Regenco-Tech - SOIL, ROCK & CONCRETE TESTING

Regenco, LLC - 75 Linwood Street, Bergenfield, NJ - 1(845) 535-1422

Regenco

SOIL, ROCK & CONCRETE TESTING

Regenco has over 20 years of experience performing soil and rock testing in the geotechnical engineering and construction-phase. We are prequalified subcontractor with PANYNJ, NYCDOT and NJDOT. We will soon be validated with USACE. We are an ongoing organizational member of ASTM and participate in technical committee D18 - Soils and Rock.

All sample bags and/or boxes have to be either shipped or dropped off at the specified location; we do not perform pick-ups. Please carefully place sample boxes/jars/bags inside the gray insulated receptacle in front of the roll-up garage door:

Regenco Labs

75 Linwood St.

Bergenfield, New Jersey, 07621

Lab Assignment Sheet - Soils, Rock & Concrete Tests

Download the Lab Assignment Sheet above and assign your lab tests and determine the costs of these tests. For more information and notes on these tests, see below. For valuable insights , click on Design Considerations for Effective Lab Assignment.

Design Considerations for Effective Lab Assignment

⁠Visual Classification of Soil Samples (ASTM D2488) - This is included in most of our tests. We will use the Burmister system of classification as a default, with the Uniform Soil Classification System (USCS) acronym as the supplemental class.

*Client to indicate if the United Stated Department of Agriculture (USDA) Soil Texture Classification is needed, we can include this to the description.

Parameters and other information obtained: Burmister and USCS Classification.

Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis (ASTM D6913) - determine the particle-size distribution (gradation) of soils using a series of standardized sieves, between the 3-inch (75 mm) and No. 200 (75 μm) sieves.

Particles finer than No. 200 sieve is wet washed and removed to ensure accuracy of the granular fraction. If the distribution of fines is needed, a Hydrometer Analysis can be performed.

Parameters and other information obtained: D₁₀, D₃₀, D₆₀, USCS and Burmister Classification. Note: If fines (passing #200 sieve) is more than 10%, D₁₀ cannot be obtained. If fines is more than 30%, both D₁₀ & D₃₀ cannot be obtained. You will need the Hydrometer Analysis below to obtain these data.

Hydrometer Analysis (ASTM D7928) - determine distribution of fines fraction, which includes the silt and clay-sized particles in the soil. This method is based on Stokes' Law, where the terminal velocity of a spherical particle falling through a viscous fluid is directly proportional to the square of its diameter. Thus, the larger fraction of the fine-grained soil settles faster than the smaller particles.

Parameters and other information obtained: D₁₀, D₃₀, D₆₀, USCS and Burmister Classification.

Specific Gravity (ASTM D854) - denoted by GS , is the ratio of the mass of the soil particles to the mass of an equal volume of pure water (de-aired). A dedicated water pycnometer will be used for this test. We will select the most appropriate method:

Dry Preparation: this is for clean, granular soils. This is the standard test.
Wet Preparation: applicable for organic or fine-grained soils.

Parameters and other information obtained: GS.

Liquid Limit, Plastic Limit & Plasticity Index of Soils (Atterberg Limits) (ASTM 4318) - define the moisture states (solid, semi-solid, plastic, and liquid) of fine soil using a Casagrande Liquid Limit machine for the Liquid Limit (LL) and the Thread Rolling methods for the Plastic Limit (PL).

*Shrinkage Limit (SL) determination (ASTM 4943), defines the point where the fine soil sample does not experience further volume change as it is drying. If requested this test, we can include this parameter at the price set in the assignment sheet.

Parameters and other information obtained: LL, PL, PI, SL.

Ash Content & Organic Material of Peat & Other Organic Soils (ASTM D2974) - determine the organic content via Loss on Ignition (LOI). This involves two firing sessions:

Soil sample is dried at 105°C to remove water and establish the oven-dry mass.
The dried soil sample is heated in a muffle furnace to between 440°C and 750°C to effectively burn off all organic material into ash.

