Location
University of Leeds
Keywords
Regular strength concrete, high strength concrete, recycled concrete, vibration, consolidation, segregation, durability
Abstract
There is a need for more in depth understanding of the consolidation effect of concrete on its durability, especially in tropical climates. During placement of fresh concrete in molds vibration is required to prevent quality problems such as honeycombs and desegregation. Nevertheless, precise monitoring of concrete vibration time has been avoided by construction professionals. This results in concrete durability reduction of appropriately designed concrete due to variation in aggregate settlement, air void content and change in water to cement ratio. In this study, the effects of vibration time on concrete strength, aggregate segregation, and physical properties were experimentally investigated on regular and high strength recycled concrete. The optimum vibration times are to be determined as a tool for construction professionals to address concrete consolidation issues associated with improper vibration time. The study reports on the test results of regular and high strength recycled concrete with a vibrating table and a rod vibrator for varying vibration times. The result of vibration on the internal structure is also studied as aggregate packing greatly affects concrete durability. It was concluded that an ideal vibration time period for recycled concrete should be based on a combination of concrete properties affecting durability instead of a specific property as vibration of concrete significantly affects concrete strength, porosity, density, viscosity, aggregate segregation, and consolidation. Ideal vibration period for recycled regular and high strength concrete provided the best combination of compressive and splitting tensile strengths, consolidation of aggregate particles, aggregate packing, and air void content to enhance the overall durability of material.
Included in
Characterization of Vibration Effects on the Internal Structure and Strength of Regular and High Strength Recycled Concrete
University of Leeds
There is a need for more in depth understanding of the consolidation effect of concrete on its durability, especially in tropical climates. During placement of fresh concrete in molds vibration is required to prevent quality problems such as honeycombs and desegregation. Nevertheless, precise monitoring of concrete vibration time has been avoided by construction professionals. This results in concrete durability reduction of appropriately designed concrete due to variation in aggregate settlement, air void content and change in water to cement ratio. In this study, the effects of vibration time on concrete strength, aggregate segregation, and physical properties were experimentally investigated on regular and high strength recycled concrete. The optimum vibration times are to be determined as a tool for construction professionals to address concrete consolidation issues associated with improper vibration time. The study reports on the test results of regular and high strength recycled concrete with a vibrating table and a rod vibrator for varying vibration times. The result of vibration on the internal structure is also studied as aggregate packing greatly affects concrete durability. It was concluded that an ideal vibration time period for recycled concrete should be based on a combination of concrete properties affecting durability instead of a specific property as vibration of concrete significantly affects concrete strength, porosity, density, viscosity, aggregate segregation, and consolidation. Ideal vibration period for recycled regular and high strength concrete provided the best combination of compressive and splitting tensile strengths, consolidation of aggregate particles, aggregate packing, and air void content to enhance the overall durability of material.
