bulk specific gravity of soil formula bulk specific gravity of soil formula

The calculation should then be: SG = Ps/Pw Find The Soil Testing Equipment You Need At Certified MTP Calculation Examples. V = Volume of the Soil = 6. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Gs =Unit weight (or density) of soil sample only / Unit weight (or density) or water. Android (Free)https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator Although it avoids problems associated with the SSD condition, it is often inaccurate because it assumes a perfectly smooth surface, thereby ignoring surface irregularities (i.e., the rough surface texture of a typical specimen). Each one uses a slightly different way to determine specimen volume and may result in different bulk specific gravity values. Stop when the cap of the barrel is flush with the soil surface. Legal. The formula for bulk density is (mass of dry soil) / (total volume of soil), 1 - (bulk density/particle density) for porosity, and (volume of pores) / (volume of solids) for void ratio.. Ps = Ms/ (500-Vw) Now that you have the density of soil solids, you can calculate the specific gravity of soil solids (SG). Determine water content within a soil sample as a percentage, by drying the soil in the oven at 105oC for 24 hours. So, be careful if the question is like that; derive the relation between bulk density, dry density and water content, therefore, the answer will be same.] This discards small aggregate particles clinging to the retained large particles. UNIT WEIGHT OF SOIL SOLIDS (? For instance, deleterious particles (Figure 2) are often lighter than aggregate particles and therefore, a large amount of deleterious material in an aggregate sample may result in an abnormally low specific gravity. Soils are composed of a combination of solids (soil particles), liquids (soil water), and gases (soil atmosphere). Your answer should be 1.5 g/cm 3. \ (\mathrm {Gm}=\frac {\text { Weight of soil of given soil }} {\text { weight of standard fluid of same volume }}\) (d)max = dry unit weight of the soil at its densest condition, Designation of Granular Soil Based on Relative Density. INSTRUCTIONS: Choose units and enter the following: () The mean density of the object or liquid. In this laboratory, additional physical properties will be measured, and their implications for land management will be discussed. Specific gravity of solid = 2.65. Particle density is a measure of the mass of soil solids per given volume (g/cm3 ); however, pore space is not included as it is with bulk density. Engineering Civil Engineering A sand sample has a bulk density of 20kN/m and a degree of saturation of 70%. s /? Correct and accurate material specific gravity determinations are vital to proper mix design. Write a mathematical expression for these relationships. The value of specific gravity (soil) varies between 2.65-2.80. The usual standard of comparison for solids and liquids is water at 4 C (39.2 F), which has a density of 1.0 kg per litre (62.4 pounds per cubic foot). Typically, aggregate used in HMA production will have an absorption between just above zero and 5 percent. ASTM D 2726: Bulk Specific Gravity and Density of Non-Absorptive Compacted Bituminous Mixtures, AASHTO T 166: Bulk Specific Gravity of Compacted, AASHTO T 275: Bulk Specific Gravity of Compacted Bituminous Mixtures Using Paraffin-Coated Specimens, AASHTO TP 69: Bulk Specific Gravity and Density of Compacted Asphalt Mixtures Using Automatic Vacuum Sealing Method. Using the recommended reading and viewing resources and the introduction to this lab, answer the questions listed below. Learn specific gravity, Absolute or true specific gravity, Table of specific gravity of soil constituent. You can get this app via any of these means: Webhttps://www.nickzom.org/calculator-plus, To get access to theprofessionalversion via web, you need toregisterandsubscribeforNGN 2,000perannumto have utter access to all functionalities. Use a soil spatula to level the top of the sample in the graduated cylinder and add soil with the spatula until the top of the soil sample is exactly even with the 50 mL line this is the bulk volume of compacted soil (B) (1 mL = 1 cm3 ). The difference between Gsa, Gse and Gsb is the volume of aggregate used in the calculations. The coarse aggregate specific gravity test measures coarse aggregate weight under three different sample conditions: Using these three weights and their relationships, a samples apparent specific gravity, bulk specific gravity and bulk SSD specific gravity as well as absorption can be calculated. Laboratory samples are typically dry at the beginning of the test; however, field samples will typically be damp. Calculating the Mass of the Soil when the Bulk Density and the Volume of the Soil is Given. emax = void ratio of the soil at