What is CDF slurry?
Flowable fill is sometimes referred to as controlled density fill (CDF), controlled low strength material (CLSM), lean concrete slurry, and unshrinkable fill.
How long does it take for controlled density 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.
How much does CLSM cost?
A cost comparison of CLSM and conventional backfill (manufactured limestone sand) indicates that when trench dimensions are the same and only direct costs (labor, materials, equipment, and associated costs) are included, CLSM costs approximately $9.50 per foot of pipe more than conventional backfill for a six-foot by …
Does flowable fill get hard?
In terms of its flowability, the slump, as measured for concrete, is generally greater than 8 inches (200 mm). It is self-leveling material and can be placed with minimal effort and does not require vibration or tamping. It hardens into a strong material with minimal subsidence.
What is CDF fill?
1.01 DESCRIPTION Control Density Fill (CDF) is used as a low strength, self consolidating fill material for confined spaces which can be easily excavatable at a later time. CDF is characterized by a high maximum slump of 8 inches. CDF is not a structural concrete and should not be used in such applications.
What is slurry Backfill?
Page 1. NATIVE SLURRY BACKFILL is a predictable and precise structural. backfill material that uses native on-‐site material mixed with. cement and water to create a performance backfill. Native Slurry Backfill (NSB) is a controlled low-‐strength material (CLSM) utilizing the on-‐site soils.
What is CDF concrete?
What is control density fill?
How do you calculate flow fill?
Calculate the volume of the trench by using this formula: Volume = Width x Length x Depth. As an example, a trench 12 feet long with an average width of 2.3 feet and an average depth of 5 feet has a volume equal to (12 x 2.3 x 5), or 138 cubic feet.
How thick can you pour flowable fill?
Maximum lift thickness shall be three (3) feet, except where such thickness would cause lifting or displacement of the utility, pipe or structure. In such case, depth of flowable fill shall be limited to prevent displacement of the utility, pipe or structures.
What is CDF in construction?
What PSI is flowable fill?
Flowable fill is defined as a material with compressive strength less than 1200 psi (8.3 MPa). Most applications, however, use mixtures with strength less than 300 psi (2.1 MPa). The ability to excavate flowable fill will depend on the equipment used for the strength and type of mixture placed.