The CBR bearing ratio tester is suitable for carrying out bearing ratio tests on various soil and mixtures (soil with a particle size less than 40mm) after being compacted in a specified test cylinder mold to determine the bearing capacity of the designed road surface, road base, subbase, and roadbed material layer. The instrument consists of a host, a force measuring ring, a penetration rod, an additional planting plate, a percentage gauge, and an expansion measurement device. The instrument has the characteristics of small size, high output, and easy operation.
The CBR load ratio testing machine is suitable for conducting load ratio tests on various soil and mixtures (soil with a particle size less than 40mm) after compaction in a specified cylindrical mold to determine the bearing capacity of the designed pavement, pavement base, subbase, and subgrade material layers. The instrument consists of a host, a force ring, a penetration rod, a planting plate, a dial gauge, and an expansion measurement device. This instrument has the characteristics of small volume, large output, and easy operation.
Main parameters of CBR bearing ratio tester:
★ Speed: 1mm/min, high pressure 3T
★ Penetration rod: end face diameter φ 50mm. internal diameter φ 52mm long 100mm
★ Perforated plate: two pieces
★ Dial gauge: 0-10mm, three pieces φ
★ Load plate: 6 pieces (outer diameter φ 150mm, inner diameter φ 52mm, each 1.25Kg)
★ Test cylinder: inner diameter φ 125mm, 170mm high, cushion block φ 151mm, height 50mm, same as heavy compaction test cylinder.
★ Overall dimensions: 310X310X930mm
★ Weight: 100kg
Main parameters of CBR load ratio tester:
★ Speed: 1mm/min Multi pressure 3T
★ Through rod: End face diameter φ 50mm. 100mm long inner diameter φ 52mm
★ Perforated plate: two pieces
★ Dial gauge: 0-10mm, three φ
★ Load plate: 6 pieces (outer diameter φ 150mm, inner diameter φ 52mm, each 1.25kg).
★ Cylinder: Inner diameter φ 125mm, 170mm high, gasket φ 151mm, height 50mm. Same as heavy compaction test cylinder.
★ Overall dimensions: 310X310X930mm
★ Weight: 100kg
Usage method of CBR bearing ratio tester:
★ Turn on the power switch, operate the instrument, check if the working condition of the instrument is normal, check if the handle is in and out, and rotate normally. If everything is normal, prepare to start the test.
Prepare test specimens according to the “Test Specification for Highway Pavement Base Materials” JTJ075-85 Bearing Ratio Test Method.
★ Measurement of saturation expansion:
★ Measurement of saturated expansion: Place the test piece that has undergone moisture curing on a porous plate equipped with an adjustment rod, and add sufficient load plates on the plate to ensure that the pressure on the surface of the test piece is equal to the pressure on the road surface of the material layer,
★ Place the test tube and porous plate together in the sink (without draining water) and tighten the mold with a pull rod. Install a dial gauge and take the initial reading.
★ Drain water into the sink to allow it to freely enter the top of the specimen. During the period of saturation, the water in the sink should be kept 25mm above the top surface of the specimen, usually soaking for 96 hours,
At the end of the soaking time, read the dial gauge reading and calculate the expansion amount.
=Change in specimen height after soaking/original specimen height (120mm) ×**
★ Take out the sample from the sink, pour out the water on the sample, let it stand for 15 minutes to drain, then remove the additional load, porous plate, bottom plate, and filter paper, and bear the load M to calculate the depth and density changes of the sample.
★ Penetration test: Place the specimen after the saturated water test on the lifting plate of the tester, adjust the alignment between the penetration rod and the force measuring ring, and place a predetermined number of load plates around the penetration rod.
Firstly, apply a 45N load to the penetration rod using a handwheel, and then adjust the force measuring ring and deformation measuring dial gauge to zero.