M&M Precast, Inc.

• Project: I-66 Highways for Life• Location: Rt. 50 Ramp (East) off I-66 – Fairfax, Virginia• VDOT Project No.: (FO)0066-029-767, M501• FHWA #: IM-066-1(322)• Contractor: Lane Construction Corp.

– Superintendent: Erich Brown• Client: Virginia Department of Transportation

– VDOT Coordinator: David P. Shiells, P.E.• Challenges:

– Gain approval [at the 11th hour] for a HPC mix design– 224 Slabs – everyone geometrically different (no 90o corners, some warped)– Must be delivered in proper sequence – one wrong slab and the project is shut down– Extremely tight production and delivery schedules– New product with a new and untrained workforce– High profile project with persistent scrutiny

Proper Set UpProper set up is the key to maintaining an efficient, safe, and quality conscience environment. Having the raw materials,

tools, and shop drawings available at the source saves time and helps eliminate confusion.

Raw Material OrganizationDowels bars, pails filled with PVC sleeves, and pre-wrapped

dove-tail inserts at each table saves valuable time.

Information StationDaily schedules and cut sheets keeps the crew informed and

valuable information readily available.

Quality ControlSince we had 224 Slabs that were all different geometrically, quality control checks

were crucial:• Tables were checked after initial rail layout and table height adjustments.• Tables were again checked before casting:

– Dimensions– Warp adjustments (with auto-level)– Rebar placement– Dovetail slot placement– Lifting insert placement and bolt adjustment– Magnet placement and engagement– Dowel depth

• Slabs were checked during concrete placement and after concrete finishing• Post-pour checks were conducted after curing • Slab stacking sequence was pre-arranged and checked by QC• Slabs were again checked after trailer loading for:

– Dimensions– Dunnage placement– Finish– Slab identification

Required toolsClean and ready for production is pivotal.

Concrete FinishingUsing a roller screed ensures meeting slab thickness and flatness

requirements.

Concrete FinishingUsing a bull float to achieve a smooth consolidated finish.

Pre-loading Trailers for DeliveryHaving trailers pre-loaded and QC inspected is the key to on-

time and quality insured deliveries.

Slab RemovalOn site – First night of slab installation

Dowel Drilling & Sub-grade Preparation

Sub-grade Checks and Slab PlacementAlthough the finished roadway looked good, several cracks

formed due to improper sub-grade levels. The sub-grade levels in the corners, where hand finishing is required, was up to 2”

lower than proper grade. I suggest immediate grouting to help eliminate this possibility.

Slab Placement and Section Completion