The bulking of sand refers to an increase in the volume of dry sand when it becomes saturated with water. This increase in volume is primarily due to the fact that water molecules create a film around the sand particles, causing them to separate and take up more space. The amount of bulking can vary depending on factors such as the type of sand and its particle size. It’s an important consideration in construction and engineering when measuring and transporting sand, as you need to account for this volume increase when determining the quantity of sand required for a project.
Bulking of sand
Sand is an important construction material of natural origin,mixed with cement and lime ,today sands are used effluent and widely for construction as mortars, plasters, and concrete.
Bulking of sand is defined as the increase in the volume of sand due to formation of a thin film of atmospheric moisture around sand particles. This layer generates a force between particles to move aside to each other.
The term bulking is used for rock particles that range in grain size between, in composition they are predominantly an oxide of silica SiO2
Mineralogically, they consist mostly of broken grains of mineral quartz SiO2 produced as a result of the breakdown of sandstones and similar rocks.
The quality of sand is determined concerning it’s clay content, contamination with organic impurities and it’s salt encrustations.
Generally the sand is occurs a form of formation, size of particles and composition, like as type of sand according to formation is pit sand, river sand, sea sand and according to size of particles it is fine sand, coarse sand, gravely sand and also according to composition it is associated as a form of clean sand, silty sand and clayey sand.
This is widely significant in construction of civil engineering structures which is greatly used in mortar, concrete and also adopted for greatly significant in all purposes and behave importance in geotech and gain behavioral properties in civil engineering construction.
What is bulking of sand?
Regarding this, “what is bulking of sand?”, the increase in volume of a given mass of fine aggregates or sand due by the presence of water is called bulking of sand, this result is a drawback and gives misleading behaviour of sand.
The bulking of sand create a film of water around the particles of sand that is existing the against forces which effect the particles of sand due to this result the particles to get a side from each other and thus the volume is increased.
The sand is gain a behaviour “bulking of sand” according to availability of the quantity of water in the sand and also the sizes of the particles which is effect the this manner, if 5 to 8 percentage of the increase in water in the sand can increase the volume of sand up to 20 to 40 percentage.
Bulking of sand is also depends on the sizes of particles, in the behaviour of finer the sand is more will be the increase in volume and in case of coarser sand is more will be the increase in volume but relatively more than finer sand.
Bulking of sand definition
Bulking of sand is defined as the behaviour of increase in volume of sand due to availability of water content which is formed a thin film of water around the particles of sand cause them to get side from each other that resulting increase in volume of sand is called the bulking of sand.
Especially bulking of sand totaly depends on the moisture content, it increase with the increase in water content and also due to this result in increased in volume of sand.
Finer sand particles create a behaviour as extreme bulking, further addition of water cause film around particles break and volume of sand get reduced.
Bulking of sand means
Bulking of sand means, generally we understand in simplified terms, it is simply the behaviour of looseness of soil without compacting, means the water content reduces the pores in sand and compacts the sand.
We shall try to understand the in simple words through examples – in construction of concrete structures, if requirements of sand in cubic metre unit that is 1 M3 of sand in concrete, we can necessary to know the approximate sand bulkage of value ,this is depend on the given sample bulkage value if the bulkage of 25 percent then we require to take 25 percent more sand or in other words we could said that the 1.25 times of the sand is required while volume batching to get 1 M3 of sand of concrete.
Bulking of sand caused due to
Bulking of sand caused due to as follows-:
1. Water forms a film over fine aggregates particles
2. Force of surface tension exerts and pushes them apart resulting in formation of huge space in between the particles, ultimately exhibition of increase the volume.
3. More water brakes the film and bulking damages.
4. Percentage of moisture content in the sand
5. Grain size of the sand particles.
Bulking of sand occurs due to
Bulking of sand occurs due to especially in two factors, percentage of moisture content in the sand and gain size of the sand particles, this behaviour of sand is increases with increase in moisture content upto certain level after that it decreases. Basically bulking of sand is observed in natural sand.
