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massive rebar grid laid out in the center part of the excavation site

The Henry K. Oliver Project in Lawrence achieved a significant milestone on Saturday, March 11th with the placement (concrete pour) of the first section of the building’s mat slab. The mat slab is a 4-foot thick, reinforced concrete placement located 18’ below grade, serving as the foundation for the Oliver School’s new 5-story addition. The first placement was roughly 10,000 sqft, utilizing 1,360 cubic yards of concrete delivered on site by 125 concrete trucks. Logistics was the biggest challenge for the project, ensuring that the number of trucks could get in and out of the required locations safely and within the necessary timeframes. The placement was planned for Saturday to ensure the project’s sole use of multiple concrete plants and to avoid traffic impacts to the surrounding community. 

In the drone video shown above, you can see the beginning of the mat slab placement, which used three remote-controlled pump trucks with over 150 feet of reach to place the concrete in layers throughout the slab’s footprint. In the video you will also see the reinforcing rebar, which are steel rods that serves to strengthen the concrete and helping it resist cracking. Over 280,000 lbs. of rebar were installed for this first placement. The wooden structures seen within the rebar are to form plumbing trenches within the mat slab.


Click here to see aerial footage for the construction site for Mid-March 2023

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