Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Aluminous cement is used for what type of chemical deposit?

I think Option B is the correct answer.

Clay is more porous than sand. The Permeability of sand is higher.

The reason for that is clay particles are platy and smaller in size which allows it to have more void space as a total, however, the individual spaces are smaller in size than the void spaces created by the sand particles. Other factors affecting the analysis is the tendency of clay to swell which allows it to have even higher volume than the sand. The Degree of compaction and initial void ratio and initial moisture content are other factors. In controlled testing where equal volumes of clay and sand (clay is suppressed with surcharge weights to avoid swelling), the porosity of clay would be higher than that of sand. The permeability of sand is obviously higher than clay which is not debatable.

@Chintu is right. Porosity is water holding capacity. So clay is more porous than sand.

I think porosity is the number of pores. Not the holding capacity.

Yes, porosity (No of the pore) is more in clay but it's not continuous.

Porosity and permeability are directly proportional and its fact that porocity of clay is more then that of sand but in case of clay, particle are electrically charged and due to charged partical waters are hold by clay.

Porosity refers to the open spaces within a material. Porosity values are based on the ratio of pore volume to total volume and it is more in clayey soil.

Porosity of gravel: 25-40%.

Porosity of sand: 25-50%.

Porosity of clay: 40-70%.

Permeability refers to the ability of a material to allow for the passage of a fluid due to interconnected voids. Permeability of gravel>sand>clay.