A Review After the First Month

We poured the prestressed slab for the new gantry crane bay four weeks ago. The client, a medium-sized fabrication shop, needed a floor that could handle a 35-ton overhead crane with dynamic loading from repeated lifts and movements. The existing floor was a standard reinforced slab that had started cracking under the previous lighter crane.

Our team designed a 280mm thick post-tensioned monolithic slab with a high-strength concrete mix (C50/60). The pour was done in a single shift to avoid cold joints. We used a chemical admixture to reduce shrinkage and improve early strength gain. The client's project manager was on site for the entire pour and asked detailed questions about the tendon layout and stressing sequence.

After the first month of operation, the floor shows no visible cracks or deflection. The crane rails were installed directly on the slab using epoxy-grouted bolts, and the alignment has remained within 1mm tolerance. The client reported that the crane moves smoothly across the bay without the vibration they experienced on the old floor. They have already started planning a second bay expansion and asked us to quote for a similar slab.

The main feedback from the client was about the curing process. We used wet curing with burlap and plastic sheeting for seven days, which required coordination with their production schedule. They appreciated the advance notice and the fact that we adjusted the curing plan to work around their weekend shutdown. The only minor issue was a small area near a column where the curing compound was applied unevenly, but this was resolved with a surface sealer application.