Sand is sand to most people. Dig it, truck it, and get to work. But if you’ve seen a concrete pour fail or a structure that settles, you know that it’s not that simple. Construction sand influences the strength of structures and how long it takes to get a project done. The difference between good sand and bad sand will manifest in the ways listed below.
What Makes Construction Sand Different
All sand is not created equal when it comes to construction. Beach sand has salt and organic material in it that makes concrete weak. Desert sand grains are too smooth and round to bond properly. The sand used in construction has specific qualities that normal sand does not.
The sand’s particle size is an important factor that most people overlook. Construction sand has to be just the right size to pack together but leave enough room for the cement paste to bind properly. If the sand is too fine, it increases the amount of water and cement needed. Too coarse, it introduces weak points into the finished product.
The shape of the grains of sand also plays an important part in the performance of construction sand. Angular shapes that are not smooth bond together better than smooth pieces of sand. River sand is the best form of construction sand for this reason, as the flowing river creates an ideal texture without smoothing the sand grains out too much.
The Issues Poor Quality Sand Creates
Using poor-quality sand creates issues that are not always obvious. Concrete made with poor-quality or the wrong type of sand takes much longer to cure properly. It may look good for a few weeks, but it will crack after months or years. The mix will never reach the intended strength and will not perform as expected.
Moisture content can create issues too. Sand that is too wet throws off the mix ratios, resulting in concrete that is weaker than expected. Sand that is too dry does not mix properly and leaves lumps of unmixed aggregate or cement in the concrete. A professional supplier understands how to achieve consistent moisture levels in sand with every load they deliver.
Contamination is another issue that often does not get the attention it deserves. Clay, silt, and organic material in construction might not seem like a problem, but they can cause serious issues with how bonds set in a cement mix. Even a small amount of clay will weaken concrete significantly. Organic material is far worse and will cause the concrete to rot from the inside.
Why Testing and Certification is Important
Testing is often a step that contractors skip to save on time and costs, but it should not be an option. Sand used in critical applications should be properly tested for contaminants, gradation, and moisture content before it is allowed on-site or mixed with other materials.
Gradation testing tests whether sand particles fall within the expected size range. An ideal mix will have all sorts of particle sizes that fit perfectly together. If there are too many of one type of particle, it creates strength and workability issues. The results will tell the contractor whether the concrete mix design needs adjusting.
Silt and clay testing checks the contamination levels in sand. The limits are set at different levels for different applications. If levels are exceeded, that means washing the sand before use or avoiding its use in structural applications altogether.
The Economics of Quality Sand
This is where contractors usually create a false economy of scale using cheap sand to save their clients money on construction projects. Cheaper substandard materials may cost contractors more than they expect, though.
Weak concrete will always require remedial work to be done after the fact. Concrete that fails inspections will set contractors and their clients back in terms of time and cost. Fantastic construction sand makes economic sense at the front and back end of every building project.
Quality sand also makes construction easier from a financial point of view. It mixes well every time and performs consistently across all applications once it has been set. People who work on the project spend less time trying to use problematic concrete and more time finishing the job well and fast. This matters a great deal when timelines are tight.
The difference in price between good quality sand and poor-quality sand is not nearly as vast as the difference in performance that good quality sand affords. The extra cost of properly validated materials is worth every penny in the long run.
Finding a Good Supplier
Finding a good supplier is not something that happens overnight, but the process is worth it. Professional suppliers regularly test their sand for contaminants before they deliver it to construction sites.
Professional suppliers understand how to ensure the same quality on every load. They use consistent quality control measures for every delivery, which means that the mix design is correct for every part of a project.
Sand used in construction may seem boring, but it is critical to ensuring that everything else works as it should. Building with proper construction sand designed for its intended use means fewer headaches down the road, saves a project more money over its lifecycle, and builds structures that last forever. Those who know this will create better projects and enjoy doing so in the process.
