Statistical Analysis on the Influence of Recycled Concrete Aggregate on the Concrete Properties

The construction industry alone in India produces 10–15 million tonnes of waste annually. In new construction, usage of recycled concrete aggregate provides major benefits like reduction in environmental pollution and conservation of nature. In the present study, the different percentages of recycled concrete aggregate (0, 50, and 100%) are used as a replacement to natural coarse aggregate in concrete. The concretes are tested for workability and strength properties for the water to cement ratios: 0.40, 0.45, and 0.50. The experiment was designed using Minitab software. Taguchi method with L9 orthogonal array was selected for the variables: w/c, RCA content, mixing time, and curing period. The strengths were measured at 7, 28, and 56 days. F-value and P-value of ANOVA test were analyzed to understand the influence of variables on the concrete. Statistical analysis proved the negative impact of recycled concrete aggregate on workability. The strength test results indicated reduced strength for more than 50% replacement of recycled concrete aggregate.