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

Porosity, n Wash the aggregate retained on the No. s) = Ws/Vs; 12. What is the typical range of bulk density values for mineral soils? $\rho = \dfrac{m}{V}$. A sand sample weighing approximately 150 ml is added in the flask and its mass is determined now W 2. Upon completion of this laboratory exercise students should be able to directly measure bulk density and particle density using the graduated cylinder method for coarse textured, non-aggregated soil samples. High values can indicate non-durable aggregate. The screenshot below displays the page or activity to enter your values, to get the answer for the bulk density according to the respective parameters which is the Mass of the soil (m)andVolume of the soil (V). (March 2001). The most common method (and the one described in the Test Description section), calculates the specimen volume by subtracting the mass of the specimen in water (Figure 2) from the mass of a SSD specimen. Also called bulk unit weight (), and moist unit weight (m). Given: m = 36 g v = 3 mL = 1 g/mL Calculation: Density of the object = = = 12 g/mL Now, we know the density of both the elements that is the object and water. Aggregate absorption is a useful quality because: It is generally desirable to avoid highly absorptive aggregate in HMA. Lets solve an example; Finally, specific gravity differences can be used to indicate a possible material change. G= Specific gravity of soils. Describe several examples of soil management practices that increase or decrease soil bulk density. This results in less total pore volume. To get the answer and workings of the specific gravity of soil particle using the Nickzom Calculator The Calculator Encyclopedia. A cubic metre of it might weigh 1600 kg. Several important physical properties have been discussed in other labs: texture, structure, color, and consistency. G = specific gravity of soil solids When a gamma ray source of primary energy in the Compton range is placed near a material, and an energy selective gamma ray detector is used for gamma ray counting, the scattered and unscattered gamma rays with energies in the Compton range can be counted exclusively. NTP - Normal Temperature and Pressure - defined as 20 o C (293.15 K, 68 o F) and 1 atm ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 30 in Hg, 760 torr); Molecular weights can be used to calculate Specific Gravity if the densities of the gas and the air are evaluated at the same pressure and temperature. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Your email address will not be published. Examples of suitable units have been shown below. Fill around 2/3 of the flask with distilled water. Liquids and gases are mostly water and air, respectively. The bulk specific gravity test measures a HMA sample's weight under three different conditions (Figure 1): Dry (no water in sample). This lab is performed to determine the specific gravity of soil by using a pycnometer. G = Specific gravity of solid particles, Bulk Unit Weight / Moist Unit Weight Saturated surface dry (SSD, water fills the HMA air voids). This sample size is based on nominal maximum aggregate size (NMAS). Answer (1 of 3): What is the relationship between bulk density and specific gravity? UNIT WEIGHT OF SOIL SOLIDS (? Liquids and gases are mostly water and air, respectively. sb= Bulk Density Posted by Dinesh on 21-07-2021T12:27. Some lightweight shales (not used in HMA production) can have absorptions approaching 30 percent, while other aggregate types can have near zero absorption. The shrinkage limit of the specimen will be (adopt = 1.0 gm/cc) This question was previously asked in. You may have been told that 2.204 lb is equal to 1 kilogram or that 1 lb equals 0.454 kg, but what this really means is that a force of 2.204 lb results from that object's mass times the local value of gravity in some units or another. Aggregate specific gravity is used in a number of applications including Superpave mix design, deleterious particle indentification and separation, and material property change identification. Apple (Paid)https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8 Required fields are marked *. Specific gravity Specific gravity is defined as the ratio of the weight of a given volume of soil solids at a given temperature to the weight of an equal volume of distilled water at that temperature, both weights being taken in air. 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). Calculate the moisture content of the samples: Calculate the dry weight of the soil in each cylinder and record the data. m = Mass of the Soil 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. 