There are a few different ways that you can concentrate on building strength as well as building muscle. I am going to share with you my favorite workout that does both of those things (concentrating on biceps). Here is what you do:

First, you need to know what your max is as far as curling dumbbells goes. For this example, I will say that your max is 80 pounds. Now, at the gym, take 5 sets of dumbbells, and line them up one next to the other. The first set should be about 10 pounds,the second set should be about 20 pounds,the third set should be about 40 pounds,the fourth set should be about 60 pounds,and the fifth set should be your max (80 pounds in this example).

Warning: This workout will really push you to your limits

Starting at the first set, knock out 7 reps. When you finish the first set, take no more than 15 seconds rest, and move to the second set. Continue in this pattern until you get to your max. Once you complete your max set, work your way back down, except do only 5 reps of each. By the time you get back to the first set, you will feel like you are lifting 80 pounds, even on the 10 pound set!

What this routine does is push you as close as possible to muscle failure. You want to reach muscle failure on just about every workout! This helps break your muscles down, and forces your body to build them back up, thus making you stronger, while creating more muscle mass!