Slump/Air Content/Cylinders
One of the classic concrete tests SME performs is a slump test. In a slump test, concrete is rodded into a cone in three lifts. The cone is then removed and the distance the concrete slumps from the height of the cone is measured. The slump is an indicator of the water/cement ratio, and if the slump is too high, the quality of the concrete may be suspect. Changes in the slump of the concrete between batches of the same concrete mix indicate a consistency problem.
Air content test measures the total air content in a sample of fresh concrete. Durable exterior concrete must be air entrained to provide resistance to damage through freeze-thaw cycles. It will not perform well if the air content is not correct. Improper air content can also affect the finish of interior slabs.
The project specifications designate design strengths for various types of concrete. Cylinders are cast, cured and then tested to verify the compressive strength is met. SME’s laboratories have temperature/humidity controlled curing facilities for proper curing of the cylinders, and our break machines are calibrated annually. We also participate in annual Michigan Department of Transportation (MDOT) testing of concrete cylinders to verity our test results are within acceptable statistical parameters.
Concrete Maturity
SME uses maturity testing to quickly and repeatedly predict the compressive strength of in-place concrete based on the temperature history of the concrete. Maturity testing can prevent delays to the project, and may improve the schedule of the project. Maturity testing can also monitor the curing temperatures of the concrete to verify the concrete is adequately protected from the hot or cold environmental conditions.
SME owns and operates thermal monitoring equipment with remote sensing capability. Temperature information can be obtained remotely and transmitted back to the construction site using an internet connection. This system has been used to document concrete temperatures for mass concrete placements. Extreme differences in temperature between the interior and edges of mass placements can result in thermal cracking of the concrete. Monitoring of the concrete temperatures can provide the contractors with the information that they need to adjust their concrete protection procedures.
Floor Flatness
SME uses Face dipsticks to document the floor flatness (FF) and floor levelness (FL) of floor slabs. The FF and FL numbers are used to evaluate the contractor’s finishing procedures and determine whether the concrete surface complies with the project requirements.
Evaluation and Repair
Through specialty nondestructive and destructive testing, SME can evaluate and recommend repairs, provide repair documents, and monitor repair activities for concrete structures and components.