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The growing amount of waste materials and the shortage of landfill space highlights the urgency for alternative ways to recycle and reuse waste materials. Recycle and reuse waste materials would indirectly contribute to reducing the landfill space required for their disposal. This paper attempts to compare the physical and mechanical properties of byproduct material (steel slag) and waste material (Cathode Ray Tube (CRT) glass) that could potentially be used as substitutes for natural aggregates in the construction of road pavements. This paper discusses the feasibility of utilizing recycled steel slag and CRT glass which meet the test requirements for natural aggregates utilized for pavement construction. The study method for laboratory work was carried out following the American Society for Testing and Materials (ASTM) specifications. Physical and mechanical testing's, i.e. specific gravity, water absorption, soundness and Los Angeles abrasion tests, were carried out to determine the suitability of using steel slag and CRT glass in the construction of road pavements. Test results indicate that steel slag and CRT glass can be used as substitutes for natural aggregates due to their satisfactory physical and mechanical properties. It can be concluded that the use of steel slag and CRT glass as a replacement for natural aggregate resulted in the sustainable management of road base paving application. [ABSTRACT FROM AUTHOR]

Schmidt rebound hammer test was employed in this study as a nondestructive test. This test method has been universally utilized due to its non-destructiveness for quick and easy assessment of material strength properties and quality of concrete of an existing structure. Industrial waste materials (air-dried alum sludge, treated alum sludge, limestone dust and quarry dust) were employed as replacement material for fine aggregates in this study. A normal strength concrete was designed to achieve 35 MPa at 28 days, with industrial waste materials replacing fine aggregate at different percentages (0%, 5%, 10% and 15%), and then cured for 7, 28 and 180 days. The compressive strength values and rebound numbers for all the mixes obtained were correlated, and a regression equation was established between compressive strength and Schmidt rebound number. The correlation result showed an excellent relationship between rebound number and compressive strength of concrete produced in this study at all curing ages, with correlation coefficients of R2 = 0.98, R2 = 0.99 and R2 = 0.98. The predicted equation showed a strong relationship with the experimental compressive strength. Therefore, it can be used for the prediction of compressive strength of concrete with industrial waste as a replacement for fine aggregate. [ABSTRACT FROM AUTHOR]