The world of building materials is constantly and rapidly developing. New technologies are needed to reduce the cost of producing these materials and to ensure better efficiency when the materials are used in various engineering projects. One of these materials is high-strength concrete. This paper investigates the production of low-cost, high-strength concrete by partially replacing fine aggregates (FA) with waste glass sand (WGS). Four concrete mixes were considered in this study with varying percentages of WGS (0%, 25%, 50%, and 75%). For each mix, cubic, cylindrical, and beam specimens were cast to study the workability and different mechanical properties of concrete-like density, elasticity modulus, compressive strength, ultrasonic pulse velocity (UPV), split tensile strength, and flexural strength. In addition, the cost of each mix was calculated to evaluate the cost reduction efficiency of concrete with WGS compared to normal concrete. Results showed that the workability of concrete enhanced as the percentage of WGS increased. In terms of concrete mechanical properties, it was shown that the elasticity modulus, compressive strength, split tensile strength, and flexure strength for a concrete mix with 50% WGS as FA replacement was increased by 7%, 27%, 9%, and 50%, respectively. Also, it was concluded that the presence of WGS in concrete mixes reduced the production cost by up to 30% for a 75% replacement level. The authors recommended the usage of 50% WGS as the optimum replacement percentage for low-cost, high-strength concrete.

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Limitations to the sources of aggregates and the unavailability of sand is becoming a problematic issue for concrete production. A novel technology of manufactured aggregates can produce well graded round aggregates that can substitute natural aggregates while maintaining the same characteristics needed and preserving the resources. Self-Consolidating Concrete (SCC) using manufactured aggregates is assessed in this experimental work to understand the variability of workability properties and mechanical properties with the changes in w/c ratio and percentages of Coarse Aggregates and Manufactured Sand to Natural Sand in order to choose the best mixture that satisfies an adequate overall performance. Targeting compressive strength improvement, the SCC mixes included the use of Silica Fume (SF) and Polycarboxylate Superplasticizer which exhibited a strength improvement when compared to normal SCC. After performing 6 different trial mixtures, the use of manufactured rounded aggregates of percentages 73% from total fine aggregates proportion, 2.7% of Polycarboxylate superplasticizer, and around 8% Silica Fume (SF) from total cementitious materials can succeed in reaching high strength concrete with optimum mechanical properties and a noticeable workability improvement when compared to natural aggregates.