6.8
흐름표 테스트
유동표 시험은 콘크리트의 작업성을 평가하는 데 사용되는 확립된 방법으로, 특히 유동성이 높은 콘크리트 혼합물을 평가하는 데 유용합니다. 이 시험은 강철판으로 덮인 나무판으로 구성된 장치를 사용하는데, 총 무게는 약 15.87kg입니다. 이 판은 힌지를 통해 받침대에 연…
콘크리트의 작업성을 찾고 유동성이 높은 콘크리트를 평가하는 데 사용되는 흐름표 테스트는 총 중량이 35파운드인 강판을 얹은 나무 보드로 구성된 장치를 포함합니다.
힌지는 보드를 베이스에 연결하며 보드의 각 면은 27.6인치입니다.
상부 보드는 1.6인치 높이까지 들어 올릴 수 있도록 설계되었으며 테이블에는 콘크리트를 배치해야 하는 위치를 안내하는 특정 표시가 있습니다.
높이 8인치, 밑면 지름이 8인치, 상단 지름이 5인치인 잘린 원뿔은 콘크리트로 채워져 있습니다. 부드럽게 압축되고 과도한 콘크리트가 제거되며 30초 후에 원뿔 곰팡이가 조심스럽게 제거됩니다.
테이블이 15번 흔들리고 각 충격이 4초 간격으로 주어질 때마다 콘크리트가 퍼집니다.
흔들린 후 측정된 테이블의 두 가장자리에 평행한 퍼짐 정도의 평균은 콘크리트의 작업성을 나타내며, 특정 값은 중간 또는 높은 작업성에 해당합니다.
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Q1: What is the flow table test used for in concrete testing?
The flow table test assesses the workability of concrete, particularly for highly flowable mixes. It measures how easily concrete spreads and flows under controlled jolting, providing data on the concrete's ability to settle under its own weight. This information determines suitability for construction applications requiring high fluidity and even distribution.
Q2: What are the key components of a flow table apparatus?
The flow table apparatus consists of a wooden board topped with a steel plate, weighing 35 pounds total. The board measures 27.6 inches on each side and connects to a base via a hinge. The upper board lifts to 1.6 inches height during testing. A truncated cone mold, 8 inches high with an 8-inch base and 5-inch top diameter, holds the concrete sample.
Q3: How is concrete prepared and placed in the flow table test?
Concrete is placed in the truncated cone mold and gently compacted to ensure uniform density. Excess concrete is carefully cleared away from the top of the mold. After 30 seconds, the cone mold is carefully removed, leaving the concrete sample on the steel plate ready for jolting.
Q4: What happens during the jolting phase of the flow table test?
The table is jolted 15 times at 4-second intervals by lifting the upper board to 1.6 inches and releasing it. Each jolt causes the concrete to spread outward from its initial cone shape. The controlled jolting simulates the effects of vibration during concrete placement in construction applications.
Q5: How is concrete workability determined from flow table test results?
After jolting completes, the extent of concrete spread is measured parallel to the two edges of the table. The average of these two measurements indicates the concrete's workability. Specific spread values categorize the concrete as having medium or high workability, reflecting its flow characteristics.
Q6: Why is measuring concrete spread important for construction?
Measuring concrete spread reveals how well the material flows and distributes under its own weight. This data ensures the concrete meets project requirements for fluidity and even placement. Understanding spread behavior helps prevent segregation and ensures proper concrete consolidation in structural elements.
Q7: How does the flow table test differ from other concrete workability assessments?
The flow table test specifically evaluates highly flowable concrete through controlled jolting and spread measurement. Unlike other workability tests, it simulates vibration effects during placement. This method provides precise quantitative data on concrete flow behavior, making it ideal for self-consolidating and high-performance concrete mixes.