It is obtained by testing concrete cylinder specimen. However, empirical formulas can be used to convert cube strength to cylinder strength and vice-versa. As per Indian code definition “ The compressive strength of concrete is given in terms of the characteristic compressive strength of 150 mm size cubes tested at 28 days fck .
Compressive strength as a concrete property depends on several factors related to the quality of used materials, mix design and quality control during concrete production. Depending on the applied code, the test sample may be cylinder 15 cm x 30 cm is common or cube 15 cm x 15cm x 15 cm is the most common .
Compressive strength of concrete depends on many factors such as water-cement ratio, cement strength, quality of concrete material, quality control during production of concrete etc. Test for compressive strength is carried out either on cube or cylinder. Various standard codes recommends concrete cylinder or concrete cube as the standard ...
Compression testing machine of capacity 2000 kN is used for compression testing of cube and cylinder as casted of size 150x150x150 mm and 150x300 mm and capable of giving load at the rate of 140 kg/sq.cm/min. Testing of the concrete cubes and cylinders are tested under CTM at the age of 28 days. The wet specimens were placed in the machine between
Test for compressive strength is can be dobe by either on cube or cylinder. There is various standard codes recommends concrete cylinder or concrete cube as the standard specimen for the test. The American Society for Testing Materials of construction ASTM C39/C39M provides Standard Test Method for Compressive Strength of cube and Cylindrical ...
Compressive strength of Concrete Formula: The Compressive strength of specimen can be calculated by dividing maximum load carried by the specimen by cross-sectional area of the specimen cubes. The surface area of specimen: = 150 x 150 = 22500mm² = 225cm². Assume, The Max compression load is 450KN. 1KN = 1000N ; 450Kn = 450×100 = 450000N
Assume, the approx weight of one concrete cube = 8 kg Then the volume of concrete = 0.15 x 0.15 x 0.15 = 0.0033 cum; So for 1 cum = 8/0.0033 = 2400 kg/ cum Since the concrete weight itself has also been assumed for the structural calculations, if it exceeds the assumed value, then the load on the structure will likely increase.
Keywords: Concrete, Rate of loading, Correction Factor, Cube Test, Strength I. INTRODUCTION Compressive strength of concrete is determined by testing concrete cubes of size 150mm x 150 mm x 150 mm. CTM, either electronic or manually operated are used for this purpose. The strength of concrete is tested on site using manually operated CTM.