Influence of PVC waste powder and silica fume on strength and microstructure properties of concrete: An experimental study

The purpose of this study is to report the findings on fresh, mechanical & microstructural properties of an experimental investigation, which is performed by varying percentages of polyvinyl chloride (PVC) waste powder in an attempt to replace cement in M40 grade concrete partially. While, preparing test specimens of concrete, 8 % silica fume is kept constant and PVC waste powder (PWP) was varied in 0 % (treated as control specimen), 5 %, 10 %, 15 %, 20 %, 25 % & 30 % by weight of cement. A slump test is conducted to investigate fresh properties of concrete. At the same time, mechanical properties of concrete like compression, split-tensile & flexural strength were investigated at 7,14,28 & 90 days of curing period. The findings of this investigation indicate that up to 15 % PWP can be used along with 8 % silica fume in M40 grade concrete, without compromising on fresh and mechanical properties of concrete. Similarly, the microstructure of concrete prepared with 15 % PWP indicates the improved calcium-silicate-hydrate gel compared to mix prepared with 20 % PWP. Thus, the use of PWP up to 15 % dosage is more beneficial while using it as a partial replacement of cement along with fixed contents of silica fume (8 %). Authors believe that their investigation will help researchers and practitioners active in the building materials in addressing the challenges of increasing demand for cement and will also be useful in dealing with plastic waste-related difficulties in a meaningful manner.