List the three of the most important structural engineering properties of hardened concrete. For each of the 3 properties, outline the major factors affecting each of these mechanical properties. (12 marks)

A concrete sample with a theoretical thickness of 37.5 mm. The characteristic compressive strength at 28 days is 50 MPa. The final basic drying shrinkage is 800×10-6.

(i) Calculate the dry shrinkage at 1000 days if we assume the sample is in interior environment. (8 marks)

(iii) Calculate the total design shrinkage strain at 1000 days. (4 marks)

(ii) Calculate the autogenous shrinkage at 1000 days. (8 marks)

Discuss which hardened property the most common concrete test measures and why it is important. (10 marks)

(iii) Why an aspect ratio of 2 is adopted here to conduct the compressive strength test? (2 marks)

(ii) In compressive strength test, the sample failed at a load of 468 kN and displacement of 0.58 mm. Calculate the failure strength and failure strain. (4 marks)

A cylinder concrete sample with a diameter of 150mm and the height is 300mm.

(i) In splitting tensile test, the sample failed at a load of 300 kN and displacement of 0.3 mm.

Calculate the tensile strength of concrete. (4 marks)

Describe two types of time-dependent deformation that occur in concrete and their mechanism. (8 marks)

The design shrinkage in AS3600 standard is the sum of ...