Use the British method to design a GP concrete mix that is required to have a...

 

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Use the British method to design a GP concrete mix that is required to have a specified mean strength of 35 MPa at 28 days. The presence of reinforcement requires a slump of 75 mm and a maximum size of aggregate of 10 mm. The aggregates are of normal weight, uncrushed and gradings conform to the appropriate standard with a fineness modulus of 3.0; the specific gravity of combined aggregate (SSD) is 2.65. All tables and figures are the same as the week 2 mix design worksheet. (A) Refer to Table 1, Table 2 and Figure 1 below, and estimate the water/cement ratio (5 marks) and free water content. (2 marks) (B) Refer to Figure 2 and Figure 3 below and calculate the wet density of fully compacted concrete (3 marks), weight of fine and coarse aggregate content (15 marks). Please upload the scanned pdf of your solution. The calculations should be clearly shown and the necessary diagrams should be included. Table 1: Approximate compressive strengths (MPa) of concrete mixes made with a free-water/cement ratio of 0.5 Type of Cem en t Type of coarse aggregate Type GP or Type SR Type HE Compressive strength (MPa) 90 80 70 60 40 30 20 10 0 0.3 Uncrushed Crushed Uncrushed Crushed 3 17 22 24 31 Compressive Strengths (MPa) Age (days) 0.8 7 24 31 N 36 39 28 38 45 47 52 0.4 0.5 0.6 0.7 Free water / cement ratio Figure 1 Relationship between compressive strength and free water/ cement ratio 91 45 54 52 60 Use the British method to design a GP concrete mix that is required to have a specified mean strength of 35 MPa at 28 days. The presence of reinforcement requires a slump of 75 mm and a maximum size of aggregate of 10 mm. The aggregates are of normal weight, uncrushed and gradings conform to the appropriate standard with a fineness modulus of 3.0; the specific gravity of combined aggregate (SSD) is 2.65. All tables and figures are the same as the week 2 mix design worksheet. (A) Refer to Table 1, Table 2 and Figure 1 below, and estimate the water/cement ratio (5 marks) and free water content. (2 marks) (B) Refer to Figure 2 and Figure 3 below and calculate the wet density of fully compacted concrete (3 marks), weight of fine and coarse aggregate content (15 marks). Please upload the scanned pdf of your solution. The calculations should be clearly shown and the necessary diagrams should be included. Table 1: Approximate compressive strengths (MPa) of concrete mixes made with a free-water/cement ratio of 0.5 Type of Cem en t Type of coarse aggregate Type GP or Type SR Type HE Compressive strength (MPa) 90 80 70 60 40 30 20 10 0 0.3 Uncrushed Crushed Uncrushed Crushed 3 17 22 24 31 Compressive Strengths (MPa) Age (days) 0.8 7 24 31 N 36 39 28 38 45 47 52 0.4 0.5 0.6 0.7 Free water / cement ratio Figure 1 Relationship between compressive strength and free water/ cement ratio 91 45 54 52 60