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. Based on the temperature of the water that was recorded in the last step, the density of the distilled water w is derived through specific tables (i.e.,w=998.23 kg/m3 atT=20C). Repeat this process in ten mL intervals until you reach the 50 mL mark. Troxler Electronic Laboratories, Inc. Research Triangle Park, NC. Units of density are typically expressed in g cm3 or Mg m-3. The specimens may have been molded in the laboratory or cut or cored form compacted pavements. The volume of the box can be determined by multiplying the height of the box times its width and its depth. Measuring Bulk Specific Gravity of Compacted Specimens Using The Troxler Model 3660 CoreReader. Calculating the Density of Water when the Specific Gravity of Soil Particle and the Density of Soil is Given. The difference between Gsa, Gse and Gsb is the volume of aggregate used in the calculations. Specific Gravity of Solids The specific gravity of soil particles (G) is defined as the ratio of the mass of a given volume of solids to the mass of an equal volume of water at 4 C. G = ? Lets solve an example; It is not a complete procedure and should not be used to perform the test. S = Weight of Dry Piece Soaked in Fluid. Clean and dry the inside (above the water level) and the outer part of the flask and weigh it (, Use the funnel to carefully place the soil into the flask and weigh it (. Therefore, highly absorptive aggregates (often specified as over 5 percent absorption) require more asphalt binder to develop the same film thickness as less absorptive aggregates making the resulting HMA more expensive. D = Density of Fluid. Any water that escapes from the sample during weighing is considered part of the saturated specimen. This implies that; w = Density of Water = 22 Q.1: Define the Specific Gravity. It is represented as 'Gm'. Define and explain the differences among particle density, bulk density, and specific gravity. The total pore space consists of the voids between sand, silt, and clay particles and voids between soil aggregates. The equipment for this experiment is shown in Fig. 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. If the sample is actually still wet on the surface then the mass of the SSD sample will be higher than it ought to be, which will cause a lower calculated bulk specific gravity. Students will also learn to calculate soil porosity. $\gamma = \dfrac{W}{V}$, $\gamma = \dfrac{\gamma_w V_w + \gamma_s V_s}{V_v + V_s}$, $\gamma = \dfrac{\gamma_w V_w + G \gamma_w V_s}{V_v + V_s}$, $\gamma = \dfrac{V_w + G V_s}{V_v + V_s}\gamma_w$, $\gamma = \dfrac{S V_v + G V_s}{V_v + V_s}\gamma_w$, $\gamma = \dfrac{S (V_v/V_s) + G (V_s/V_s)}{(V_v/V_s) + (V_s/V_s)}\gamma_w$, Moist unit weight in terms of dry density and moisture content The relative density is written in the following formulas: where: = Weight of soil solid in a given soil mass. 3. Absorption can be used as an indicator of aggregate durability as well as the volume of asphalt binder it is likely to absorb. Lets solve an example; In materials science, bulk density, also called apparent density or volumetric density, is a property of powders, granules, and other "divided" solids, especially used in reference to mineral components (soil, gravel), chemical substances, (pharmaceutical) ingredients, foodstuff, or any other masses of corpuscular or particulate matter ().. The volume includes both solids and pores. The sample will be held in the longer cylinder; the two 1.5 cm rings are spacers, which help ensure an undisturbed soil sample. emin = void ratio of the soil at its densest conditiond = current dry unit weight of soil in-situ In this case, use AASHTO T 275, Bulk Specific Gravity of Compacted Bituminous Mixtures Using Paraffin-Coated Specimens or AASHTO TP 69, Bulk Specific Gravity and Density of Compacted Asphalt Mixtures Using Automatic Vacuum Sealing Method. Calculate bulk density, particle density, and porosity using the following formulas. The container overflow needs to work properly to compensate for the water displaced by the sample. Density refers to a mass per unit volume. Basic formula for density (note: m = W/g) The calculation should then be: SG = Ps/Pw Find The Soil Testing Equipment You Need At Certified MTP When dealing with soil samples, the average particle density of soil is 2.66 g/ (cm^3). Now, Click onSoil Mechanics and FoundationunderAgricultural, Now, Click on Specific Gravity of Soil Particle underSoil Mechanics and Foundation. The complete procedure can be found in: The mass of a coarse aggregate sample is determine in SSD, oven-dry and submerged states. Make sure to use cloth and not paper towels. 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. If the unit weight of soil is 50% saturated, then its bulk unit weight will be _____ If the unit weight of soil is 50% saturated, then its bulk unit weight will be ______ Nickzom Calculator The Calculator Encyclopedia is capable of calculating the bulk density. What are the sizes of macropores and micropores? The substance might be 20 mm gravel. Want to create or adapt books like this? 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. Q.2: Why unit weight of water is taken at 4C. Certainly, the accuracy of all measurements is important. However, direct volume measurements are difficult, therefore weight measurements are usually made and then converted to a volume based on material specific gravities. How to Calculate and Solve for Air Content of the Soil | Soil Mechanics and Foundation, How to Calculate and Solve for Water Content | Soil Mechanics and Foundation, How to Calculate and Solve for Inter-atomic Spacing | Braggs Law, How to Calculate and Solve for Conversion of Volume Fraction to Mass Fraction | Phase Transformation, How to Calculate and Solve for Net Force between Two Atoms | Crystal Structures, How to Calculate and Solve for Planar Density | Crystal Structures, How to Calculate and Solve for Linear Density | Crystal Structures, https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator, https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator, https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8. w = Density of Water. h=depth of heave soil prism/unit length pile. It is an important parameter in soil mechanics for the calculation of the weight-volume relationship. Bulk density of a soil refers to the mass of a volume of dry soil. Laboratory specific gravity and absorption tests are run on two coarse aggregate sizes, which have to be blended. 