VIP members get additional benefits.Lost your password? Cement, Sand, Coarse aggregate, and water with a suitable proportion of water.. All of these components are mixed according to batching or Concrete grade table, Maybe M10, M20, M25, M30, etc.
HenceVolume of all in aggregate = 1 – [{394.8/(3.15×1000)} + {197.4/(1 x 1000)}] = 0.6773 mMass of coarse aggregate = 0.6773 x 0.558 x 2.84 x 1000 = 1073.33 kg/mMass of fine aggregate = 0.6773 x 0.442 x 2.64 x 1000 = 790.3 kg/mFor casting trial -2, mass of ingredients required will be calculated for 4 no’s cube assuming 25% wastage.Volume of concrete required for 4 cubes = 4 x (0.15Mix is very cohesive, workable and had a true slump of about 60 mm.It virtually flowed during vibration but did not exhibit any segregation and bleeding.So , it has achieved desired workability by satisfying the requirement of 50-75 mm slump value .In case of trial mix 3 water cement ratio is varied by +10% keeping water content constant. This process is usually adopted for structures which requires higher grades of concrete such as M25 and above and large construction projects where quantity of concrete consumption is huge.. With corrected proportions three concrete cubes are cast and tested for 28 days compressive strength.A summary of all the trial mixes is given in the following Table.From Compressive Strength vs. c/w graph for target strength 31.6 MPa we get,= 1 – [{448.6/(3.15 x 1000)} + (197.4/1000)] = 0.660 mA reduction of 0.05 in w/c will entail and increase of coarse aggregate fraction by 0.01.Mass of coarse aggregate = 0.660 x 0.568 x 2.84 x 1000 = 1064.65 kg/mMass of fine aggregate = 0.660 x 0.432 x 2.64 x 1000 = 752.71 kg/mGopal Mishra is a Civil Engineer from NIT Calicut and has more than 10 years of experience in Civil Engineering and Construction. This process is usually adopted for structures which requires higher grades of concrete such as M25 and above and large construction projects where quantity of concrete consumption is huge..Benefits of concrete mix design is that it provides the right proportions of materials, thus making the concrete construction economical in achieving required strength of structural members. The concrete mix design involves various steps, calculations and laboratory testing to find right mix proportions. Higher the grade of concrete; higher will be the quality and vice versa. In this case standard deviation is taken from IS:456 against M 20 is 4.0.Maximum water-cement ratio for Mild exposure condition = 0.55Based on experience, adopt water-cement ratio as 0.5.Maximum water content = 186 Kg (for Nominal maximum size of aggregate — 20 mm)Estimated water content = 186+ (3/100) x 186 = 191.6 kg /mMinimum cement Content for mild exposure condition = 300 kg/mThis value is to be checked for durability requirement from IS: 456.In the present example against mild exposure and for the case of reinforced concrete the minimum cement content is 300 kg/mVolume of coarse aggregate per unit volume of total aggregate = 0.62Volume of coarse aggregate per unit volume of total aggregate = 0.62 x 90% = 0.558b) Volume of cement = (Mass of cement / Specific gravity of cement) x (1/100)c) Volume of water = (Mass of water / Specific gravity of water) x (1/1000)d) Volume of total aggregates = a – (b + c ) = 1 – (0.122 + 0.1916) = 0.6864 me) Mass of coarse aggregates = 0.6864 x 0.558 x 2.84 x 1000 = 1087.75 kg/mf) Mass of fine aggregates = 0.6864 x 0.442 x 2.64 x 1000 = 800.94 kg/mFor trial -1 casting of concrete in lab, to check its properties.For casting trial -1, mass of ingredients required will be calculated for 4 no’s cube assuming 25% wastage.Volume of concrete required for 4 cubes = 4 x (0.15Since the aggregate is saturated surface dry condition hence no correction is required.The mix proportion as calculated in Step 6 forms trial mix1. As, the quantity of concrete required for large constructions are huge, economy in quantity of materials such as cement makes the project construction economical.Concrete Mix design of M20, M25, M30 and higher grade of concrete can be calculated from example below. Sign Up to The Constructor to ask questions, answer people’s questions, write articles, and connect with other people. You will receive a link and will create a new password via email.Sorry, you do not have permission to ask a question, You must login to ask question. Concrete is a high compressive strength material for construction which makes a strong bond with Tor Steel.All of these components are mixed according to batching or Concrete grade table, Maybe M10, M20, M25, M30, etc.