its loosest condition It is an important parameter in soil mechanics for the calculation of the weight-volume relationship. This results in less total pore volume. Find the specific gravity of soil particle when the density of water is 22 and the the density of soil is 11. w = Density of Water = 22 Remember, the volume of the water displaced is equal to the volume of the. Several important physical properties have been discussed in other labs: texture, structure, color, and consistency. What are the sizes of macropores and micropores? Android (Paid)https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator Gently stir soil/water mixture to remove any air bubbles. For a particular aggregate type or source, fine aggregate specific gravities can be slightly higher than coarse aggregate specific gravities because as the aggregate particles get smaller, the fraction of pores exposed to the aggregate surface (and thus excluded from the specific gravity calculation because they are water-permeable) increases. Use a vacuum pump to gradually apply vacuum and remove the entrapped air while spinning the flask to remove the air bubbles. You must have JavaScript enabled to use this form. Though not critical, it is important that we know it. A soil sample has a dry density of 8.5 kN/m 3, specific gravity of solids G as 2.7 and voids ratio of 0.6. This is because in the normal procedure the water may not be able to penetrate the pores to the center of the aggregate particle during the soaking time. The formula for calculating bulk density: sb= Bulk Density Calculate the specific gravity of the soil solids using the following formula: Specific Gravity (G s) = W o / (W o + (W a - W b )) W o = Weight of sample of oven-dry soil, g = W ps - W p. W a = Weight of Pycnometer filled with water. Water Content or Moisture Content, w The following formulas are taken from unit weights of soil: = ( G + S e) w 1 + e = ( G + G w) w 1 + e d = G w 1 + e s a t = ( G + e) w 1 + e = ( G 1) w 1 + e Where m = mass of soil V = volume of soil W = weight of soil = density of soil d = dry density of soil sat = saturated density of soil ' = buoyant density of soil d = =17.857Kn/m3 17.857= Therefore, texture and structure govern the amount of soil pore space. Take an average of 3 values these values should not vary by more than 2 to 3%. V = Total volume of the given soil mass. Your email address will not be published. The specific weight, , of a material is defined as the product of its density, , and the standard gravity, g: =g{\displaystyle \gamma =\rho \,g} The densityof the material is defined as massper unit volume, typically measured in kg/m3. These two (water and air) are called voids which occupy between soil particles. Equation for calculate bulk specific gravity is, G b = (W * D) / (W - I) Where, G b > = Bulk Specific Gravity. High bulk density soils are soils with little pore space, so water infiltration is reduced, root penetration is inhibited, and aeration is restricted reducing agricultural productivity. Bulk density of a soil refers to the mass of a volume of dry soil. Unit weight, $\gamma = s \gamma_w$, Specific gravity, $s = \dfrac{\gamma}{\gamma_w}$, Physical Properties The difference between Gsa and Gsb is the volume of aggregate used in the calculations. Types: Absolute specific gravity Bulk specific gravity/apparent specific gravity Upon completion of this exercise you should be able to: From Brady and Weil, The Nature and Properties of Soils, 13 th Ed. Find the bulk density when the mass of the soil is 24 and the volume of the soil is 6. m = Mass of the Soil = 24 The specific gravity G of the soil = (W 2 - W 1) / [(W 4 - 1)-(W 3-W 2)] The specific gravity should be calculated at a temperature of 27 o C and reported to the nearest 0.01. These two (water and air) are called voids which occupy between soil particles. Slowly pour approximately 25 mL of soil sample from beaker into water in the graduated cylinder. One critical problem with this method is that if a specimens air voids are high, and thus potentially interconnected (for dense-graded HMA this occurs at about 8 to 10 percent air voids), water quickly drains out of them as the specimen is removed from its water bath, which results in an erroneously low HMA sample volume measurement and thus an erroneously high bulk specific gravity. Lets solve an example; Dry specimen to a constant mass and cool to room temperature. Accessed 1 July 2002. Some lightweight shales (not used in HMA production) can have absorptions approaching 30 percent, while other aggregate types can have near zero absorption. First of all, we need to kind the density of the object. Determine the weight of dry soil in the sample. Saturated surface-dry (SSD, water fills the aggregate pores). Unit weight is the weight of soil per unit volume. Water Density (23C) =0.9993 (Table-3) . Weight of soil mass at moist condition: 56.6 kg. Porosity is the ratio of volume of voids to the total volume of soil. Calculating the Density of Soil when the Specific Gravity of Soil Particle and the Density of Water is Given. Bulk specific gravity is involved in most key mix design calculations including air voids, VMA and, indirectly, VFA. The gamma ray method is based on the scattering and absorption properties of gamma rays with matter. Read More: 7 Brick Test to Decide Quality of Bricks. This laboratory entails a demonstration of the use of a soil density sampler, and a problem set that is focused on common soil density calculations. Data Analysis. Selected Topics. It is the Specific Gravity of Soil. Absorption, which is also determined by the same test procedure, is a measure of the amount of water that an aggregate can absorb into its pore structure. As mentioned in the background section, if a specimens air voids are high, and thus potentially interconnected (for dense-graded HMA this occurs at about 8 to 10 percent air voids), water quickly drains out of them as the specimen is removed from its water bath, which results in an erroneously low SSD weight, which leads to an erroneously low HMA sample volume measurement and thus an erroneously high bulk specific gravity. V = Volume of the Soil. $V_v = V_w + V_a$, total weight = weight of solids + weight of water sb= Bulk Density However, of specific concern is the mass of the SSD sample. HMA bulk specific gravity is needed to determine weight-volume relationships and to calculate various volume-related quantities such as air voids and voids in mineral aggregate (VMA). Aggregate specific gravity is used in a number of applications including Superpave mix design, deleterious particle indentification and separation, and material property change identification. Once there are no visible signs of water film on the aggregate particle surfaces, determine the sample mass. Typically, aggregate used in HMA production will have a bulk specific gravity between about 2.400 and 3.000 with 2.700 being fairly typical of limestone. w= Density of Water A unit called the slug , equal to 32.17 "mass-pounds" or 14.6 kg, can be used to convert between pounds in the . Dry unit weight is the weight of dry soil per unit volume. Relation Between Void Ratio, Water Content, Degree of Saturation & Specific Gravity In this article, we will make a formula or equation or relation between void ratio (e), water content (w), degree of saturation () and specific gravity (G). Specific gravity is a unitless measurement of a sample's density relative to water. The degree of saturation is normally expressed in a percentage. V = Volume of the Soil Dry Mass Density The bulk specific gravity test measures a HMA samples weight under three different conditions (Figure 1): Using these three weights and their relationships, a samples apparent specific gravity, bulk specific gravity and bulk SSD specific gravity as well as absorption can be calculated. Weigh and record graduated cylinder plus compact soil weight (C). ( w) The mean density of water (default is 1,000 kg/m 3) Compact the soil by dropping onto a padded surface like a book, notebook, etc. A quick check of the results should show that bulk specific gravity is the lowest specific gravity, bulk SSD specific gravity is in the middle and apparent specific gravity is the highest. They are also useful as study notes for exams. If absorption is incorrectly accounted for, the resulting HMA could be overly dry and have low durability (absorption calculated lower than it actually is) or over-asphalted and susceptible to distortion and rutting (absorption calculated higher than it actually is). Plasticity index, $PI = LL - PL$, Liquidity index, $LI = \dfrac{MC - PL}{PI}$, Activity of clay, $A_c = \dfrac{PI}{\mu}$, where $\mu$ = soil finer than 0.002 mm in percent, Other Formulas Return any soil sample remaining in beaker to sample storage container and dry clean beaker. To compute for bulk density, two essential parameters are needed and these parameters areMass of the soil (m)andVolume of the soil (V). 