What is CBR Test in Civil

What is CBR Test?

How to CBR Test Complete?

Read more

Apparatus Required for CBR Test

  1. Inside diameter of 150mm and height of 175mm with a separable perforated base plate of 10mm thickness and 235mm diameter.
  2. It has a net capacity of 2250 ml, meeting the requirements of IS-9669:1980.
  3. There is one detachable extension collar with 60 mm height, Spacer Disc with 148 mm diameter, and height of 47.7 mm along with the handle.
  4. Furthermore, several slotted weights weighing 2.5 kg each weight and single annular metal weight and, 147 mm in diameter, with a hole in the center of 53 mm in diameter.
  5. In this test, the height of the drop is 450 mm for compaction Rammer, and its weight is 4.89 kg.
Read more

Step up ApparatusΒ for CBR Test

  1. Lubricating oil is applied in the internal surface of the mould to make it frictionless removals of soil.
  2. Start compacting the mixed soil in the mould by helping bit heavy compaction. i.e.By using 4.89 kg rammer, compact the soil in 5 layers with 55 blows to each segment.
  3. Afterward, remove the extension collar and level and trim the compacted soil carefully at the topmost level of mould or leveling of the top surface.
  4. In case if there are any voids developed on the top surface of the compacted soil after removal of the coarse material, all voids refilled by using smaller particles of soil material.
  5. The next step is to measure the weight of the compacted soil specimen and mass of the mould, after removing the perforated base plate, Spacer disc, and filter paper.
  6. Put this filter paper on the base plate and reverse the mould and remove the compacted soil. Hence this soil came in contact with the filter paper.
  7. Set a filter paper above the specimen, on the other hand, place a perforated plate on top of the compacted soil specimen in the mould.
  8. Lay annular weights to generate a surcharge equivalent to the weight of base material and pavement, to the nearby 2.5 kg.
  9. Now, submerge the mould assembly and weights into a tank of water and saturate it up to 96 hours. Set the stand for expansion measuring device on the edge of the mould, record preliminary dial gauge reading.
  10. The second step is to Note down the readings every day adjacent to the time of reading. Make sure that the water level shall remain constant to maintained in the tank right through the period.
  11. Final step or at the end of the soaking period, parallel note down the last reading of the dial gauge and get the mould out from the water tank.
  12. Take out the extra water collected in the mould and allocate the specimen to draw off for 15 minutes. At last, Remove the perforated plate and the filter paper from the top layer, evaluate the soaked soil sample and record the weight.
Read more

The Procedure ApparatusΒ for CBR Test

  1. Firstly, set the mould assembly with a test specimen on the lower plate of the penetration testing machine.
  2. For avoiding disruption of soil into the hole of the extra weights, 2.5 kg annular pressure shall be sited. Before setting out surcharge weight placed on the soil surface, first to set the penetration plunger.
  3. The penetration piston is set at the middle of the specimen with the nominal possible load; however, in some cases, over 4 kg, thus full contact of the piston on the pattern, is established.
  4. Set the weight on it, so deformation gauges are to be read zero, by applying the load on the piston hence the penetration rate is nearly 1.25 mm/min.note down all load readings at penetrations of 0.5, 1.0, 1.5, 2.0, 2.5, 4.0, 5.0, 7.5, 10 and 12.5 mm.
  5. Pull up the plunger and separate the mould from the loading equipment.
  6. Afterward, Take out 20 to 50 g of soil from the top 30 mm layer and find out the moisture content.
Read more

The Calculation Required During the Experiment:

Penetration(mm)Standard Load(kg)Unit Standard Load(kg/cm2)
2.5137070
52055105
7.52630134
103180162
12.53600183
Read more

Standard Load Values for CBR Test

  • C.B.R. value at 2.5 mm penetration = 3.
  • Β C.B.R. value at 5.0 mm penetration = 4.
Read more

What Is a CBR?

What Is a CBR Test Used For?

Read more

How Is CBR Value Calculated?

California Bearing Ratio Values

Read more

CBR Value

CBR Test Procedure

Read more

How to Calculate CBR?

CBR Test Procedure for Civil Engineering

Read more
  • Sample collection
  • Sample preparation
  • Specimen soaking
  • Sample compaction
  • Installation of penetration plunger
  • Loading setup
  • Application of vertical load
  • Load vs. penetration measurement
  • CBR calculation
  • Reporting
Read more

CBR Test Equipment Suppliers in USA

  • Humboldt Mfg. Co.
  • Gilson Company, Inc.
  • Controls Group USA
  • ELE International
  • Cooper Technology
  • M&L Testing Equipment, Inc.
  • Karol-Warner
  • Forney LP
  • Geocomp Corporation
  • PCTE - Pine Test Equipment, Inc.
Read more

CBR Test Specifications and Standards

  • Test Equipment
  • Sample Preparation
  • Test Procedure
  • Calculation and Reporting
Read more

CBR Test Cost for Civil Engineering Projects

CBR Test Report Format and Interpretation

Read more
  • Title and Test Information
  • Introduction
  • Test Procedure
  • Test Results
  • Discussion
  • Conclusion
  • References
Read more

CBR Full Form in Civil Engineering

CBR in Civil Engineering

Read more

CBR Method

In CBR Test the Value of Cbr Is Calculated At?

Read more

CBR Test of Soil

What Is CBR Value?

Read more

Why CBR Test Is Done?

  • Subgrade Evaluation
  • Pavement Design
  • Material Selection
  • Quality Control
  • Research and Development
Read more

What Is CBR in Road Construction?

  • Plate Loading Test
  • Top 10 Cement Companies in USA
  • Top 10 Construction Companies in the USA
  • Top 10 Construction Companies in India
  • Top 10 Best Cement Companies In India 2021
  • Test for Compressive Strength of Brick | Water Absorption | Dimensions Test
  • First Angle Projection & Third Angle Projection Symbol (Orthographic Projection)
  • What Is Lap Length | Lap Length of Column | Lap Length of Slab | Lap Length of Beam
Read more

Did you like this story?

Please share by clicking this button!

Visit our site and see all other available articles!

Civil-Jungles