Dynamic Cone Penetrometer (DCP), Dual Mass DCP Hammer with Different Hammer Weights
AMS 300 Dynamic Cone Penetrometer (DCP) with Dual Mass Hammer is a fast and portable field tool that gives you quick and accurate soil shear strength measurements to 6ft (1.8m) deep with option to add extensions for deeper testing. Designed by US Army Corps of Engineers and meets ASTM specs, this DCP is the bridge between lab pavement design and construction quality control. Also used to test structural properties of unbound pavement, DCP testing is portable and quick compared to more complex and bulky cone penetration testing methods.
The DCP measures the soil penetration resistance by a sliding hammer which gives blows per mm. The 1.5 inch diameter cone ensures the energy is not lost to skin friction on the rods. There are two options for driven points: multi-use Hardened Steel or single-use Disposable Cones. The Disposable Cones are left in place so are ideal for situations where extraction would be difficult. Both cones have a maximum diameter of 0.790in (20.1mm) and taper at 60° to a point. The rods can be assembled with quick-connect pin fittings and can go to about 28¼ in (71.8cm) deep. For deeper cone penetration testing, optional extension rods with threaded connections can be purchased separately. The use of different hammer weights in DCP testing is important as it affects the measurements and applications, so you get accurate soil properties.
DCP with Dual Mass Hammer is good for soils with CBR values from 0.5 to 100. In soils with higher strengths the exclusive Dual-Mass Hammer Assembly helps with penetration. This 8kg (17.6lb) Hammer plated drive tube assembly is stainless steel. For soils with CBR values of 10 or less the hammer can be converted to a 4.6kg (10.1lb) unit.
The kit comes in a crush resistant Pelican case with wheels for easy transport. Includes Dual-Mass Hammer plated drive tube assembly, 30in (76.2cm) drive rod, 25 disposable cones with adapter, vertical scale, hardened point, T-handled hex wrench, 3-in-1 oil, Loctite and user’s manual with software and Excel template for DCP data reduction.
Extra disposable cones, heat treated cone adapters and hardened points are available separately. AMS 300 DCP with Dual Mass Hammer meets ASTM D 6951 test
Overall the AMS 300 DCP with Dual Mass Hammer is a tough, portable and accurate tool for quick and precise field measurement of soil shear strength, a must have for construction quality control and pavement design.
The Dynamic Cone Penetrometer (DCP) is a versatile and fast tool for in-situ cone penetration testing of fine grained soils, pavement base courses, sub-bases and soil subgrade layers. This tool gives fast and cost effective soil strength measurement, ideal for shallow pavement designs and foundation bearing capacity and surfaces. DCP is good for fine grained soils and its applications extends to geotechnical engineering, construction and agriculture. By using a heat treated cone to penetrate the soil the DCP is a reliable and widely accepted portable method to evaluate soil properties and ensure construction quality.
History and Development
The concept of dynamic cone penetrometer goes back to ancient times when soil strength and density was measured. The modern dynamic cone penetrometer however has its roots in 17th century when Nicholaus Goldmann developed a ram dynamic cone penetrometer in Germany. Over the years the design and functionality of DCP has evolved. A. J. Scala developed the first modern dynamic cone penetrometer in New Zealand. US Army Corps of Engineers also has been involved in the development and standardization of DCP so it can be used in various applications.
DCP TestEquipment and Operation
The DCP test equipment consists of dual-mass hammer, drive rod and dynamic cone penetrometer. The dual-mass hammer has an 8kg drop hammer with a removable 3.4kg surcharge weight to test a wide range of soils. The drive rod is connected to the dynamic cone penetrometer which is 20mm in diameter and 60° to a point. To perform the test the operator lifts the hammer and lets it free fall, striking the anvil and driving the embedded cone into the soil. Penetration readings are taken after a fixed number of hammer blows, one for soft material, five for typical material and ten for stiff soils. This gives information on soil strength and composition.
Zinc Plated Components
Zinc plated components of DCP test equipment are:
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Dual-mass hammer: 8kg drop hammer with removable 3.4kg surcharge weight for versatility.
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Drive rod: Connected to dynamic cone penetrometer and available in various lengths for different cone penetration testing depths.
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Dynamic cone penetrometer: 20mm diameter with 60° to a point to penetrate the soil and get accurate readings.
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Disposable cones: For situations where extraction would be difficult to get consistent and reliable results.
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Vertical scale: To measure penetration advancement during driving to get soil properties.
Applications and Benefits
DCP has many applications:
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Pavement design and construction: To ensure quality and durability of pavement layers.
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Geotechnical engineering: To get soil analysis and foundation design information.
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Agriculture: For soil compaction testing and land preparation.
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Soil compaction testing: To check soil compaction efforts.
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Foundation bearing capacity surface assessment: To know if soil can support structures.
Benefits of DCP:
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Fast and cost effective soil strength testing: Save time and resources in field testing.
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Fast for fine grained soils: Gives data for various applications.
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Can detect boundaries between pavement layers of different strengths: Ensure correct layer construction.
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Can determine layer thickness: Helps in designing and constructing durable pavements.