3-1. The total pore space consists of the voids between sand, silt, and clay particles and voids between soil aggregates. In practice, the paraffin is difficult to correctly apply and test results are somewhat inconsistent. It is often found that the specific gravity of the materials making up the soil particles are close to the value for quartz, that is Gs 2.65 For all the common soil forming minerals 2.5 < Gs < 2.8 We can use Gs to calculate the density or unit weight of the solid particles s = Gs w s = Gs w Bulk SSD specific gravities can be on the order of 0.050 to 0.100 higher than bulk oven dry specific gravities, while apparent specific gravities can be 0.050 to 0.100 higher still. Android (Free)https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator Place the core into a labeled, pre-weighed canister, and put on the lid. The procedure that is followed towards that goal is the following: To better understand how the Specific Gravity is calculated, the aforementioned measured quantities are presented in Figure 1. $\gamma_s = G\gamma_w$, $\dfrac{W_s}{V_s} \cdot \dfrac{W_w}{W_w} = G\gamma_w$, $\dfrac{W_w}{V_s} \cdot \dfrac{W_s}{W_w} = G\gamma_w$, $\dfrac{W_w}{V_s} \cdot \dfrac{1}{W_w/W_s} = G\gamma_w$, $\dfrac{\gamma_w V_w}{V_s} \cdot \dfrac{1}{w} = G\gamma_w$, $\dfrac{V_w}{V_s} \cdot \dfrac{1}{w} = G$, $\dfrac{V_w}{V_s} \cdot \dfrac{V_v}{V_v} = Gw$, $\dfrac{V_w}{V_v} \cdot \dfrac{V_v}{V_s} = Gw$. Find the mass of the soil when the bulk density is 10 and the volume of the soil is 4. sb = Bulk Density = 10 w = Water content or moisture content Shake the container to release any entrapped air before weighing. This lab is performed to determine the specific gravity of soil by using a pycnometer. The difference in weights can then be used to calculate the weight of water displaced, which can be converted to a volume using the specific gravity of water. Figure 8: The basket used for underwater weighing. Find the density of water? The screenshot below displays the page or activity to enter your values, to get the answer for the specific gravity of soil particle according to the respective parameters which is the Density of water (w)andDensity of soil (s). The container overflow needs to work properly to compensate for the water displaced by the sample. Absorption can indicate the amount of asphalt binder the aggregate will absorb. For example, if spherical (r = radius and = density) . Obtain a sample of coarse aggregate material retained on the No. The density of water varies less than 1.5 mg/cm3 over the narrow range of normal temperatures. The results are as follows: Aggregate A: Bulk specific gravity=2.814; absorption=0.4% Aggregate B: Bulk specific gravity=2.441; absorption=3.0% What is the specific gravity of a mixture of 35% aggregate A and 65% aggregate B by weight? Q.2: Why unit weight of water is taken at 4C. The specific gravity (G S) of a soil refers to the ratio of the solid particles' unit weight to the unit weight of water. Posted by Dinesh on 21-07-2021T12:27. Given that the specific gravity of soil particle is 12 and the density of soil is 156. The specific gravity of solids, G is determined using following equation: G= (M2-M1)/[(M2-M1)-(M3-M4)] Where M 1 = mass of empty pycnometer M 2 = mass of pycnometer and dry soil M 3 = mass of pycnometer, soil, and water M 4 = mass of pycnometer filled with water only. Note that total volume of the soil sample equals the volume of the solids and the volume of the pores. Now, Click on Soil Mechanics and Foundation underAgricultural, Now, Click on Bulk Density underSoil Mechanics and Foundation. Although the Test Description section describes the standard AASHTO T 166 saturated surface dry (SSD) water displacement method, there are a number of other methods available. G S should not be confused with the soil density since it is a dimensionless unit and expresses the ratio of two particular densities. s= Density of Soil On oven drying, the density drops to 1.74 gm/cc. Bulk specific gravity (Gmb) and the percentage of water absorbed by volume. Those flows are dependent on soil porosity and pore connectivity. The above values have been provided with both imperial and metric units. From $\gamma = \dfrac{(G + Se)\gamma_w}{1 + e}$ and $\gamma = \dfrac{(G + Gw)\gamma_w}{1 + e}$, S = 0 and w = 0, Saturated Unit Weight (S = 1) Definition: Specific gravity of aggregate is the ratio of the mass of solids in a particular volume of sample to the mass of the same volume of water at the same temperature of the solids. This is because asphalt binder that is absorbed by the aggregate is not available to coat the aggregate particle surface and is therefore not available for bonding. An incorrect bulk specific gravity value will result in incorrectly calculated air voids, VMA, VFA and ultimately result in an incorrect mix design. Define and explain the differences among particle density, bulk density, and specific gravity. Geoengineer.org uses third party cookies to improve our website and your experience when using it. Therefore, thespecific gravity of soil particleis0.5. Table.1: Observations and Calculations for Specific Gravity of Soil The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. Dry the material until it maintains a constant mass. Thus as soil density increases, soil porosity decreases. The formula for calculating bulk density: s b = m / V Where: s b = Bulk Density m = Mass of the Soil V = Volume of the Soil Let's solve an example; Find the bulk density when the mass of the soil is 24 and