Performance of sustainable sand concrete at ambient and elevated temperature

摘要

Environmental issues resulting from the sand over dredging have contributed to worldwide restrictions on its production, with a significant economic impact on concrete construction. The demolished building waste is not widely recycled globally. A suitable, environmentally friendly approach with an adequate alternative to sand is introduced in the present study. Four types of concrete, natural dune sand concrete (NDSC), recycled crushed sand concrete (RCSC), recycled crushed sand stone dust concrete (RCSSDC), and recycled crushed sand crumb rubber concrete (RCSCRC), have been introduced in the present study. In-situ compressive strength of demolished building concrete has been measured by the Non-destructive test (NDT) core testing. In the present research work, recycled crushed sand (RCS) was substituted by natural dune sand (NDS) in the ratio of 40%, 100%, and 80% in mixes 40NDSC, 100RCSC, 80RCSSDC, and 80RCSCRC, respectively. A detailed physical analysis was conducted to evaluate material properties such as specific gravity, water absorption, particle grading, and sand equivalent value. The chemical analysis pH, FTIR, and SEM-EDX have also been carried out on stone dust (SD) and crumb rubber (CR). The concrete specimens were tested at ambient and elevated temperatures 100, 200, 300, and 400 degrees C for four hours in an electric oven. Experimental studies show a slight increase in the compressive strength of 10ORCSC (up to 300 degrees C) compared to 40NDSC. A sudden fall in the strength was observed at 400 degrees C for all concrete types 40NDSC, 100RCSC, 80RCSSDC, and 8ORCSCRC. Replacement of RCS at 20% by SD and CR indicated a decreasing pattern in compressive strength. The compressive strength reduction rate was more in crumb rubber, which indicates that crumb rubber should not be used in higher percentages in concrete. The concrete samples 40NDSC and 100RCSC performed significantly better than the other concrete types.