The investigation of performance characteristics of reinforced concretes

In this work steel fibres, glass fibres and polypropylene fibres have been used as mixing materials in concrete to investigate. The choosed steel fibres were macrostructured and the other fibres were microstructured. The different combiniations of this fibres in experiments were used to see the effects of different fibres on the mechanical characteristics of fibre reinforced concrete with only one fibre or more fibres. In realized tests the mixing ratios of steel fibres were determined as 0.5, 0.75 and 1 % (in volume per cent). 12 different concrete samples were produced for every experiment groups. The experiment works included the nominations of consistency, unit weight, specific gravity, empty space ratio, water absorption tendency, compressive strength, velocity of ultrasonic pulses, modulus of elasticity, Poisson ratio, bending strength, toughness, impact tests, fatigue tests, shrinkage, freezing and thawing, heat resistance, x-ray scanning photography of microstructure for all concrete samples. The experiments show that the different fibres give them concrete different physical and mechanical characteristics, and the use of mixed fibres in concrete brings any good new properties. Further we realized a questionnaire between concrete producers of City Düzce to determine the fibre employs and their fibre choisses, and also to learn their knowledges about ready mixed concrete experiences. Key Words: Concrete, steel fibres, polypropylene fibres, glass fibres, consistency, unit weight, specific gravity, empty space ratio, water absorption tendency, compressive strength, velocity of ultrasonic pulses, modulus of elasticity, Poisson ratio, bending strength, toughness, impact tests, fatigue tests, shrinkage, freezing and thawing, heat resistance, x-ray scanning photography.