CONCRETE
Other Services – Asphalt Repair – Maintenance – Striping – Steel
TARC Construction, Inc. has decades of professional experience in parking lot maintenance. We have the answers to all of your asphalt and concrete needs.
Cracking
Cracking can be the result of one or more factors, such as drying shrinkage, thermal contraction, subgrade settlement and applied loads. Cracking cannot be prevented but it can be controlled.
Solution: Prepare subgrade properly, compact all loose soil underneath the concrete slab. Slope the subgrade for proper drainage. Design a flexible concrete pavement that can accommodate load and movements. Use the proper strength of concrete for the job with properly placed tension control joints. Do not overwork the concrete surface. Avoid rapid drying conditions.
Scaling
Surface scaling occurs when the concrete surface breaks off to a depth of 2 inches and keeps peeling away. Causes for scaling vary and are dependent on surface strength, curing procedures, water seepage, air content and air entrainment. Concrete subjected to use of de-icing salts combined with freeze-thaw conditions is prone to scaling. Chemicals such as ammonium nitrate and ammonium sulfate, which are components of most fertilizers, can cause scaling as well.
Solution: All factors have to be taken into account when designing a concrete mix in order to produce concrete with a workable slump. For best results concrete is finished at the right time, once all water has been evaporated. Cure concrete adequately without using salt or other chemicals during winter. Don’t overwork the concrete surface. Avoid using a vibrating screed on high slump concrete.
Crazing
Crazing refers to the development of random and interconnected fine cracks in a concrete surface. This generally occurs when the slab is damp the day after placement or within the first week. Crazing of concrete is caused by an overly wet mix and poor or inadequate curing and is the result of cement paste rising up to the surface.
Solution: Use a moderate slump concrete without bleeding and segregation. Complete the finishing process when all water has evaporated, do not dust cement on the surface while water is present, and do not sprinkle water over the concrete while finishing it. Use a broom finish instead of using a steel towel. Cure concrete adequately so it can retain the necessary moisture for the hydration process.