Journal of Materials in Civil Engineering · 2010 · 125 citations · 11 references
EngineeringCivil EngineeringMaterials EngineeringBuilding MaterialsStructural EngineeringStructural MaterialsCementitious MaterialsConcrete MaterialsConcrete TechnologyRecycled Construction MaterialsRecycled MaterialsReinforced Concrete StructuresAggregate Replacement In ConcreteCompressive StrengthConcrete Compressive StrengthElasticityFlexural StrengthFlexural Strength DevelopmentRecycled AggregatesWater-cement Ratio
Recycled aggregate used in concrete frequently contains recycled sand. The study investigates the effects of varying recycled sand content on concrete properties. The authors tested mortars with recycled sand percentages of 0–50 % to assess density, compressive, and flexural strength, and then evaluated concretes (w/c = 0.5) where recycled aggregate was partially replaced by recycled sand. Mortars showed reduced compressive and flexural strength with up to 20 % recycled sand, while concretes with up to 100 % recycled aggregate maintained compressive strength but exhibited decreasing modulus of elasticity, and incorporating up to 10 % recycled sand in the aggregate had no significant impact on either property.
When recycled aggregate is used for concrete manufacture, in many cases these aggregates are accompanied by a recycled sand content. This research focuses on concretes prepared with recycled sand content. First, the research examined the effects of recycled sand content on the characteristics of mortar—density and compressive and flexural strength—by using recycled sand contents of 0, 5, 10, 15, 20, and 50%. Subsequently, the effect on the characteristics of recycled concretes made with a water/cement ratio of 0.50, when part of the recycled aggregate was replaced with recycled sand, was studied. The results obtained on mortars indicate that the use of up to 20% recycled sand caused a drop in the compressive and flexural strength. In concretes, the use of up to 100% recycled aggregate has no appreciable effect on compressive strength but does lower the modulus of elasticity, E, as the recycled aggregate content increases. If the recycled aggregate used in the manufacture of concretes contains up to 10% recycled sand, this sand has no appreciable effect on the compressive strength of the concrete, nor on its modulus of elasticity E.
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