You can do measurement activities. Bring in tape measures and have them measure different aspects of the room. You can have them discover perimeter by finding out how far it is to go all the way around your room.
You can build pulleys and ramps and talk about how they help make jobs easier.
The students can draw plans of their own buildings and label them.
You can set up a construction center. The students can use low-temp glue guns to build creations from cardboard tubes, assorted lids, film canisters, or whatever type of objects you can collect. You can have wood scraps the children can saw and nail together. (Appropriate supervision and safety guidelines are needed.)
The students can try building toothpick structures. They can experiment with materials to connect the toothpicks (marshmallows, play-doh). How tall can they build? What different techniques did they discover? What happens if they use straws or popsicle sticks? (I've used graham crackers for building structures, but they take more assistance and patience.)
http://www.contractor.edu/heavyequip...equipment.html had some ideas.
Books:
Curious George and the Dump Truck by H.A. Rey
Diggers by Fiona Watt
Digger (Machines at Work) by Nicola Deschamps
Dazzling Diggers by Tony Mitton
C is for Construction: Big Trucks and Diggers from A to Z by Caterpillar
Construction Trucks by Jennifer Dussling
Building Machines and What They Do by Derek Radford
Construction Zone Board Book by Tana Hoban
Architects Make Zigzags: Looking at Architecture from A to Z by Diane Maddex