proportion of accelerator solutions and changed the molarity and found the optimum value of molarity and then we fixed that optimum molarity and changed the w/w proportion of the solution. After conducting many trials, we obtained the optimum results at 0.5 w/w of cement at Molarity of 4.5 for High Alumina and 1% w/w of cement with 2 Molar solution. The best setting time came to be of High Alumina cement which gave an initial setting time of 9 minutes and final setting time of 40 minutes. We also added 2% steel fibers which increased the flexural strength by 15%. After carrying out the testing in the lab, we did on-field non-destructive testing on the slabs of three different cements having the dimensions of 1.5 ft by 1.5 ft to study the various properties of concrete. The last phase of the project was to use finite element (FE) analysis technique in ABAQUS to explore the stress magnitude and distribution along the pavement and soil, under impact load of the air craft. This helped us simulate the real-world conditions and in turn the behavior of our concrete under the actual conditions. A total of three models were developed to compare the results of all three cements under investigations, to help us gauge which cement will give us the most beneficial results in the least amount of time