Choose the correct answer from the followings   Use ACI method to design a concrete mix which is required to obtain f'c28 = 34.5MPa and a slump of 75mm . The fineness modulus of the aggregate is 3.0 , the bulk density of coarse aggregate is 1600 kg/m² and the maximum size is 25. Both the specific gravity of fine and coarse aggregate are 2.68. neglect the absorption and total moisture content .   1- The W/C ratio is *       a-0.74       b-0.48       c-0.57       d-0.61     2- The cement content is *       420 kg/m3       240 kg/m3       204 kg/m3       402 kg/m3     3- The carse aggregate content is *       1140 kg/m3       1004 kg/m3       1040 kg/m3       1400 kg/m3     4- The fine aggregate content is *       807 kg/m3       780 kg/m3       708 kg/m3       870 kg/m3

Concrete is required for several structural members of a residential house. Due to the present moisture, it is expected that the concrete shall be non-aerated (Non AE) with a 28 day compressive strength of 3.000 psi for slabs and 4,000 psi for beams and columns. Due to extra moisture present in the site, the slump to be used shall be the minimum allowed by the ACI mix. Using a 3/4 inch max aggregate size, compute for the weight of cement, water coarse aggregate, and fine aggregate. Aggregate details: Cement: Type 1. Specific Gravity = 3.15 Coarse Aggregate: Bulk Specific gravity (SSD) = 2.65; absorption capacity = 4%. Dry-rodded unit weight= 100 lb/ft: surface moisture 1.2% Fine Aggregate: Bulk Specific Gravity (SSD) = 2.60: Absorption capacity = 1.5%: Fireness modulus = 2.70: Surface moisture= 496 Structural members dimmensions: Columns: 8 pes 300mm x 300mm x 3100mm (Length x Width x Height) Beam: 9 pcs. 300mm x 500mm x 4000mm (Length x Width x Height) Slab: 12000mm x 4000mm x 400mm…

Working on major construction project that requires considerable amounts of concrete to be used,you are asked to design a concrete mix following the BRE methodology. The concrete mixspecifications are:o Characteristic compressive strength of 50 N/mm 2 at 7 days.o Failure rate of 2%o Previous control data yielded a standard deviation of 5 N/mm 2o CEM-I 52.5o Air-entraining is not requiredo Required slump 120 mmo Coarse aggregate: Crushed maximum size 10mmo Fine aggregate: Uncrushed with 45% passing 600 μm sieveo Relative density of aggregates: 2.7o Coarse aggregate has 4% moistureo Fine aggregate is dry and has 1.2% absorption.o Volume of the required trial mix: 0.120 m3 Create the mix design and state what actions and recommenations you would do if trial produced a result with a mean compressive strength of 64 MPa at 7 days and the slump was 80mm.