Basic Civil Engineering Questions and Answers – Bulking of SandThe increase in moisture of sand increases the volume of sand. The reason is that moisture causes film of water around sand particles which results in the increase of volume of sand. For a moisture content percentage of 5 to cortisone injection shoulder pain after there will bulking sand an increase in volume up to 20 to 40 percent depending upon sand. If the sand is more bulking sand there will be more increase in bulking sand. This is known as bulking of sand. When the moisture content of sand is increased by adding more water, the sand particles pack near each other and the amount of bulking of sand is decreased.
Bulking of Sand Test - Experiment Procedure and Importance - Civilology
The volume of a given quality of Sand varies according to its moisture content. Therefore, the measurement of sand by volume should take into account its moisture content periodically in a day after every 04 hrs. The Bulking increases with fineness of sand, because of large surface area contributed by fine particles for the same volume contribution.
River sand is dredged from river bed making it wet. Water present in sand can influence fresh and hardened properties of concrete and mortar. Workability increases as there is an increase in the water content.
Excess water content leads to Plastic shrinkage cracks. Bulkage of wet sand is determined by filling a graduated cylinder up to a certain mark with the wet sand and the volume is noted, Say V1. The cylinder is then filled with water to submerge the sand sample completely and shaken. The volume of sand is again noted, Say V2.
The quantity of sand shall be one full box and an extra depth of 6 cm of sand in the same box has to be added. At site, the same graph can Indicative Bulkage Curve be used to determine moisture content indirectly from the corresponding bulkage value, after bulkage is determined by standard method the quality of sand sample is more or less same as used in laboratory for making a calibration curve.
Hence the quantity of wet sand has to be adjusted to Kg because of site condition to get the required dry sand quantity of Kg designed quantity assuming dry sand. Hence the quantity of water has to be reduced to Liter water reduced by 25 liter from designed amount , as wet sand of kg will have the same amount of water.
Useful for the Engineers and the Contractors, particularly for site Engineers , to avoid the disputes between the contractors and the engineers on that how much bulkage should be added at site in the concrete or cement mortar.
Very nice post, interesting. Useful for Site engineers and bring value for quality control. We need consider allowence for bulkage of sand in case of batching of concrete by weigh batch mix? We need not consider bulkage as we are batching material by weight and not by volume, in the case of concrete production by weigh batcher. Here we should reduces water content in proportion to moisture in sand and extra sand is to be added, equal to water content reduced.