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? It is an important parameter in soil mechanics for the calculation of the weight-volume relationship. w = Water content or moisture content $V_v = V_w + V_a$, total weight = weight of solids + weight of water The relationship between specific gravity of solid particles G, water content or moisture content w, degree of saturation S, and void ratio e, is given by the following: The formula above can be derived as follows: First, you need to obtain the app. = Weight of water. Lets solve an example; e = current void ratio of the soil in-situ It may be necessary to wipe the larger particles separately. An incorrect specific gravity value will result in incorrect calculated volumes and ultimately result in an incorrect mix design. Bulk specific gravity is involved in most key mix design calculations including air voids, VMA and, indirectly, VFA. Now, enter the values appropriately and accordingly for the parameters as required by the Density of water (w) is 22 andDensity of soil (s) is 11. Weigh and record weight (A). w = water content or moisture content, Density of water and gravitational constantw = 1000 kg/m3w = 1 g/ccw = 62.4 lb/ft3 5.9.15 BULK SPECIFIC GRAVITY AND UNIT WEIGHT OF COMPACTED HOT MIX ASPHALT (HMA) (Kansas Test Method KT-15) 1. 3-1. Bulk Specific Gravity Calculator. 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 Particle density is similar to the specific gravity of a solid and is not impacted by land use. 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). Therefore, texture and structure govern the amount of soil pore space. Web page on the Troxler web site. Soil is composed of solids, liquids, and gases. i av = N d at middle of heave soil prism /unit length pile. With the dimensions of the cylinder and the weight of oven-dry soil inside the cylinder, we can calculate the bulk density. Dry Mass Density With proper calibration, the gamma ray count is directly converted to the density or bulk specific gravity of the material (Troxler, 2001[1]). This method has shown promise in both accuracy and precision. 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. 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.] V = Volume of the Soil = 6. Relative Density = Mass of the Aggregate / Mass of equal volume of water. \ (\mathrm {Gm}=\frac {\text { Weight of soil of given soil }} {\text { weight of standard fluid of same volume }}\) Measuring flask method Measuring flask is of 250 ml (or 500 ml) capacity . This can be done with a water-filled container on top of a scale or with a basket suspended in water under a scale (Figure 2). This indicates that all the water has left the sample. Return 50 mL sample in graduated cylinder to 50 mL beaker. The following formulas are taken from unit weights of soil: $\rho_{sat} = \dfrac{(G + e)\rho_w}{1 + e}$, Where The Soil Specific Gravity is defined as the ratio of the weight of a given volume of the material to the weight of an equal volume of distilled water. ( w) The mean density of water (default is 1,000 kg/m 3) Now, Click on Soil Mechanics and Foundation underAgricultural, Now, Click on Bulk Density underSoil Mechanics and Foundation. Determine the weight of dry soil in the sample. Shake the container to release any entrapped air before weighing. Laboratory samples are typically dry at the beginning of the test; however, field samples will typically be damp. Correct and accurate bulk specific gravity determinations are vital to proper mix design. If particle density remains constant, as bulk density increases porosity decreases. As you can see from the screenshot above,Nickzom Calculator The Calculator Encyclopedia solves for the bulk density and presents the formula, workings and steps too. Gently stir soil/water mixture to remove any air bubbles. Apple (Paid)https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8 Android (Free)https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator Typically, aggregate used in HMA production will have an absorption between just above zero and 5 percent. Weight-Volume Relationship from the Phase Diagram of Soil. Calculating the Mass of the Soil when the Bulk Density and the Volume of the Soil is Given. Organic matter affects the solids portion of the soil but also influences porosity indirectly through its effect on structure. Ws = Weight of solid particles Low bulk density soils are easily compacted and may settle considerably to the detriment of roads, sidewalks, and building foundations. Dry unit weight is the weight of dry soil per unit volume. The specific gravity of solid particles is defined as the ratio of the mass of a given volume of solids to the mass of an equal volume of water at 4 C. $W = W_s + W_w$. V = Volume of the Soil. Saturated Unit Weight, sat "Good engineers don't need to remember every formula; they just need to know where they can find them. If a soil is compacted, the soil solids are packed into a smaller volume, and the particles get packed closer together. 