Fabrication of High Strength Concrete from Recycled Concrete Aggregate Utilizing Taguchi Method

摘要

The preparation of concrete mixtures can be tailored to provide wide range of mechanical and durability properties as well as to meet the design specifications of the structure. This paper discusses the potential use of recycled concrete aggregate in the production of high strength concrete. The effect of other processing parameters such as aggregate replacement ratio, type of admixture and slump height on the compressive strength and water absorption rate of different concrete mixes were investigated. The fabrication of high strength concrete was done by machine-mixing of the aggregates, Portland cement and admixture in accordance with ASTM C192, utilizing the Taguchi design to derive the concrete mixtures. Using the 10% recycled fine aggregate with Mira P99 admixture and slump height of 4-6 inches showed an optimum condition and yielded a predicted maximum compressive strength at around 8400 psi. The failure mode of the concrete after compression test was generally shear fracture type. For the water absorption rate, only the admixture had a significant effect. Surface morphology of the fractured concrete surface revealed that utilizing recycled concrete aggregate resulted to a porous surface morphology compared to the natural aggregate.