For specific restoration repair(s) by component:
Columns:
Columns are one the primary supports(vertical) for structures to transfer weight and load to the foundation and then ground. Deterioration of columns can cause minor to major loss of structural integrity. If extensive deterioration of the columns is found, we install shoring to remove the live and dead loads to facilitate the repairs. When a structure has section loss in the cross-section of columns it compromises the integrity of the entire structure and shoring is mandatory. If the columns have marginal section loss the shoring becomes significantly less as well as having the ability to perform the fix in phases. We have experience from repairing corroded corner bars to shoring the entire structure for complete column replacement.
Beams:
Beams are the other primary support(horizontal) for the transfer of weight and load to the foundation and ground for a structure. Beam repairs can be varied in their complexity. A way to spot beam structural failure is concrete delamination, as well as cracking. We will typically see concrete delamination up the sides of beams at the stirrup locations and on the bottom corner bars; if the delamination is significant by square footage, we would immediately install shoring. We are one of the few companies that have the experience and technology to actually replace post-tension beam tendons inside their jackets. We have successfully completed post-tension beam tendons from the Kansas City performing arts center, towers in Chicago and several locations in St. louis, Missouri.
we have replaced entire beams which requires extensive shoring as well as supplemented beams with new beams next to them.
Another type of beam project is adding supplemental beams when there is a desire to increase load capacities, such as when an office building adds a library.
Slabs:
There are mainly three types of slabs – post-tensioned, conventionally reinforced, and a hybrid slab which has tendons in it for crack control at the time of placement.
- Post-tension slabs: there are numerous post-tension systems that have been installed over the decades – we have fixed them all – button-head systems, .5 strand systems, .6 strand systems, 20mm rod systems. At issue with post-tensioned slabs is the extent of the shoring required – typically we would need the entire length of tendon shored if there is more than a handful of repairs; we would usually phase work like such as this to keep the impact on tenants to a minimum.
- Conventionally reinforced slabs: there is a great deal more concrete delamination work in a conventional deck due to the quantity of reinforcing steel susceptible to the attacks of corrosion; not structural issues as much as a liability for tripping hazards and falling debris; we not only repair these slabs but install several systems to prevent future issues.
- Hybrid slabs: very similar to convention slab repairs with the exception of post-tension tendons installed which are occasionally load bearing; we fix these slabs similarly to the conventionally reinforced slabs; these are not as frequently found but they do occur.
Carbon fiber (FRP):
Carbon fiber is providing a cost-effective solution to traditional structural integrity repairs. Carbon fiber comes in plates, fabric or rods. It is used to strengthen members of a building that need help either from a load capacity standpoint or seismic upgrades. This product is becoming more common as more engineers become knowledgeable in its uses. We have successfully submitted it as an alternate repair method where the cost savings are significant enough to warrant its use to receptive audiences and implemented it on jobs.
