Can I request an answer to a question I already asked?
Here's how you'd do that.
In order to request an answer for your questions, or for any question for that matter, click on the "heart" button located right before the text of the question
Don't be confused about the fact that this button also serves as a "likes" counter for answered questions!
For unanswered questions, the heart button serves as a "request answer" button. For answered questions, it serves as a "like" button.
Now, for questions you posted, you can only click on the "request answer" button once. As you would imagine, allowing people to keep bumping their own questions would not qualify as a good idea.
However, other users can request answers to your question if they want. Here's an example of such a question
The question was originally asked by Gio, then answer requests were made by Trippy, Kevin B, and Kyx. Notice that this corresponds to the number of hearts shown next to the question, one for each request + one from the original question.