the volume of the soil is 6. Ww = Weight of water You can also try thedemoversion viahttps://www.nickzom.org/calculator. Creative Commons Attribution 4.0 International License. From the above table, we can say that the specific gravity of the soil sample is 2.68. Aggregate absorption is a useful quality because: It is generally desirable to avoid highly absorptive aggregate in HMA. V = Volume of the Soil. total volume = volume of soilds + volume of voids Some lightweight shales (not used in HMA production) can have specific gravities near 1.050, while other aggregate can have specific gravities above 3.000. $\gamma ' = \gamma_{sat} - \gamma_w$, $\gamma ' = \dfrac{(G + e)\gamma_w}{1 + e} - \gamma_w$, $\gamma ' = \dfrac{(G + e)\gamma_w - (1 + e)\gamma_w}{1 + e}$, $\gamma ' = \dfrac{G\gamma_w + e\gamma_w - \gamma_w - e\gamma_w}{1 + e}$, $\gamma ' = \dfrac{G\gamma_w - \gamma_w}{1 + e}$, Unit weight of water = 9.81 kN/m3 = 9810 N/m3 = 62.4 lb/ft3. Basic formula for density (note: m = W/g) This page titled 1.9: Bulk Density, Particle Density, and Porosity is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Mark W. Bowen via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request. A (relatively) undisturbed, cylindrical soil core is collected using a device like the one shown in Figure 8.1. Absorption should typically be below 2 percent. (d)min = dry unit weight of the soil at its loosest condition Measure soil bulk density and calculate pore volume relationships. Specific gravity can also indicate possible material contamination. Relation Between Degree of Saturation, Specific Gravity, Water Content, and Void Ratio The degree of saturation may be defined as the ratio of the volume of water in the soil mass to the volume of voids in the soil mass. Known values: total mass of the soil sample, Mt=30.2 g, dry mass of the soil sample, Ms=23.3 g. air mass Ma is negligible. Calculating the Volume of the Soil when the Bulk Density and the Mass of the Soil is Given. The reference density of water at 4 o C (39 o F) is used as the reference as these are the conditions of maximum density. Lets solve an example; Soil is a three-phase materialthat consists of solid particles and voids which are filled with water and air. The volume expansion of the solid mineral is insignificant. This method, the simplest, calculates the volume based on height and diameter/width measurements. Q & A about Specific Gravity of Soil. Figure 9: Weighing the sample underwater. Therefore, the Specific Gravity GS is calculated as: A correction is utilized to adjust the results at a reference temperature T=20C: where K is the temperature correction factor. Preparation of Soil Sample: A representative sample of soil of 12 kg mass is taken if the maximum size of the soil particle is less than 75 mm. Want to create or adapt books like this? Grain size analysis is a typical laboratory test conducted in the soil mechanics field. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Your email address will not be published. "Good engineers don't need to remember every formula; they just need to know where they can find them. The bulk mass density of soil is defined as the ratio of total mass to total volume. Ans: Because at 4C the unit weight of water is 1. The following description is a brief summary of the test. It is not a complete procedure and should not be used to perform the test. Describe the relationship between 1) bulk density and porosity and 2) particle density and porosity. The specimens may have been molded in the laboratory or cut or cored form compacted pavements. e = current void ratio of the soil in-situ The relationship between the the void ratio e, and the porosity n is given by: Derivation is as follows Remove the aggregate from the water and dry it until it maintains a constant mass. Soil deposits consist of the soil particles and the void space between the particles. m = Mass of the Soil = 45. The formula for calculating specific gravity of soil particle: Gs= Specific Gravity of Soil Particle It is denoted by G. The wet soil in the box weighed 450 g. The dry soil weighed 375 g. Now calculate the bulk density. g = 9.81 m/s2 GS is a significant parameter of soil mechanics since it can be associated with the soils mineral composition and weathering. Typical values for bulk specific gravity range from 2.200 to 2.500 depending upon the bulk specific gravity of the aggregate, the asphalt binder content, and the amount of compaction. The soil sample is dried in an oven at a temperature of 105C to 110C. To derive the Specific Gravity of a soil, the following equipment is needed: The Specific Gravity is computed as the ratio of the weight in air of a given volume of soil particles at a stated temperature to the weight in air of an equal volume of distilled water at the same temperature. In this