Bulking Of Sand 3x296n

The phenomena of bul ing of sand is discussed in the previous chapter. The im portant facts in connection with the bul ing of sand are as follows: (1) When moisture content is increased by adding more water, the sand particles pac near each other and the amount of bul ing of sand is decreased. Thus the dr y sand and the sand completely flooded with water have practically the same volu me. (2) The coarse aggregate is little affected by the moisture content. (3) One of the reasons of adopting proportioning by weight is the bul ing of san d as proportioning by weight avoids the difficulty due to the bul ing of sand. (4) The bul ing of sand should be ta en into when volumetric proportioni ng of the aggregates is adopted. Otherwise, less quantity of concrete per bag of cement will be produced, which naturally will increase the cost of concrete. Al so, there will be less quantity of line aggregate in the concrete mix which may ma e the concrete difficult to place. AIM To study the behaviour of sand grains under varying percentage of moisture conte nt . APPARATUES. 250 ml measuring cylinder ,weighing balance etc . PROCEDURE (i) Ta e 500gm (W1) of the aggregate. (ii) Keep the sample in an oven in a tray at a temperature of 100°C-110° C for 24 ± 0. 5 hours . (iii) Cool the sand in an air tight container and weight it (W2) Water content of the sample = (W1-W2)x 100/W1 (iv) Ta e out about 250gm of sand and pour it into a pan. (v) Add 2% (by weight) of water and mix well. (vi) Pour the sand sample into a 250 ml measuring cylinder and consolidate by sh a ing. (vii) Level the surface and read the volume in ml (Yi). (viii) Ta e out the whole quantity of sand and continue the experiment by adding 2% water more each time and note the corresponding volume of sand (Y2,Y3…..) unti l the dump sand volume starts decreasing. (ix) Beyond this point, add 4% more water each time until the sample become full y saturated. (x) To the standard sample in the measuring cylinder, add about 50 ml water ore and stir the sample well. (xi) Note down the surface level of inundated sand (Y ml).

CALCULATIONS Bul ing =(Y1-Y)x100/Y GRAPH A graph drawn with % water content along X-mas and % bul ing along Y- axis. From the graph, pic out maximum % of bul ing occurred, % of water content at ma ximum bul ing , % of water content When bul ing is zero & % of bul ing for the i nitial water content (W) of the sample. RESULTS % of bul ing occurred = % of water content at maximum bul ing= % of water content when bul ing is zero= % of bul ing for the initial water content (W) of the sample = FIELD TEST FOR BULKING OF FINE AGGREGATES AIM To determine necessary adjustment for the bul ing of fine aggregate, in the fiel

d. APPARATUES 250 ml measuring cylinder PROCEDURE (I) Pour the dump sand in to a 250 ml measuring cylinder up to the 200 ml mar . (II) Fill the cylinder with water and stir well (sufficient water should be pour ed to submerge the sand compleately and it can be see that the sand surface is n ow below its original level) (III) Ta e the reading at the sand surface (Y ml) CALCULATIONS % of bul ing { (200/Y)- 1] x100 Report the percentage bul ing of the sand to the nearest whole number. RESULT Percentage bul ing of field sample= Related Tags: construction contracts sand bul ing testing, pdf presentation of bul ing of sand , factors affecting sand bul ing, sand bul ing test, testprocedure sand bul ing, note bul ing of sand, bul ing of sand limits, range and value ofbul ing of sand , bul ing of sand test procedure, concrete bul ing factor, as per is what is for mula for bul ing of sand, field moisture content test for fine aggregate by is s td,

Fine Sand Fine sand should consist of natural sand or crushed stone sand. It should be har d, durable, clean and be free from organic matter etc.Fine Sand should not conta in any appreciable amount of clay balls and harmful impurities such as al alis, salts, coal, decayed vegetation etc. The silt contents should not exceed 4%. Classification of Sand Classification of sand is given below. 1. Fine sand = 0.075 to O.425 MM 2. Medium sand = 0.425 to 2 MM 3. Coarse Sand = 2.0 to 4.75 MM Various Types of Sand There are following three types of sand. 1. Pit Sand 2. River Sand 3. Sea Sand Pit Sand (Coarse Sand or Badarpur) Pit sand is obtained by forming pits into soil from ‘Quarries’. It consists of sharp angular grains which are free from salts. It is coarse sand which is usually us ed in concreting and has reddish yellow color normally. River Sand This sand is obtained from ban s or beds of rivers. River sand is fine and consi sts of fine rounded grains. The color of river sand is almost white and Grayish. River sand is usually available in clean condition and is used for plastering. Sea Sand This sand is obtained from sea shores. It has fine rounded grains and light brow n color. Sea sand contains salts which attract moisture from atmosphere. Such ab sorption causes dampness and disintegration of wor . Sea sand also retards setti ng action of cement. Due to these reasons, sea sand is generally avoided for eng ineering purposes. It is used only as a local material for nonstructural purpose s. Sand for Construction Wor s

Different construction wor s require different standards of sand for constructio n. • Bric Wor s: finest modulus of fine sand should be 1.2 to 1.5 and silt contents should not be more than 4%. • Plastering Wor s: finest modulus of fine sand should not be less than 1.5 and si lt contents should not be more than 4%. • Concreting Wor s: coarse sand should be used with finest modulus 2.5 to 3.5 and silt contents should not be more than 4%. NOTE • If the above quality of sand is not available due to any reason, the blending o f sand should be done by adding more coarse sand to achieve the required finest modulus. • Washed sand should be used at site for getting more strength in construction wo r . Bul ing of Sand Due to moisture in each particle of sand, sand gets a coating of water due to su rface tension which eeps the particles apart. This causes an increment in volum e of sand nown as Bul ing.