What is Unshrinkable fill?
Unshrinkable Fill: means a mixture of aggregates, cementing material and water, with or without chemical admixtures, that hardens into a material with higher strength than soil but less than 0.4 Mpa compressive strength at 28 days, that can be removed with hand tools.
Is flowable fill permeable?
Flowable fill has a higher load-carrying capacity than those of compacted soil or granular fill. It is less permeable and can be designed to achieve compressive strengths up to 1,200 psi.
Is CLSM considered concrete?
CLSM should not be considered, and in-turn tested, as a type of low strength concrete. Instead, CLSM should be considered as a self compacting and self leveling backfill material that is used in lieu of compacted fill.
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.
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).
What is the unit weight of flowable fill?
between 70 and 145 pounds per cubic foot
The unit weight of flowable fill mixtures typically ranges between 70 and 145 pounds per cubic foot. However, the use of special chemical admixtures for flowable fill mixtures can reduce the unit weight to as low as 20 pounds per cubic foot for applications requiring minimal loading conditions.
What is the difference between flowable fill and concrete?
Flowable fill is a self-compacting low strength material with a flowable consistency that is used as an economical fill or backfill material as an alternative to compacted granular fill. Flowable fill is not concrete, nor it is used to replace concrete.
Is CLSM a flowable fill?
Controlled low strength material, abbreviated CLSM, also known as flowable fill, is a type of weak, runny concrete mix used in construction for non-structural purposes such as backfill or road bases.
What is CLSM used for?
A controlled low-strength material (CLSM) is a self-consolidating, cementing material used primarily as a backfill as an alternative to compacted fill.
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.
What is the difference between flowable fill and lean concrete?
Both lean and flowable concrete can be used to fill sub-bases and sub footing as well as abandoned wells and cavities, however, flowable concrete is more associated with backfill projects in which concrete will be removed soon after the project is completed.
How many PSI is lean concrete?
Lean concrete base (LCB) is made with concrete aggregate and sufficient cement (about three sacks) to achieve a strength of at 500 psi (3.5 MPa) in seven days. Mix design, testing, and inspection are handled the same as with concrete paving.
What does CLSM stand for?
What is slurry fill?
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 the grade of DLC?
Cement And Aggregate Dry Lean Concrete, Grade Standard: M50
| Grade Standard | M5 To M7.5 |
|---|---|
| Material | Cement and Aggregate |
| Density | 2450 Kg/m3 |
| Application | Sub Base/Bedding |
| Packaging Type | Loose Material |
How long does it take flowable fill to cure?
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.
How do you calculate slurry backfill?
For example, find the cubic footage volume of a backfill area that is 8 feet wide, 6 feet deep and 50 feet long. The volume of a rectangular cubed shape is found by the formula v = l x w x d, where v represents volume, l is the length of the trench, w is the width and d is the depth.
What is the purpose of flow fill?
Flowable fill refers to a cementitious slurry consisting of a mixture of fine aggregate or filler, water, and cementitious material(s), which is used primarily as a backfill in lieu of compacted earth.
What is the density of DLC?
DLC has many possible material properties as it becomes more diamond like and crystalline. Its density is between graphite and diamond (2.2-3.5 grams/cubic centimeter).
What is difference between DLC and PQC?
PQC stands for Pavement Quality Concrete made with larger size aggregates following IRC specifications and laid over a Dry Lean Concrete(DLC) sub-base. PQC construction is explicitly used for highway concrete pavements and runway pavements to take heavy loads.
How do you calculate backfill?
The volume of a rectangular cubed shape is found by the formula v = l x w x d, where v represents volume, l is the length of the trench, w is the width and d is the depth. Applying the numbers to this formula (8x 50x 6) the cubic footage of the example area is 2400 cubic feet.
How do you calculate fill volume?
The volume between each pair of sections is estimated by multiplying the average cut or fill area of the two sections by the distance between them. Once these volumes have been calculated for each pair of sections the total cut and fill volumes are obtained by adding them all together.
What is the advantage of flowable fill?
Flowable fill allows narrower trenches because it eliminates having to widen trenches to accommodate compaction equipment and laborers in the trench. Unlike soil or granular backfill, flowable fill can be placed without rollers, loaders, or tampers.
How do you measure flowable fill?
Calculate flowable fill as you would for filling a trench or space with concrete. Measure the length of the entire space. Then measure the width and depth/height at several points along the trench or space you need to fill.
What is the ratio of PQC?
0.40
A control mix for PQC was prepared with 400 kg/m3 of ordinary Portland cement (OPC) and water–cement (w–c) ratio of 0.40.