Parameters and other information obtained: %organics, ωC.

Moisture Content (ASTM D2216) and Unit Weight (ASTM D7263) - determine the moisture content and unit weight of the granular sample.

Water (Moisture) Content of Soil and Rock by Mass (ASTM D2216) - also known as the water content (ωC), this is the measure of the water fraction of the soil or rock sample. Samples are typically heated to 230 ± 9°F in the oven. Clayey soils will be heated in the oven longer and gradually cooled down.

All samples are cooled inside an airtight container with a desiccant, to prevent reabsorption of ambient moisture in the air). Weighing will also be performed with desiccants in an enclosed analytical balance.

Density and Unit Weight of Soil Specimens (ASTM D7263) - In static geotechnical engineering, unit weight is denoted by ɣt , which represents the bulk weight of the soil mass per unit volume (W/V) with units in lbf/ft3. The dry unit weight (ɣd) is sometimes referred to as the dry density - unless otherwise specified, dry density is mass/volume (ρd).

Parameters and other information obtained: ωC, ɣt, ɣd.

Lab Compaction Characteristics of Soil Using Modified Effort (ASTM D1557) - determine the relationship between soil moisture content and dry unit weight (herein referred to as density) to find the maximum dry density optimum moisture content using the modified effort (56,000 ft-lbf/ft³). The Proctor hammer used for this test weighs 10.0 lbf versus 5.5 lbf for the standard effort (we do not perform standard effort test).

*Client to indicate in assignment if single point curve (faster results) or multipoint curves are needed. Multipoint curves will consists of 4-5 curves at different moisture contents (more accurate).

Parameters and other information obtained: compaction curve/s, ρdmax, ωCo.

One-Dimensional Consolidation (⁠ASTM D2435) - determine the one-dimensional consolidation properties of soils using incremental loading. This test usually applies to compressible soils such as Clays and Organics.

Test results predict the total and differential settlements by recording the time-settlement data during each load increment.

*Client will need to provide:

Sampling Depth
Estimated vertical overburden pressure
Groundwater level (ft)
Expected Design Load - the maximum load we will apply must exceed the expected field stress, typically 4 times greater to achieve overconsolidation. OCR will be calculated:

OCR>1→overconsolidated, OCR=1→normally consolidated, OCR<1→underconsolidated).

The curve we will generate will provide the preconsolidation pressure (Pc ), Compression Index (Cc), Recompression Index (Cr), and the Coefficient of Consolidation (c𝜈).

*Parameters and other information obtained: GS, Pc , Cc, Cr, C⍺ and c𝜈 . Note: Other parameters can be extracted from the provided curve using the Casagrande Method, such as Preconsolidation Pressure (σc') and Current Effective Overburden Stress (σ0').

Triaxial Compression (ASTM D2850, D4767 & D7181) - this test simulates in-situ stresses within the soil at the specific level underground given an applied load. Click on the button above for the correct selection and set-up of these tests.

ASTM D2850 - Unconsolidated Undrained (UU): compress to failure a fully saturated sample without allowing water to drain. Since the soil is not allowed to consolidate under confining pressure and water is not drained during shearing, this test is applicable to rapid, short-term loading conditions. The undrained shear strength is then equal to the undrained cohesion (su = cu). Undrained friction angle (ϕu) = 0 for fully saturated specimens, since pore water takes the load.

Parameters and other information obtained: su or cu.

ASTM D4767 - Consolidated Undrained (CU): Consolidate a fully saturated sample under confining pressure (σ3) with drainage* and then compress (apply deviator stress denoted by σ1) to shear the sample rapidly without drainage. Pore water pressure (denoted by u) is generated during this shearing stage.

*Client to provide to loads to either normally consolidate or overconsolidate the sample.

Parameters and other information obtained: ccu, ϕcu. Note: You can calculate the effective cohesion c' and effective friction angle ϕ' by deducting the pore water pressure u at failure from the total stress (σ' = σ - u) and extracting these parameters from the resulting Mohr circle diagram.

