required % of chemical and mineral admixture ,follow steps as per blogThank you for the above mix design, Can you please elaborate which table “column/row’ to be picked for inputs ,for designing M40 grade concrete.”, While all other factors remain the same. The concrete mix ratio refers to the proportion of the components in the concrete. {{#message}}{{{message}}}{{/message}}{{^message}}It appears your submission was successful. The concrete mix ratio is usually represented by the quality of various materials per cubic meter of concrete, or amount proportion of various materials. S = Assumed standard deviation in N/mm2 = 5 (as per table -1 of IS 10262- 2009) = 30 + 1.65 x 5.0 = 38.25 N/mm2. Therefore Mix Ratio of M30 Grade concrete by weight is Cement : F.A : C.A : Water = 1 :1.63 : 2.8 : 0.45.
Design mix has to be done as per exact site requirements.Yes, the all the values (cement, FA, CA and water) can be halved to achieve 0.5 cum of concretecan you share please the target combined grading of aggreagtes (20mm : 10mm : 6mm) …Your query is not clear. Clause 4.2 suggests an increase of 3% of water content for every extra 25mm slump from 50mm slumpWeight of cement for mix design of M30 grade concrete can be calculated from the water-cement ratio and the water content.Coarse aggregate ratios for different Zones of Fine aggregates are given in Table 3 of IS10262.
Thanks for A2A.
These are ratios are valid for 0.5 Water-cement ratio. Grades of concrete are: Mix design M30 Grade designed as per IS 10262:2009 & IS 456:2000; Mix design M35 Grade designed as per IS 10262:2009 & IS 456:2000 ; Comments. Step-1 : Determining the Target Strength for Mix Proportioning.
Read this post to understand the difference between Nominal Mix and Design Mix. The mix proportions shall be reworked for the actual water content and checked for durability requirements.Two more trials having variation of +/- 10% of water cement ratio shall be carried out and a graph between three water-cement ratios and their corresponding strength shall be plotted to work out the mix proportions for the given target strength for field trials. Hence Target strength (FStandard deviation (S) value for the M30 grade concrete is given in table 8 of IS456.After 28 days of curing, concrete should have more than 38.25 N/mmThe maximum water-cement ratio to design M30 grade concrete can be found from Table 5-IS456 given above.You can reduce the water-cement ratio for M30 grade concrete based on your requirements, but remember that Water-cement ratio directly affects the strength of the concrete.Maximum water content for 20mm aggregate to get up to 50mm slump is given in Table 2 of IS10262.
Estimated water content for 100 Slump = 186+(6/100) X 186 = 197 litreCement Content = Water content / “w-c ratio” = (197/0.50) = 394 kgsMinimum cement Content for moderate exposure condition = 300 kg/m3From Table 3 of IS 10262- 2009, Volume of coarse aggregate corresponding to 20 mm size and fine aggregate (Zone I) = 0.60Note 1: In the present case water-cement ratio is 0.5.So there will be no change in coarse agreegate volume i.e. 0.60 .Note 2: Incase the coarse aggregate is not angular one, then also volume of coarse aggregate may be required to be increased suitably based on experience.The mix calculations per unit volume of concrete shall be as follows:Note-1: Aggregates should be used in saturated surface dry condition. Hence we need to subtract 0.01 from the C.A ratio.This section deals with calculating the weight of fine aggregate and coarse aggregate from the aggregate ratio, cement and water. (a) Characteristic compressive strength required in the field at 28 days grade designation — M 30(b) Type of Cement : OPC 53 Grade confirming to IS 12269(e) Type of exposure the structure will be subjected to (as defined in IS: 456) — ModerateThe following materials are to be tested in the laboratory and results are to be ascertained for the design mix(a) Cement Used : OPC 53 Grade Confirming to IS 12269(c) Chemical admixture : Super plasticizer confirming to IS 9103Aggregate are assumed to be in saturated surface dry condition usually while preparing design mix.Fine aggregates : Confirming to Zone I of Table 4 IS – 383 F’ck = Target average compressive strength at 28 daysFck = Characteristic compressive strength at 28 daysS = Assumed standard deviation in N/mm2 = 5 (as per table -1 of IS 10262- 2009)Note : Under control conditions if Target average compressive strength is achieved then at field the probability of getting compressive strength of 30 MPa is very highFrom Table 5 of IS 456, Maximum water-cement ratio = 0.50Note : Do not start with w/c ratio above 0.50,even though the other desired results like Strength, workability could be achieved.Maximum water content for 20 mm aggregate = 186 Kg (for 25 to 50 slump)We are targeting a slump of 100mm, we need to increase water content by 3% for every 25mm above 50 mm i.e.
Concrete mix design is a procedure of selecting the suitable ingredients of concrete and their relative proportions with an objective to prepare concrete of certain minimum strength, desired workability and durability as economically (value engineered) as possible.As we decide to go for a concrete mix design, collect the following data before hand as few design stipulation are freezed on the basis of these data.Purely governed on the local conditions, were the concrete need to be appliedThe exposure condition limits the minimum cement content, maximum water – cement ratio and minimum grade of concrete.As per exposure condition, you have the above data for working the first trial and arriving its mix proportion.If you are getting desired result at a lower cement content, you need to put extra as mentioned by IS 456. The surface water and percenetage water abosorption shall be determined according to IS 2386.Correction in water content due to absorption or moist aggregatesThe slump shall be measured and the water content and shall be adjusted for achieving the required slump based on trial, if required.