Aggregate, which has been artificially heated, shall not normally be used if such aggregate is used then it should be mentioned in the report.ġ. Take about 500 grams of aggregate or weight the amount of aggregate for a sample as instructed by the teacher. Container – An airtight container large enough to take the sample. Tray – A shallow tray of an area not less than 325 cm square.Ħ. ![]() Cloth – Two dry soft absorbent cloths, each not less than 75 x 45 cm.ĥ. Glass vessel – A wide-mouth glass vessel of about 1.5 liters capacity, with a flat ground lip and a plane ground disc of plate glass to cover it, giving a virtual watertight fit.Ĥ. Oven – A well ventilated, thermostatically controlled oven in order to maintain the temperature of 100 degrees Celsius to 110 degrees Celsius.ģ. Balance – A balance or scale of capacity not less than 3 kg, readable and accurate to 0.5 gram and of such type as to permit the weighing the vessel containing the aggregate and water.Ģ. Softening Point of Bituminous MaterialsĪs per IS 2386 (Part III) – 1963, the apparatus to be used are as follows:ġ.Bitumen Penetration Test – Consistency Test.Determination of Normal Consistency of Cement.Fineness Modulus of a Sample of Fine Aggregate.Determination of Initial and Final Setting Time of Cement.Determination of Fineness of Cement by Sieving.Determination of Specific Gravity of Sand.The percentage of water absorbed by an aggregate when immersed in water is termed as absorption of aggregate. The water absorption is determined by measuring the decrease in mass of a saturated and surface-dry sample after oven drying for 24 hours. The absorption and porosity affect the bond between the aggregate and the cement paste, the resistance of concrete to freezing and thawing, stability and resistance to abrasion. Absorption of air-dried aggregates is, however, less than bone-dry aggregates. Thus, if the phenomenon of absorption is ignored in totally dry aggregates, both workability and effective water-cement ratio are reduced. If the aggregate is dry, it absorbs water, which takes part neither in chemical reaction nor in the lubrication of particles. The Apparent specific gravity of majority of natural aggregate lies between 2.6 and 2.7 The apparent average specific gravity of different rock groups are:īasalt: 2.80, Granite: 2.7, Lime Stone: 2.66 with a wide range of variation. If the specific gravity is above or below that normally assigned to a particular type of aggregate, it may indicate that the shape and grading of the aggregate have changed. It is seen that the higher the specific gravity of an aggregate, the harder and stronger it is likely to be. ![]() This specific gravity is required for the calculation of the yield of concrete or of the quantity of aggregate required for a given volume of concrete. The specific gravity most frequently required and easily determined, known as ‘gross apparent specific gravity’, is based on the saturated and surface-dry condition of the aggregate because the water absorbed in the pores of the aggregate does not take part in the chemical reaction of the cement and can, therefore, be considered as a part of the aggregate. The Apparent specific gravity is then the ratio of the mass of the aggregate dried in an oven at 100 degrees Celsius to 110 degrees Celsius for 24 hours to the mass of water occupying a volume equal to that of the solid including the impermeable pores. ![]() If the volume of the solid is deemed to include the impermeable pores, but not the capillary ones, the resulting specific gravity is called ‘Apparent specific gravity’. Generally, it is not required for civil engineering construction work. ![]() The absolute specific gravity refers to the volume of solid material excluding all pores, and therefore, is defined as the ratio of the mass of solids to the weight of an equal gas-free volume of water at a stated temperature. Since the aggregate generally contains voids, there are different types of specific gravities. The specific gravity of an aggregate is defined as the ratio of the mass of the solid of a given volume of sample to the mass of an equal volume of gas-free distilled water, both taken at the standard temperature i.e. Performance objectivesĪ) To determine the specific gravity, an apparent specific gravity of the aggregate.ī) To determine water absorption of the aggregate.Ĭ) List the limits in which specific gravity falls.Į) To follow the procedural steps with precautions.į) To fill up the observation table correctly. Determination of specific gravity and water absorption of aggregate having the size between 10 mm to 40 mm.
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