Can you put a new slab on top of the old slab?

A 30x50-foot pad I recently poured has quite a bit of cracking. The pad did not have expansion joints or rebar. This was later fixed with expansion joints. What are my options when it comes to pouring another pad on top of the existing one?
 
If you are thinking about overlaying an existing slab, even though we do not know what caused the initial cracking, consider these points:

1. The concrete pad overlay can be applied over an existing slab.

 

1. The overlay on the existing structure adds extra height and weight.

 

1. A polymeric overlay, asphalt, or epoxies are possible overlays. Follow the manufacturer's instructions for the preparation and application of an epoxy, latex, or portland cement overlay. A concrete overlay will not fix cracks caused by improper sub base preparation or settlement.

 

1. Overlay reinforcement (welded wire reinforcement or #4 rebar) should be added if old cracks are still active. Reflective cracks will be held together by this reinforcement. Additionally, considering adding fibers to your overlay could prevent plastic cracking due to shrinkage.

 

1. Having a good slope on the overlay will improve drainage on the slab.

 

1. Although an overlay may keep non-moving cracks from propagating, the overlay won't prevent active cracks from escalating through the overlay. Bond breakers can be used over existing cracks to prevent them from reoccurring in the overlay.

 

1. Cracks can appear in the overlay if the plastic shrinks or dries out. To prevent cracking, finish operations should be timed according to the installation, so that the overlay does not dry too quickly. Drying shrinkage or tearing during finishing may cause cracks if the surface dries out. These types of cracks are more common in thin overlays. You can contact any concrete contractor Los Angeles if you have no confidence to do it on your own.

 

1. When possible, stay away from hot and dry periods of the day. Cover the overlay with wet burlap for seven days to cure it. When laying the overlay, try to have the slab near the temperature of the overlay material when cutting or tooling control joints. This should be completed within 4 to 12 hours in hot weather and within 12 hours in cold weather.

 

1. As a general rule, bonded overlays shouldn't be used over active cracks in a slab, as these will recur during the overlay.

 

1. The results you desire may require that you remove the existing slab, pour a new slab on top of the supporting subbase, and then finish by tuck-pointing the support beams.

 
If you are from Los Angeles and looking for the best Los Angeles Concrete Contractor for this work. It will be great because an expert can do this kind of work fantastically.