Work continues along the corridors in the basement and first floor at the north end of Daniels. There is now a doorway in the middle of the entryway to the demo lab and the concrete-block wall on the first floor near where the vending machines used to be is partially demolished. This week we expect the rest of the wall to be removed in preparation for pouring a concrete floor that will widen the first-floor exit corridor from the Daniels north stairway toward the loading dock. Exit-arrow signs, two exit lights, and an emergency light have been installed in this corridor and signage outside the building shows the exit path, which goes toward the loading dock and then out the loading-dock driveway to Charter Street. Unless you need to exit through them in case of an emergency, please avoid the north corridors in Daniels on the basement and first-floor levels and warn others to do the same.
More construction materials have been delivered to the mock-up of the exterior of the new tower in parking lot 45, across Mills Street from the Charter Street power plant. The rows of spheres surrounded by a mesh of steel reinforcing bars are an interesting feature of construction in our new tower: concrete floors will be filled with these spheres to reduce the mass of the building. In a poured concrete floor, the steel rebar at the bottom is in tension while the concrete at the top is in compression. The middle of layer does not contribute significantly to strength and can be filled with hard-plastic spheres a bit larger than a basketball, reducing the mass of concrete. Because 35% less concrete is used, greenhouse-gas emissions are reduced significantly.
Work in the sub-basement of Daniels has been slowed because asbestos-containing material was discovered below the concrete floor. Apparently this material was installed when Daniels was constructed in the late 1960s to prevent water from coming up through the floor. Fortunately, the asbestos is not in a form that releases dust and there is no need for complete isolation of the sub-basement area where the floor is being excavated; however, the concrete slabs must each be wrapped to prevent escape of asbestos before they are hauled to a hazardous waste landfill. This will slow excavation of the sub-basement for installation of utilities connecting to the new tower.
On the Mills Street side of our building gravel has been backfilled around the south area well, covering utilities ducts that were recently installed. Backfilling required use of a diesel-powered machine with more fumes coming into the building. The workers are doing their best to prevent intake of diesel fumes, turning machines off when not in use and warming up machines well away from the Daniels air intake (which is at the first-floor level next to Seminar Hall). The north area well remains open to allow concrete slabs to be removed and machines and equipment to go in and out of the sub-basement.
The tower excavation along University Avenue is significantly deeper. A steady stream of trucks enters and leaves the site at the corner of Mills St. and University Ave. The number of trucks was augmented by those bringing in backfill for use along Mills St. Continue to be vigilant in these areas and watch for construction workers directing traffic.
Remember that there will be a short shutdown of the entire chemistry complex (Shain, Mathews, and Daniels) tentatively scheduled for Tuesday, March 19. Nobody should be in the building during the shutdown from 2 am until an all-clear announcement (which probably will happen at 12:00 noon). See an email dated February 27 from Bob McMahon to everyone for details of the shutdown and make certain that your research group’s labs are prepared for the loss of ventilation.
This information is up-to-date as of Friday afternoon. Email bulletins will be provided as needed.
John Moore and Bob McMahon