Abstract:
This research is focused on recycling of aggregate obtained from demolition and waste produced in the construction industry. With the advent of industrial revolution, construction industry witnessed an exponential growth especially in the 20th century after the cursed events of world wars. The demand for the materials used in production of concrete endorsed an unprecedented demand which are all non-renewable resources and all play a vital role in sustaining all forms of life on earth. The use of recycled concrete aggregate in our regular construction projects will not only reduce the strain on the production plants but also promise a brighter future for the human race. The myths of lower quality and strength of recycled concrete aggregate are discussed in this thesis with comprehensive testing conducted on cylinders casted with different ratios of recycled concrete aggregate (RCA) on different days. The trends obtained are then discussed with different approaches and conclusions are made at the results obtained. Cylinders of 4” diameter were used with 0, 10, 20, 30 and 40 percent replacement of RCA with virgin coarse aggregate and tests were conducted on 3, 7, 14 and 28 day after casting the cylinders. Afterwards the behavior of concrete with different ratios of RCA was analyzed thoroughly to make conclusions and recommendations for future based on the results. It was observed that the strength of concrete decreases proportionally with increase in percentage of RCA whereas the increase after 30% doesn’t follow the trend. We saw an abrupt change in behavior after crossing the value of 30% replacement by the recycled concrete aggregate. Hence the use of recycled concrete aggregate (RCA) in the routine construction works will not only assure economic footprint but also boost sustainability and recycling in our industry. Still there is a lot of potential research to be conducted in this field especially in Pakistan where construction industry is still in its infancy and a lot of work is to be done in this topic.
