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llc AL TFORNIA BEARING RATIO TEST Date: QV \4 Experiment No, AIM: To determine the Ca; lo . alifomia Bearing Ratio (CBR) of the given soil specimen. APPARATUS: a) Loading machine: Thi< ; his is a Compression machine, which can operate at a constant rate of 1.25 mm i . Per minute. A metal Penetration piston or plunger of diameter ° mm is attached to the loading machine. b) Cylindri ; ) Cyhndrical mould: Mould of 150 mm diameter and 175 mm height provided with a lar of collar of about SO mm length and a detachable base. A spacer disc of 148 mm diameter and 47.7 mm thickness is used to obtain a specimen of exactly 127.3 mm height. c) Compaction Rammer d) Annular weight: In order to simulate the effect of the overlying pavement weight, annular weights each of 2.5 kg weight and 147 mm diameter are placed on the top of the specimen, at the time of testing the sample, as surcharge. IMPORTANCE: The CBR is a measure of resistance of a material to penetration of standard plunger under controlled density and moisture conditions. The test procedure should be strictly adhered if high degree of reproducibility is desired. The CBR test may be conducted in re-moulded or undisturbed specimens in the laboratory. Many methods exist today, which utilize mainly CBR test values for designing pavement thickness requirement. PROCEDURE: i i tion. The preparation of i i s compacted by dynamic compac 1. Remoulded soil specimen ! d mming is more commonly adopted and is soil specimens by ynamic compaction or ra bout 4.5 kg material is d f material is retained on 2! eplacing it by an equal weight of material passing 20 mm r ried and sieved in 20 mm sieve. If a explained below. 4! 0 mm sieve, allowance for larger jon 0} noteworthy proportion terials is made by tained on 4.75 mv soil are determ" size mai sieve. The optimum moisture content and maximum m . sieve and re’ dry density of ned by adopting either IS light compaction (Proctor Scanned by CamScanner 
