M&M Precast, Inc. Project: I-66 Highways for Life Location: Rt. 50 Ramp (East) off I-66 – Fairfax, Virginia VDOT Project No.: (FO) , 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 11 th hour] for a HPC mix design – 224 Slabs – everyone geometrically different (no 90 o 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 Up Proper 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 Organization Dowels bars, pails filled with PVC sleeves, and pre-wrapped dove-tail inserts at each table saves valuable time.

Information Station Daily schedules and cut sheets keeps the crew informed and valuable information readily available.

Quality Control Since 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 tools Clean and ready for production is pivotal.

Concrete Finishing Using a roller screed ensures meeting slab thickness and flatness requirements.

Concrete Finishing Using a bull float to achieve a smooth consolidated finish.

Pre-loading Trailers for Delivery Having trailers pre-loaded and QC inspected is the key to on-time and quality insured deliveries.

Slab Removal On site – First night of slab installation

Dowel Drilling & Sub-grade Preparation

Sub-grade Checks and Slab Placement Although 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