video we discuss in detail about the difference among apparent , bulk & effective specific gravity of aggregate. The equipment for this experiment is shown in Fig. Aggregate specific gravity is needed to determine weight-to-volume relationships and to calculate various volume-related quantities such as voids in mineral aggregate (VMA), and voids filled by asphalt (VFA). Now you have to learn some relations between these terms to solve any problem. The formulas for calculating bulk density and particle density follow: Bulk density, b = mass of oven dry soil total soil volume Bulk density, b = mass of oven dry soil total soil volume Particle density, p = mass of oven dry soil volume of soil solids Particle density, p = mass of oven dry soil volume of soil solids Figure 8.1. Effective unit weight is the weight of solids in a submerged soil per unit volume. Apple (Paid)https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8 Now you're ready to calculate density. For more accurate results it is recommended to conduct tests 3 times on the same soil sample. This indicates that all the water has left the sample. Total weight, $W = W_w + W_s$, Void ratio, $e = \dfrac{V_v}{V_s}$, Note: $0 \lt e \lt \infty$, Porosity, $n = \dfrac{V_v}{V}$, Note: $0 \lt n \lt 1$, Relationship between e and n, $n = \dfrac{e}{1 + e}$ and $e = \dfrac{n}{1 - n}$, Water content or moisture content, $w = \dfrac{W_w}{W_s} \times 100\%$, Note: $0 \lt w \lt \infty$, Degree of saturation, $S = \dfrac{V_w}{V_v}$, Note: $0 \le S \le 1$, Relationship between G, w, S, and e, $Gw = Se$, Moist unit weight or bulk unit weight, $\gamma_m = \dfrac{W}{V} = \dfrac{(G + Se)\gamma_w}{1 + e} = \dfrac{G( 1 + w)\gamma_w}{1 + e}$, Dry unit weight, $\gamma_d = \dfrac{W_s}{V} = \dfrac{G\gamma_w}{1 + e}$, Saturated unit weight, $\gamma_{sat} = \dfrac{(G + e)\gamma_w}{1 + e}$, Submerged or buoyant unit weight, $\gamma_b = \gamma_{sat} - \gamma_w = \dfrac{(G - 1)\gamma_w}{1 + e}$, Critical hydraulic gradient, $i_{cr} = \dfrac{\gamma_b}{\gamma_w} = \dfrac{G - 1}{1 + e}$, Relative Density, $D_r = \dfrac{e_{max} - e}{e_{max} - e_{min}} = \dfrac{\dfrac{1}{(\gamma_d)_{min}} - \dfrac{1}{\gamma_d}}{\dfrac{1}{(\gamma_d)_{min}} - \dfrac{1}{(\gamma_d)_{max}}}$, Atterberg Limits Once, you have obtained the calculator encyclopedia app, proceed to theCalculator Map,then click onAgriculturalunderEngineering. Void ratio is the ratio of volume of voids to the volume of solids. A = mass of oven-dry sample in air (g) These two density measurements provide an important insight into the physical nature of a given soil. To compute for specific gravity of soil particle, two essential parameters are needed and these parameters areDensity of water (w)andDensity of soil (s). Learn more about how Pressbooks supports open publishing practices. Use the thermometer to derive the temperature of the water. Let, = Weight of soil solid in a given soil mass. Laboratory specific gravity and absorption tests are run on two coarse aggregate sizes, which have to be blended. If the aggregate is not oven-dry to start, the existing water in the aggregate pore structrure may be able to penetrate further into the pores (AASHTO, 2000c. w s sws w w s s w s s M M . Either type of error will have a cascading effect on volumetric parameters in other tests that require specific gravity as an input and Superpave mix design. Therefore, by definition, water at a temperature of 73.4F (23C) has a specific gravity of 1. G = Specific gravity of solid particles, Bulk Unit Weight / Moist Unit Weight Where SG = specific gravity, = density of the material (kg/m 3 ), W = density of water ( kg/m 3 ). It is represented as 'Gm'. g = 32.2 ft/sec2. Submerge sample in 77F (25C) water for 4 minutes and record the submerged mass . If more than 2 percent water by volume is absorbed by the sample then this method is not appropriate. 1993 AASHTO Flexible Pavement Structural Design, 1993 AASHTO Rigid Pavement Structural Design, Climate Change Impacts on Pavements and Resilience, E-Construction in Practice: A Peer Exchange with WSDOT and TxDOT. However, if the maximum size of the soil particle is 75 mm, 45 kg of the sample should be used for the test. Requirements: (Note: Specific gravity of any element is unit less parameter). The determination of SSD conditions can be difficult. Density refers to a mass per unit volume. Any water that escapes from the sample during weighing is considered part of the saturated specimen. s = Density of Soil = 156. Effective Unit Weight, ' Download Solution PDF. The standard bulk specific gravity test is: Specific gravity is a measure of a materials density (mass per unit volume) as compared to the density of water at 73.4F (23C). The voids, or pore space, are important for air and water movement and storage. Also called buoyant density or buoyant unit weight (b).