reinforced/prestress concrete?

Garfield is right.

the advantage of using prestressed concrete is to reduce the crack width, especially water containing structure has a stringent crack width requirement = 0.15mm

However, there are lots difficulties associated with the construction aspect if using prestressed concrete

1: complicated construction joint details
2: complicated jacking / dead anchor details with waterproofing requirement.
3: crack free prestressed structure is in theory only. cracks are unpredicted even under laboratory condition. They are highly sensitive to the construction details & sequencing. You can't hardly find that there are lots of bridge with severe cracks on the deck / column.

Personally speaking, I won't use prestress for water tank design. It is too risky.

如果你上internet search下，你會發現外國有pre stressed concrete water tank (http://www.durastortank.com/CASESTUDIES/WATERSTORAGETREATMENT/tabid/1520/Default.aspx)，香港有無我就唔知。


我只係bridge engineer，未設計過prestressed concrete water tank。不過以同一厚度嘅牆，我想信用prestressed concrete係可以設計到water tank表面嘅crack細好多。呢一點對防止concrete中鋼筋生銹係十分重要。

Presstressed concrete有什麼disadvantage for designing water tank->我係好明個問題！


係設計上，prestressed concrete比 reinforced concrete 複雜。不過係電腦化年代，設計pre stressed concrete所花時間巳經比以前少好多，其實問題不大。而係施工方面，prestressed concrete construction係要請specialist contractor幫手，所以建築成本高d。

I'm sorry because I'm afraid that I'm unable to help you.