Building URI with the http client API

Building URI with the http client API

I have to build a URI address with dynamic query strings and looking for a
comfortable way to build them via code.
I browsed the System.Net.Http assembly but doesn't found a class or method
for this case. Does this API doesn't provide this? My searches here at
StackOverflow uses the HttpUtility class from the System.Web, but I don't
want to reference any ASP.Net components in my class library.
I need a URI like this : http://www.myBase.com/get?a=1&b=c.
Thanks in advance for helping!