ASTM D7181 - Consolidated Drained (CD): Consolidate a fully saturated sample under confining pressure (σ3) with drainage* and then compress extremely slowly (u = 0) to shear the sample with drainage. the total stress is always equal to the effective stress (σ = σ').

*Client to provide stresses to either normally consolidate or overconsolidate the sample.

Parameters and other information obtained: , u, c', ϕ'

AWWA Corrosion Suite (ANSI/AWWA C105, Appendix A) - establish the corrosivity potential by determining the following:

Soil Resistivity (Soil Box)
pH (pH Meter)
Oxidation-Reduction (Redox) Potential (ORP Probe)
Sulfides (Sodium Azide-Iodine Qualitative Test)
Moisture Content

Parameters and other information obtained: ωC, pH, Ω-cm, mV, sulfide presence, ωC.

Unconfined Compression of Rock (ASTM D7012) - determine the unconfined compression of rock specimens.

Parameters and other information obtained: %organics, ωC.

Compressive Strength of Concrete (ASTM C39/39M) - determine the moisture content and unit weight of the granular sample.

Parameters and other information obtained: %organics, ωC.

DESIGN CONSIDERATIONS FOR EFFECTIVE LAB ASSIGNMENT

One Dimensional Consolidation - There are two methods in the ASTM Standard:

Method A: Uses a constant, standard load-increment duration (24 hours). Time-deformation logs are required on only two of the load increments.

This widely used method provides a combined primary and secondary curve, presenting the Compression Index, (Cc), Recompression Index (Cr) and the Preconsolidation Pressure (σc').

Method B: Requires a continuous time-deformation reading log on every single load increment. We apply the next load increment after the sample passes 100% primary consolidation.

This method applies to critical, time-sensitive projects where the precision of both the rate of settlement - Coefficient of Consolidation (c𝜈) and the rate of Secondary Compression (C⍺) is crucial.

Unconsolidated Undrained (UU) Triaxial Compression - The undrained shear strength parameter represents short-term loading or any other conditions where loads are applied faster than the low-permeability compressible material can drain water.

Embankment Stability: Simulates a rapid construction of an earth dam or highway embankment over soft clay.
Foundation Design: Models a footing's rapidly imposing weight onto a saturated clay layer.
Excavations: Evaluates the immediate, short-term stability of an unsupported open trench or cut slope.

Consolidated Undrained (CU) Triaxial Compression - The undrained shear strength parameter represents sudden loading on consolidated (normal or overconsolidated) soils. Note that u increases in contractive soils (loose sands or soft clays) and decreases in dilative soils (dense sands, overconsolidated clays).

Rapid Drawdown in Dams: Reservoir water level drops quickly. The soil inside the dam remains saturated and cannot drain instantly.
Earthquake Loading: Seismic shaking triggers rapid cyclic loading on a slope or foundation that is consolidated.
Staged Construction: Subsequent stages of construction or backfill consolidates clay underneath, increasing its strength.

Consolidated Drained (CD) Triaxial Compression - this test provides the drained shear strength parameters and simulates long-term loading conditions.

Long-Term Slope Stability of Natural Earth Slopes: Applies to natural embankments and landforms and deep highway cuts, where pore water pressures have effectively dissipated over decades or even centuries.
Deep Excavations and Retaining Walls: Applies to permanent retaining structures in service for a long time. The subsurface soils exhibit steady-state groundwater flow and moisture equilibrium and continues to impart long-term effective lateral pressures against the wall.
Permanent Earth Dams under Steady-State Seepage: Water seeps through the dam at a constant, stable rate according to its specific flow net model.

AWWA Corrosion Suite - A summary of AWWA C105, Appendix A Soil Parameters Ranges with their assigned scores is shown in this table.

Notes:

pH is based on a logarithmic scale with acidity below pH 7 and alkalinity above pH 7.
Results are based on saturated soil box test; in-situ field test results may vary from the lab test results based on the weather and humidity.
Redox potential test measures the electromotive force driving corrosion to the soil. We use ORP /Redox meter with

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