Design the concrete mix according to the following conditions: Design Environment • Concrete slab o Subjected to freeze and thaw. o Required design strength = 21 MPa o Slab thickness = 300 mm. o Statistical data indicate a standard deviation of compressive strength of 1.7 MPa is expected (more than 30 samples). • Only air entrainer is allowed. • Available Materials: o Air entrainer: ▪ Manufacture specification is 9.5 mL/1% air/100 kg cement. o Coarse aggregate: ▪ 25 mm nominal maximum size ▪ Crushed stone ▪ Bulk oven-dry specific gravity = 2.573 ▪ Absorption = 2.8 ▪ Oven-dry rodded density = 1922 kg/m3 ▪ Moisture content = 1 o Fine aggregate: ▪ Natural sand ▪ Bulk oven-dry specific gravity = 2.540 ▪ Absorption = 3.4 ▪ Moisture content = 4.5 ▪ Fineness modulus = 2.60 o Cement: ▪ Type I Cement ▪ Specific gravity = 3.15 e) The corrected amount of mixing water (kg).
Design the concrete mix according to the following conditions:
Design Environment
• Concrete slab
o Subjected to freeze and thaw.
o Required design strength = 21 MPa
o Slab thickness = 300 mm.
o Statistical data indicate a standard deviation of compressive strength
of 1.7 MPa is expected (more than 30 samples).
• Only air entrainer is allowed.
• Available Materials:
o Air entrainer:
▪ Manufacture specification is 9.5 mL/1% air/100 kg cement.
o Coarse aggregate:
▪ 25 mm nominal maximum size
▪ Crushed stone
▪ Bulk oven-dry specific gravity = 2.573
▪ Absorption = 2.8
▪ Oven-dry rodded density = 1922 kg/m3
▪ Moisture content = 1
o Fine aggregate:
▪ Natural sand
▪ Bulk oven-dry specific gravity = 2.540
▪ Absorption = 3.4
▪ Moisture content = 4.5
▪ Fineness modulus = 2.60
o Cement:
▪ Type I Cement
▪ Specific gravity = 3.15
e) The corrected amount of mixing water (kg).
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