Bulking of sand occurs, we shall understand the occuring of bulking behaviour of sand in simple terms, as know that during the mixing of concrete in construction of concrete structures or mortar the sand in wet conditions is added to the cement or lime, resulting mortar will be associated with a lesser amount of sand than the required amount, so sand has to be adopted as a behaviour of bulking of sand after determining the rate of bulking of the sand to be used in concrete and mortar making for all the designs mix proportions of sand is proper and effective with cement or lime.
Bulking of sand test
Bulking of sand test is determined the bulkage value of sand correspondence to presence of moisture content which is able to sustain the behaviour and properties of concrete in construction of concrete, mortar and plaster etc. its bulkage value is measured by the measuring scale, this is associated with the apparatus a measuring cylinder, steel ruler steel rod.
Bulking of sand test procedure
Bulking of sand procedure observed with containing apparatus a cylinder with250 ml, steel ruler, steel rod and measuring apparatus.this procedure is followed as following steps-:
1. A measuring cylinder is filled with the sample upto 200 ml. It’s volume is V1=200 ml
2. Carefully sand is to be transferred to a container.
3. Refilled the measuring cylinder with 100 ml water.
4. Sample sand reffiled and stirring the water while adding sand into it by a steel rod.
5. Then after sometime that the sand settle a level below the 200 ml mark denoted as volume V2
6. Bulking of sand determined for the this sample
Bulking of sand formula= 200-V2/V2 x 100
This procedure is repeated twice and average value of three observation will be the percentage of bulking of sand .
Bulking of sand graph
How to calculate of bulking of sand
Bulking of sand formula = measured height of sand- height of sand with water/ height of sand with water x100
We will understand the calculation of bulking of sand with examples in simple test of bulking of sand-:
● pour the sample of sand in a measuring glass cylinder of 250 ml capacity.
● Shaking the sand upto this sample is reached to 200ml mark.
● now, fill the water in cylinder and stirring the level of sand reached below the 200 ml mark, suppose this mark is 160 ml.
● Then calculate the percentage of bulking of sand
H = measuring glass cylinder capacity = 250 ml
H1= Height of sand and water in cylinder= 200 ml
H2= Height of sand in water after stirring the sand=160 ml
Bulking of sand formula:-
Bulking of sand %= (H1- H2/ H2) x 100
= ( 200 – 160)/ 169 x100
= 40/160 x100
= 25%
● This test procedure is resulting the bulking of sand 25% ,that means volume of sand is increased due to mixing of moisture content and stirring it’s.
● 4 % of moisture content in sample increased the 25 % volume of sand means that bulk value of sand is 25% .
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Basic points of bulking of sand
● In general the bulking of sand depends upon percentage of moisture content and particle size of fine aggregates.
● If design mix is proportionaly not provided the concrete will be under sanded, harsh, less durable and also play a important role to affecting the strength of the concrete in construction of structures.
● Percentage of moisture content= 2, then bulking by volume percentage= 15
● Percentage of moisture content= 3, then bulking by volume percentage= 20
● Percentage of moisture content= 4, then bulking by volume percentage= 25
● Percentage of moisture content= 5, then bulking by volume percentage= 30
● Generally bulking of sand observed with in a range of 20 to 40 percentage.
● This is mostly observed in natural sand.
● Bulking of sand reaches maximum between 4 to 6 percentage water content.
Bulking of sand is maximum if moisture content is about, we know that the bulking of sand occurs in the moisture content of 5 percentage, this is maximum at 4.6 percentage moisture content, and also bulking of sand is observed with the 5 to 8 percentage of the increase in moisture content in the sand can increase the volume of sand upto 20 to 40 percentage.
Bulking of sand occuring depends on the grading of sand, finer sand possess more bulking than the medium and coarser sand, thus bulking in the sand is high for fine sand and low for coarse sand.
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Bulking of sand permissible limit
Bulking of sand permissible limit is 20 to 40 percent which is change according to availability of moisture content round the particles, these are adopted beter in weight batching, the bulking of sand value is follows as -:
Percentage of moisture content= 2, then bulking by volume percentage= 15
● Percentage of moisture content= 3, then bulking by volume percentage= 20
● Percentage of moisture content= 4, then bulking by volume percentage= 25
● Percentage of moisture content= 5, then bulking by volume percentage= 30