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. To find the formula for density, divide the formula of unit weight by gravitational constant g (acceleration due to gravity). V = Total volume of the given soil mass. These methods, based on Archimedes Principle, calculate specimen volume by weighing the specimen (1) in a water bath and (2) out of the water bath. The flow of liquids and through soil is essential for the existence of plants and other soil organisms. These two (water and air) are called voids which occupy between soil particles. Absorption should typically be below 2 percent. Fill the flask with distilled water up to the graduation mark. The general values for specific gravity for different soils are given in Table -1. Determine water content within a soil sample as a percentage, by drying the soil in the oven at 105oC for 24 hours. Engineering Civil Engineering A sand sample has a bulk density of 20kN/m and a degree of saturation of 70%. 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. One method for determining bulk density is the core method. An introduction to density, specific weight and specific gravity. Specific gravities can vary widely depending upon aggregate type. 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. 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 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. From $\gamma = \dfrac{(G + Se)\gamma_w}{1 + e}$, S = 100%, Buoyant Unit Weight or Effective Unit Weight Find the density of soil when the specific gravity of soil particle is 12 and the density of water is 9. m = Mass of the Soil Therefore, by definition, water at 73.4F (23C) has a specific gravity of 1. To compute for specific gravity of soil particle, two essential parameters are needed and these parameters areDensity of water (w)andDensity of soil (s). 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 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. Moisture content, usually expressed in terms of percentage, is the ratio of the weight of water to the weight of solids. Relative density is an index that quantifies the state of compactness between the loosest and densest possible state of coarse-grained soils. Cool the aggregate to a comfortable handling temperature. w = Density of Water = 9. The density is given by 850/0.5 = 1700 kg/m^3. Simply divide the mass of the sample by the volume of the water displaced. 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). 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. Considerable preparation time may be necessary if contamination must be removed from the bottom of the sample. Bulk Specific Gravity Formula. Remember, the volume of the water displaced is equal to the volume of the. How to Calculate and Solve for Degree of Saturation | Soil Mechanics and Foundation, How to Calculate and Solve for Unit Weight | Soil Mechanics and Foundation, How to Calculate and Solve for Inter-atomic Spacing | Braggs Law, How to Calculate and Solve for Conversion of Volume Fraction to Mass Fraction | Phase Transformation, How to Calculate and Solve for Net Force between Two Atoms | Crystal Structures, How to Calculate and Solve for Planar Density | Crystal Structures, How to Calculate and Solve for Linear Density | Crystal Structures, https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator, https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator, https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8. Mathematically , G = Ms / Mw = s / w = s / w Where, s = Density of Solid w = Density of Water s = Unit Weight of Solid w = Unit Weight 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). 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) Equation for calculate bulk specific gravity is, G b = (W * D) / (W - I) Where, G b > = Bulk Specific Gravity. Weigh and record graduated cylinder plus compact soil weight (C). Remove the sampler from the soil by pushing against the handle until the vertical shaft of the handle is parallel to the soil surface. Weight-Volume Relationship from the Phase Diagram of Soil = Weight of water present in the given soil mass. 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. It is the Specific Gravity of Soil. 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. V = Volume of the Soil Sample sizes range from 2000 g for a 0.5 inch (12.5 mm) NMAS to 5000 g for a 1.5 inch (37.5 mm) NMAS. INSTRUCTIONS: Choose units and enter the following: () The mean density of the object or liquid. 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. Void Ratio, e The difference between Gsa and Gsb is the volume of aggregate used in the calculations. Thus as soil density increases, soil porosity decreases. 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. V = Volume of the Soil = 4. Porosity is the ratio of volume of voids to the total volume of soil. 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 Soils are composed of a combination of solids (soil particles), liquids (soil water), and gases (soil atmosphere). Bulk density is a commonly measured soil property by agriculturalists and engineers. w= Density of Water V = volume of soil Dry the material until it maintains a constant mass. $\gamma = \dfrac{(G + Se)\gamma_w}{1 + e}$, $\gamma = \dfrac{(G + Gw)\gamma_w}{1 + e}$, $\gamma_{sat} = \dfrac{(G + e)\gamma_w}{1 + e}$, $\gamma ' = \dfrac{(G - 1)\gamma_w}{1 + e}$, $D_r = \dfrac{e_{max} - e}{e_{max} - e_{min}}$, MATHalino - Engineering Mathematics Copyright 2023. $V = V_s + V_v$, volume of voids = volume of water + volume of air The above values have been provided with both imperial and metric units.