Compressive Strength of Hydraulic Cement

COMPRESSIVE STRENGTH OF HYDRAULIC CEMENT(IS:4031-Part 6-1988) Published by Suryakanta on May 4, 2013 | 6 Responses Overview Compressive strength of cement is determined by compressive strength test on mor tar cubes compacted by means of a standard vibration machine. Standard sand (IS: 650) is used for the preparation of cement mortar. The specimen is in the form o f cubes 70.6mm*70.6mm*70.6mm. Apparatus Measuring Instruments NAME CAPACITY / RANGE / SIZE ACCURACY / LEAST COUNT Cube mould 70.6*70.6*70.6 mm3(IS:10080) Vibration machine Should be as per IS:10080 Balance 1000 g 1 g Measuring cylinder 200 ml 1 ml Other Apparatus Enamel tray, Trowel, Poking rod Cement Mould Cement Mould Environmental Conditions Temperature 27 ± 20 C Humidity 65 ± 5 % Test Procedure Take 200 g of cement and 600 g of standard sand and mix them dry thoroughly. Add cement consistency 2 of water (where P is % of water required for preparing paste of standard consistency) to the dry mix of cement and sand and mix thorou ghly for a minimum of 3 minutes and maximum of 4 minutes to obtain a mix of unif orm colour. If even in 4 minutes uniform colour of the mix is not obtained rejec t the mix and mix fresh quantities of cement, sand and water to obtain a mix of uniform colour. Place the thoroughly cleaned and oiled (on interior face) mould on the vibrating machine and hold it in position by clamps provided on the machine for the purpo se. Fill the mould with entire quantity of mortar using a suitable hopper attached t o the top of the mould for facility of filling and vibrate it for 2 minutes at a specified speed of 12000±400 per minute to achieve full compaction. Remove the mould from the machine and keep it in a place with temp of 27±20C and r elative humidity of 90% for 24 hours. At the end of 24 hrs remove the cube from the mould and immediately submerge in fresh clean water. The cube be taken out of the water only at the time of testin g. Prepare at least 6 cubes in the manner explained above. Place the test cube on the platform of a compressive testing machine without any packing between the cube and the plates of the testing machine. Apply the load steadily and uniformly, starting from zero at a rate of 35 N/mm2/ minute. Calculation Cement compressive 1 Where, P=Maximum load applied to the cube. (N)

A=Cross sectional area (Calculated from the mean dimensions) (mm2) Compressive strength is reported to the nearest 0.5 N/mm2. Specimens that are manifestly faulty, or that give strengths differing by more t han 10% from the average value of all the test specimen should not be considered . Test three cubes for compressive strength for each period of curing. Precautions The mould should be oiled before use The weighing should be done accurately The temperature and humidity must be accurately controlled Increase the load gradually during testing. The cubes should be tested immediately after taking out of water and not allowed to dry until they fail under testing. The gauging time should be strictly observed. The cubes should be tested on their sides and not on their faces. Standard Specifications CEMENT TYPE COMPRESSIVE STRENGTH (Mpa) 1 Day 3 Days 7 Days 28 Days OPC(33) 16 22 OPC(43) 23 33 OPC(53) 27 27 SRC 10 16 PPC 16 22 RHPC 16 27 PSC 16 22 High alumina 30 35 Super sulphated 15 Low heat 10 Masonry 2.5 IRS-T-40 Technical Discussions

33 43 53 33 33 33 22 16 5.0 37.5

30 35

Strength tests are not made on a neat cement paste because of difficulties of mo ulding and testing with a consequent large variability of test results. Compressive strength is influenced by the cement type, or more precisely, the co mpound composition and fineness of cement. It should be assumed that two types of cement meeting the same minimum requireme nts will produce the same strength of mortar or concrete without modification of mix proportions. Related Posts HOW TO CHECK QUALITY OF CEMENT ON SITE? HOW TO CHECK QUALITY OF CEMENT ON SITE? HOW TO DO SAMPLING OF CEMENT FROM BAGS? HOW TO DO SAMPLING OF CEMENT FROM BAGS? SOUNDNESS OF CEMENT BY AUTOCLAVE METHOD (IS:4031-Part 3-1988) SOUNDNESS OF CEMENT BY AUTOCLAVE METHOD (IS:4031-Part 3-1988) SOUNDNESS OF CEMENT BY LE-CHATELIERS METHOD (IS:4031-Part 3-1988) SOUNDNESS OF CEMENT BY LE-CHATELIERS METHOD (IS:4031-Part 3-1988) HOW TO DETERMINE STANDARD CONSISTENCY OF CEMENT PASTE? HOW TO DETERMINE STANDARD CONSISTENCY OF CEMENT PASTE? INITIAL & FINAL SETTING TIME (IS:4031-Part 5-1988) INITIAL & FINAL SETTING TIME (IS:4031-Part 5-1988) Share this:

EmailPrintMore Posted in Tests On Cement Tagged Cement Test Article written by Suryakanta Geotechnical-Material Engineer. You can connect me on Google +. To know more abo ut me just visit AboutMe 6 Responses Wilfred Wilfred May 24, 2013 at 7:28 pm | Permalink | Reply That s an interesting method that you use to conduct compression testing on Portla nd cement. However, we use a method similar to ASTM C109 method when conducting compression testing on Portland cement with 50mm Mortar Cubes. RAGHUNANDAN PRAKASH NAGAR RAGHUNANDAN PRAKASH NAGAR November 10, 2014 at 10:03 pm | Permalink | Reply Explain formula (P/4+3) the water requirement for compressive strength (P/4+3) w ater (where P is % of water required for preparing paste of standard consistency ) Suryakanta Suryakanta November 11, 2014 at 9:15 am | Permalink | Reply Amount of dry material = 200+600 = 800g Suppose water required for standard consistency (P) = 24 ml Then [(P/4)+3] = [(24/4)+3] = 6+3 = 9 Calculate 9% of dry material i.e. 9% of 800 g = (9*800)/100 = 72 g So add 72ml of water in the dry mix of sand and cement. Thank you Have a Great Day surya surya December 14, 2014 at 12:47 pm | Permalink | Reply Kindlly give me details of three cube mould holder of 70.7*70.7*70.7 and its vib rating table details on urgent basis sangay chedup