EVALUATION OF FRESH-STATE BEHAVIOR OF RECYCLED AGGREGATE CONCRETE (RAC)

Abstract

As we all know that worldwide demand for virgin or natural aggregates has put strain on existing natural resources and led to several environmental problems. On the other hand Construction & Demolition waste has turned out to be a major issue in the recent years. In such an alarming situation tons of research work is being done to find a solution to this dilemma. Recycled Aggregates have turned out to be the most viable and feasible alternative to natural aggregates which would not only help in promoting sustainable development but environmental preservation as well. Recycled aggregates (RCA) are obtained by crushing of construction demolition debris and are surely the materials for the future. Many countries have now made guidelines to incorporate the use of recycled aggregate and have started wide-scale use of recycled aggregates in construction projects. Based on the extensive research in recent years it has been shown that recycled aggregates can be well used to manufacture concrete with characteristics similar to that of concrete produced using natural aggregate. Nevertheless, it is still unclear to what extent recycled aggregates can replace natural aggregates in concrete without materially altering the concrete's short- v term or fresh-state qualities. This research aims to investigate the Fresh-State properties of RAC and determine the percentage of recycled aggregate that can be substituted for natural aggregate in M30 grade concrete to achieve the required workability and strength while utilizing Portland Pozzolana Cement based on Fly Ash. In this experimental investigation trial mixes were prepared with varying proportions of recycled aggregate and after concrete was produced it was tested for its fresh-state behavior. The research methodology involves preparing concrete mixtures or trial mixes with varying proportions of recycled aggregates and conducting comprehensive testing to assess their mechanical performance. Laboratory tests, including compressive strength and durability assessments are carried out to evaluate the behaviour of fresh-state behaviour of RAC Generally, workability and strength are the two main properties that consumers demand for construction activities. This investigation clearly demonstrates that RA can be fully used to replace NA in concrete in terms of workability and strength for small scale constructions.