As a concrete technologist of a reputed ready‐mix concrete supplier, you have been requested to produce a report documenting your selection of a concrete mix and concrete specification for a major bridge project on a freeway in Sydney. The construction phase requires 24 circular reinforced concrete bridge piers of about 2.0 m diameter and heights varying between 4 to 7 m to be erected above the foundation level. The reinforced concrete pier heads, which will carry the 2‐lane traffic in one direction, will need to span 7 m in width. The concrete mix and concrete specification selected for this project needs to meet the following three (3) requirements:  Minimum slump of 100 mm  Maximum internal temperature, monitored by thermocouples, limited to 60°C  Characteristic strength of 40 MPa Question 1  Design two (2) suitable concrete mixes to meet the three (3) requirements (i. e., minimum slump, maximum internal temperature and characteristic strength). For one concrete mix (i. e., mix 1), the binder must comprise fly ash and cement and for the other concrete mix (i. e., mix 2) the binder must comprise ground granulated blast furnace slag and cement. For each concrete mix (i .e, mixes 1 and 2), give the proportions of concrete making materials required to produce the concrete (per m3). Question 2 Explain the differences that exist in the heat of hydration behaviour between the two (2) concrete mixes designed in Question 1. From these two (2) concrete mixes, select a single concrete mix to use in the project. Justify your reasons for making this selection. Question 3 An option of using self‐compacting concrete (SCC) for the project has been proposed. Describe how the concrete mix selected in Question 2 can be modified to meet the requirements of a SCC mix. Design a suitable SCC mix to meet the three (3) requirements (i. e., minimum slump, maximum internal temperature and characteristic strength). For this SCC mix, give the proportions of concrete making materials required to produce the concrete (per m3). Question 4 If the freeway is to be constructed in an environment running parallel to the seacoast, and within 50 m of the seacoast, describe the concrete mix design considerations that need to be taken into account to ensure durability against chloride‐induced corrosion is met. Page 3 of 3 Question 5 Prepare a suitable concrete specification that meets the three (3) requirements (i. e., minimum slump, maximum internal temperature and characteristic strength) and the durability requirements of Question 4 (i. e., resistance to chloride‐induced corrosion). When preparing this concrete specification, ensure that the following requirements are also addressed: Type and amount of binder to use to prevent other long‐term durability issues such as sulphate attack and alkali‐silica reaction Type of aggregates to use to prevent alkali‐silica reaction Type of superplasticiser or any other chemical admixtures to use Quality control tests to be carried out on concrete delivered to the construction site Method of placing, time of formwork removal and any subsequent curing needed