Westshore Consulting has a dedicated staff of inspectors and material testers that are ready assist you in your construction project. It is important to know the components of the concrete mixture to ensure you are receiving the best product for the price you pay. The only way to guarantee you are receiving the strongest and most durable concrete for your project is to have it tested just prior to placement.
Testing Portland Cement Concrete
Many state and local governments have adopted a set of standards that require new concrete to be tested prior to being placed on the job site. The most common tests record the air content, slump, unit weight, and compressive strength.
Measuring the air content within concrete will help ensure that the concrete can withstand the difficult freeze-thaw cycles common to our Michigan climate. The in-place air content will inevitably be lower than the tested value due to losses during placement and finishing but the loss is minor and is ignored in most cases. Having air within your concrete ensures that water within the concrete has air pockets to expand into when it freezes. Without air pockets to contain the expanding ice, small fractures can form and over time the fractures compound to form large structural cracks. Having too many air voids within the concrete will make the concrete resist free-thaw very well, but will diminish the overall compressive strength. The chemical that creates the entrained air within the concrete is one of the most expensive ingredients in the mixture, despite only a couple dozen ounces being used. It is this cost and complexity of the mixture that can lead to concrete being produced that does not have a sufficient air content.
Slump is a test to measure the consistency of the concrete. A concrete mix that is too dry or has a low slump may result in large voids within your final product that can affect the appearance or even the overall strength. Negative effects can happen when the concrete has a slump that is too high as well. A concrete that flows too easily can have its components separate. The stones can settle to the bottom of the forms and the top of the concrete can become brittle and susceptible to premature deterioration.
Unit weight measures the weight of a known volume of fresh concrete.
Lastly, the compressive strength of the concrete is measured by casting a cylinder using the fresh concrete. This cylinder is taken to a lab and broken after curing (resting) for a specific number of days. Westshore has the facilities for curing and breaking the concrete cylinders. If the cylinders broken do not average to meet the strength required, then the initial mixture of the concrete should be investigated.
For more information, contact Wade VandenBosch at (231) 777-3447 or [email protected].