There are so many materials that your students can use to construct bridges. I started my classes off with a video from Mystery Science about the Golden Gate Bridge. Mystery Science is a new website that is amazing!!!! You can sign up for a free trial for one year and then they require a paid subscription. Our school has purchased it for our teachers. The videos are engaging, interactive and give science lessons a real purpose/connection. The lessons are aligned to the NGSS standards and come with lessons and resources. The website is for K-5. I teach fifth grade and used the lesson for third and found it was appropriate and aligned to my engineering standards.
My students used paper to construct bridges and tested them for strength using pennies. It was a great starting point to observe failure points and introduce vocabulary. The recording sheet is available on their website.
Here is another video you can use with your students.
Here is a great literature connection available on Amazon.