Why do we need to use a tamping rod in consolidation of concrete?

Tamping Rods eliminate air voids in concrete when making slump tests, concrete cylinders or conducting concrete air entrainment test. Hemispherically rounded on both ends and plated for corrosion resistance.

What is the size of tamping rod used in tamping concrete sample?

HM-47 Tamping Rod is 12×3/8in (305x10mm) LxDia. It is required for testing in compliance with ASTM C31 as one of the methods of consolidation when molding 4x8in (102x203mm) concrete cylinder specimens.

What is the uses of tamping rod?

Tamping rods are dimensionally accurate rods used to tamp fresh concrete into concrete cylinder molds and grout sample boxes to eliminate voids and excess air.

What are the correct diameter of tamping rod?

Tamping Rod A round straight steel rod 5/8 in. (16 mm) in diameter and approximately 24 in. (610 mm) in length, having the tamping end or both ends rounded to a hemispherical tip, the diameter of which is 5/8 in.

How many times should I Rod concrete?

Rod each layer 25 times throughout the layer depth distributing the roddings uniformly over the cross section. For subsequent layers, penetrate the previous layers about 1 inch. For 6 by 12 inch molds use a 5/8 inch diameter tamping rod and a 3/8 inch diameter rod for 4 by 8 inch molds.

What diameter tamping rod is required for most concrete testing?

3/8″
Tamping Rod must be 3/8″ dia (+/- 1/16-inch) for molds less than 6″ in diameter or width (beam molds). Vibrators must produce at least 9,000 vibrations per minute, and vibrating element must be no bigger than one-fourth the diameter of the cylinder mold or one-fourth the width of the beam mold.

What is the height of tamping rod?

Mold for slump test i.e. slump cone, non porous base plate, measuring scale, temping rod. The mold for the test is in the form of the frustum of a cone having height 30 cm, bottom diameter 20 cm and top diameter 10 cm. The tamping rod is of steel 16 mm diameter and 60cm long and rounded at one end.

What is a concrete tamp?

Tampers (sometimes called Jitterbugs) push the coarse aggregate in the concrete below the concrete surface and consolidate the concrete.

What is the length of tamping rod in CM?

Length : 24”(61 Cm) | Diameter Of Rod : 5/8″ (1.5 Cm). The Slump Cone Tamping Rod/Bar Is Used To Remove Air Pockets When Performing A Slump Test On Concrete.

What causes low strength in concrete?

Two major reasons are: Improper cylinder handling, curing and testing – found to contribute in the majority of low strength results, and. Reduced concrete strength due to an error in production, or the addition of too much water to the concrete on the job due to delays in placement or requests for wet concrete.

How many times do you Rod a concrete beam?

Beams. When rodding beams, fill in: 2 layers (rod once for every 2 sq. in. of top surface area of beam) for beam widths 6 – 8 inches; 3 or more equal layers, layers not to exceed 6″ depth (rod once for every 2 sq.

What happens if concrete slump is too high?

As you increase the amount of water in a mix, you also increase the porosity of the hardened concrete. Excessive slump also can result from accidentally adding too much water-reducing admixtures or super-plasticizers to a mix. This can result in aggregate segregation and a serious loss of strength.

How big is a tamping rod for concrete?

The tamping rod is a round, straight steel rod used with concrete cylinder molds, slump cones, and unit weight tests. Measures 5/8″ diameter by 24″ length. Both ends are rounded to a hemispherical tip. The tamping rod is plated for rust resistance and has a 6″ scale in 1/4″ increments engraved on end of the rod for measuring the slump.

How big is a tamping rod for rust resistance?

The tamping rod is plated for rust resistance and has a 6″ scale in 1/4″ increments engraved on end of the rod for measuring the slump. CAT# TR375. The Cat# TR375 is a 3/8″ diameter by 12″ length, rounded hemispherical tips, less scale. Used primarily on 4″ test cylinders. Meets ASTM C138.

How big is the tamping rod Deslauriers?

Measures 5/8″ diameter by 24″ length. Both ends are rounded to a hemispherical tip. The tamping rod is plated for rust resistance and has a 6″ scale in 1/4″ increments engraved on end of the rod for measuring the slump. The Cat# TR375 is a 3/8″ diameter by 12″ length, rounded hemispherical tips, less scale.

What kind of concrete rods are used for slump cones?

Both models are for use in consolidating 6x12in (152x305mm) concrete cylinder specimens. These rods meet ASTM C143 and AASHTO T 119 standards when testing the workability of fresh concrete with Slump Cones.