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Can evaluate weak soils in road construction: Identify areas that need reinforcement.
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Correlates with California Bearing Ratio (CBR) values: Gives a standardised measure of soil strength for comparison and analysis.
The Dynamic Cone Penetrometer (DCP) is a portable field test method to measure the strength-density of soil in situ. This tool measures the penetration resistance of soil and gives information to geotechnical engineers, construction professionals and researchers. DCP is used to measure soil properties in the field so it’s an essential tool for many applications from pavement design to foundation analysis.
Components and Accessories
The DCP test set includes standard hammer assembly, heat treated dynamic cone penetrometer point with 1ft adapter rod, 30in “E” drill rod extensions, tee handle and operating instructions. The cone is 1.5in (3.8cm) diameter with 45° vertex angle to penetrate the soil. All parts are zinc plated to prevent corrosion for durability and longevity. To collect 3 x 10in (7.6 x 25.4cm) tube samples in hand augured holes the DCP can be used with plated Drive Tube Assembly. Additional accessories to assist with hand augured holes such as sleeved drive hammer sides, disposable cones and cone adapters can be used to increase the versatility of the DCP.
How it Works
The DCP works by a 15lb (6.8kg) steel mass falling 20in (50.8cm) to strike an anvil, driving the embedded cone into the soil. This is done in hand augured holes and the number of blows to drive the cone 1-3/4in is recorded. These blow counts in the hand augured holes are then correlated to N values from the Standard Penetration Test (SPT). The DCP can be used in hand augured holes to depths of 15 to 20ft (4.6 to 6.1m). To collect tube samples the cone can be replaced with a plated Drive Tube Assembly making the DCP a versatile tool for many soil testing applications.
Applications of DCP
The DCP measures the penetration resistance of soil and correlates to Standard Penetration Test (SPT) N values. Its applications are in geotechnical engineering, construction and research where it is used to measure soil properties in the field. When used with an auger test set the DCP measures the strength and density of soil and gives data for pavement design, foundation design and other civil engineering structures. Also the DCP measures soil shear strength which is a critical factor for construction projects stability and safety.
Benefits and Features
The DCP has:
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Quick and easy to use in the field: Time and effort saving.
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Accurate and reliable: Data you can depend on.
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Correlates to Standard Penetration Test (SPT) N values: Standardised for periodic inspection
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Can be used in many types of soil and conditions: Versatile.
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Portable and compact: Easy to transport and store.
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Zinc plated components: Corrosion resistant.
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Sleeved drive hammer sides: Reduces exterior impact zones on the sides.
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Disposable cones and adapters: Convenient.
That’s it.
What is a Dynamic Cone Penetrometer?
A dynamic cone penetrometer (DCP) is a device to test the strength of soils in the field. A simple, hand held tool that measures the penetration of a metal cone into the soil after each hammer blow. The DCP is used to determine underlying soil strength, monitor granular layers and subgrade soils in pavement sections over time and to measure thickness and location of subsurface soil layers. This tool is used to identify weak soils and ensure stability and durability of construction projects. The dynamic cone penetrometer (DCP) is a quick and reliable way to measure soil properties, it’s a must have for geotechnical engineers, construction professionals and researchers.
DCP Test Equipment and Procedure
DCP Test Equipment
The DCP test equipment consists of a steel rod with a conical tip, a hammer and a vertical scale. The rod is 5/8 inch in diameter and the conical tip is 60 degrees. The hammer is 17.6lb (8kg) and is dropped 2.26ft (575mm) to strike the anvil to drive the rod into the soil. The vertical scale is to measure the penetration of the rod after each hammer blow to give precise data on soil resistance and strength.
The DCP Test Procedure
The DCP test procedure is to assemble the test equipment and place it at the test location. First record the penetration of the rod to zero. Raise the hammer to the top of the rod and drop it, drive the rod into the soil. After each hammer blow measure the penetration. Continue the test until the desired penetration depth is reached or the rod penetrates less than 1/8 inch in 10 drops. In cohesive soils, the penetration rod may be slightly rotated to prevent soil binding to get accurate results. This will give you valuable information on soil strength and composition to design and construct stable foundations and pavements.
Applications of DCP
Dynamic cone penetrometers are used in geotechnical engineering for:
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Testing the strength of soils in the field: Get immediate data on soil condition.
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Monitoring granular layers and subgrade soils in pavement sections over time: Long term pavement performance.
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Measuring thickness and location of subsurface soil layers: To understand soil stratification.
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Correlate test results to California Bearing Ratios, in-situ density, resilient modulus and bearing capacity: Standardise soil strength measurement.
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To identify weak soils and determine if stabilization or modification is required: Improve construction safety and stability.
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To estimate the density of a uniform material by relating density to penetration rate on the same material: Quick assessment of soil compaction.
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To measure the density of a material by relating density to penetration rate on the same material: Optimum soil compaction for construction projects.
The DCP is a cost effective and quick way to test soil strength and can be used in pavement design, foundation design and soil stabilization. The test is simple to perform and can be done with minimal equipment and personnel, it’s a must have for geotechnical engineers and construction professionals.