Porosity or void fraction is a measure of the void (i.e. “empty”) spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%.

On the whole, porosity is directly dependent on the initial water content, temperature, pressure, relative humidity, air velocity, electromagnetic radiation, food material size, composition, and initial microstructure and viscoelastic properties of the biomaterial, as shown in Fig. 4.1 (Saravacos 1967; Krokida et al.

The void ratio of a mixture is the ratio of the volume of voids to volume of solids. is porosity, VV is the volume of void-space (air and water), VS is the volume of solids, and VT is the total or bulk volume.

Four basic porosity types can be recognized in sandstones: (1) intergranular (primary), (2) microporosity, (3) dissolution (secondary), and (4) fracture (Figure 2). Intergranular porosity exists as space between detrital grains.

Soil type void ratio e Uniform sand, loose 0.85 Mixed-grain sand, dense 0.43 Soft glacial clay 1.20 Soft highly organic clay 3.00 Soft Bentonite 5.20 Page 6 Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay ➢ In nature, even though the individual void spaces are larger in coarse-grained soils, the …

Soil void ratio (e) is the ratio of the volume of voids to the volume of solids: e = (V_v) / (V_s) Where V_v is the volume of the voids (empty or filled with fluid), and V_s is the volume of solids.

Abstract. The minimum void ratio is an important parameter for evaluating soil properties. It is closely related to the compressive properties, permeability, and shear strength of soil, and it is affected by particle size distributions and particle shapes.

The minimum void ratio is an index widely used to indicate the contraction characteristics and the densest state of soils. The minimum void ratio obtained by the traditional test method has been utilized to represent the density of soils irrespective of their fines content despite the restriction (FC ≤ 5%).

The percentage of superficial area which is lost by holes, perforations, or cores.

In a process occurring at a constant water content, the product of the degree of saturation and the void ratio remains constant (Fig. 4). When freezing occurs in a closed system, without access to free water, the increase in volume induced by the water phase change leads the void ratio to increase and the …

Void ratio is the ratio of volume of voids to the total volume and thus cannot be negative if we follow the right approach.

Porosity (n) is volume of water and air present in total soil mass for example water+air present in voids of solids and extra water air present on top of soil which makes it easier for agriculturists to understand because of which they use the term porosity over void ratio like engineers.

Soils with a high PI tend to be clay, Those with a lower PI tend to be silt, and.

The plasticity index is expressed in percent of the dry weight of the soil sample. It shows the size of the range of the moisture contents at which the soil remains plastic. A high PI indicates an excess of clay or colloids in the soil. Its value is zero whenever the PL is greater or equal to the LL.

The Weighted Plasticity Index (WPI) is defined as the value of the plasticity index (PI) times the % passing the 425 micron sieve. The Contractor must provide the calculations to verify the WPI.

Fill material include: • Type A material – a superior quality material complying with the requirements of Table 204.041and used principally as capping, selected material, structural material and/or verge material.

Abstract and Figures. The commonly used Plasticity Index (PI) test disposes the material retained on the 425 micron sieve, thus is not representative of the whole sample. The weighted plasticity index (WPI) accounts for the portion used in the PI test and this is important for classification of residual soils.

The binding characteristics of these materials generally increase subgrade load-bearing capacity. Typically, lime is used with highly plastic soils (plasticity index greater than 10), cement is used with less plastic soils (plasticity index less than 10) and emulsified asphalt can be used with sandy soils.

The CBR test is performed by measuring the pressure required to penetrate a soil sample with a plunger of standard area. The measured pressure is then divided by the pressure required to achieve an equal penetration on a standard crushed rock material. The harder the surface, the higher the CBR value.