Concrete is required for a column that will be Severe Exposure to freezing and thawing. The cross section of the column is 300 × 300 mm. The smallest spacing between reinforcing steel is 40 mm. The specified compressive strength of concrete at 28 days is 40 MPa with a slump of 25 to 50 mm. The properties of materials are as follows: (a) Cement used is type I Portland cement with a specific gravity of 3.10. (b) The available coarse aggregate has a maximum size of 23 mm, a dry-rodded unit weight of 1800 kg/m3, a bulk specific gravity (SSD) of 2.68, absorption capacity of 0.65%, and moisture content (SSD) of 0.27%. (c) The fine aggregate has a bulk specific gravity (SSD) of 2.75, absorption capacity of 1.5%, a moisture content (SSD) of 2.5%, and a fineness modulus of 2.7 ,The aggregates conform to the ASTM C33-84 requirements for grading.

The properties of hardened concrete also affected by curing process. Analyze any possible defect occurred in concrete without curing

Correctly define which of the stress versus strain graphs represent the comparison of 8 ksi and 4 ksi concrete for the chart below (say left or right). Qualitatively compare the w/c ratio, elastic modulus, and brittleness. 0.000 0.003 0.000 0.003 Sean, e Sane Feure 2 Strss vesus Srain curves Feure 2. Stress vasus rain curve