Answer to Question #305316 in Civil and Environmental Engineering for James

Question

Design the concrete mix according to the following conditions:

Design Environment

 Building frame

 Required design strength = 27.6 MPa

 Minimum dimension = 150 mm

 Minimum space between rebar = 40 mm

 Minimum cover over rebar = 40 mm

 Statistical data indicate a standard deviation of compressive strength of 2.1 MPa is expected

(more than 30 samples).

 Only air entrainer is allowed.

Available Materials

 Air entrainer: Manufacture specification 6.3 ml/1% air/100 kg cement.

 Coarse aggregate: 19 mm nominal maximum size, river gravel (rounded)

 Bulk oven-dry specific gravity = 2.55, Absorption = 0.3%

 Oven-dry rodded density = 1761 kg/m3

 Moisture content = 2.5%

 Fine aggregate: Natural sand

 Bulk oven-dry specific gravity = 2.659, Absorption = 0.5%

 Moisture content = 2%

 Fineness modulus = 2.47

Answer 1

Answer is given below