What is the compressive strength of flowable fill?
8.3 MPa
Flowable fill is defined by the American Concrete Institute (ACI) as a self-compacting cementitious material that is in a flowable state at placement and has a compressive strength of 8.3 MPa (1,200 lb/in2) or less at 28 days.
What is the advantage of flowable fill?
Flowable fill is designed to be excavated so it may be easily removed if necessary. It acts like compacted sand and can be excavated with equipment or hand tools. Other advantages are all weather construction and efficient use of materials. Road crews can place flowable fill in rain, snow, or freezing weather.
How far will flowable fill flow?
The higher the water content, the more flowable the mix. Flowability can be measured by one of several different methods, including slump and flow cone tests. The normal slump range for flowable fill mixtures is 150 to 250 mm (6 to 10 in).
How do you test flowable fill?
As described in ASTM D 6024, the test involves dropping a steel ball five times on the surface of the hardened material and measuring the diameter of the impression. If the diameter is 3 inches or less, the material is able to have backfill or pavement placed over it.
How long does it take flowable fill to cure?
Hardening of flowable fill mixes containing 5 percent cement (that is sufficient to support the weight of an average person) can usually be expected in about 1 to 4 hours. Within 24 hours, construction equipment is usually able to move across the surface of the flowable fill without any apparent damage.
Is flowable fill Excavatable?
Flowable fill is intended to contain a low cementitious content for reduced strength development. 6.2. Flowable fill is available in either Excavatable or Non-Excavatable proportions as specified by the Resident Engineer.
How long does it take for flowable fill to harden?
about 1 to 4 hours
Hardening of flowable fill mixes containing 5 percent cement (that is sufficient to support the weight of an average person) can usually be expected in about 1 to 4 hours. Within 24 hours, construction equipment is usually able to move across the surface of the flowable fill without any apparent damage.
What are the ingredients in flowable fill?
Flowable Fill (also known as Controlled Low Strength Material) is a flowable mixture which contains cement, sand, flyash, water and/or foam admixtures. Your local ready-mix producer may suggest mixes varying from these components, depending on their availability and the specified project requirements.
What is the strength of flowable fill?
The late-age strength of removable CLSM materials should be in the range of 30 to 200 psi (0.2 to 1.4 MPa) as measured by compressive strength of cylinders. It is important that the expectation of future excavation of flowable fill material be stated when specifying or ordering the material. WHY is Flowable Fill Used?
What is flowable concrete fill?
Flowable fill is delivered by ready mixed concrete truck mixers and placed easily by chute in a flowable condition directly into the cavity to be filled. To avoid segregation, the drum should be kept agitating.
What is the minimum compressive strength of concrete?
It hardens into a strong material with minimal subsidence. While the broader definition includes materials with compressive strength less than 1200 psi (8.3 MPa), most applications use mixtures with strength less than 300 psi (2.1 MPa).
What is an excavatable flowable fill mixture?
The National Ready Mixed Concrete Association defines an “excavatable” flowable fill mixture as one with a compressive strength not exceeding 150 pounds per square inch. Mixtures exceeding this strength have also been known to be excavatable with the use of mechanical equipment.