The world is full of concrete mix failures. They may not be obvious –or at least, not immediately obvious– to the casual observer. But every contractor, every builder and homeowner should know what five common concrete mix defects look like and how they can be fixed.
1. Air entrapment: Air bubbles in the concrete are a common mix failure, particularly when it’s fresh poured. The bubbles are trapped in the form of small voids that can later lead to cracks in the concrete and serious problems with compression, settlement and other structural issues.
2. High water content: As water gets absorbed into the concrete, it changes its consistency, causing it to shrink or expand when stressed or expanded by other forces like heat or freezing/thawing cycles. This leads to separation of different size aggregates, which can cause cracking and other problems as stress levels increase or decrease over time.
3. High cement content: Excessive cement in the mix will increase its weight, which can result in expansion or contraction as temperatures rise or fall during extreme weather conditions…
4. Wrong amount of sand: The amount of sand needed for a particular application depends on a number of factors, including how much space is available for aggregate flow and where you intend to live in the
There are five surprising causes of concrete mix failure. Any concrete contractor should be able to prevent them.
• The wrong type of cement is used.
• The wrong amount of cement is used.
• The wrong ratio of sand to cement is used.
• The wrong mix method is used.
• The wrong compaction method is used.
Concrete is the most widely used building material in the world. It accounts for at least 25% of all building construction, so it is vital to understand how concrete works to ensure its future safety.
When building a house, the designer will specify what kind of concrete mix the builder will use to make concrete. The construction worker may very well not know that there are a large number of concrete mix defects that can cause the concrete to fail in unexpected ways.
There are many other factors that can cause concrete to fail including water, air, and temperature and there are also many different types of concrete mix defect and each type has a different way that it can fail.
If you want to learn about how to prevent your own house from being damaged by a defective concrete mix, then this blog is for you! In this blog you will find out the five most common causes of failures on a DIY job site.
I hope you enjoyed reading this post and I hope it inspires you! If you have any questions or comments please send me an email via my website: http://www.cementmixdefects.com/
A cement mix will fail if it is not mixed properly. Mixing the right amount of ingredients at the right time and in the right manner is crucial.
If you are new to this, you may want to read several articles on the subject before starting your project.
The article “How to Mix Concrete” from the American Concrete Institute provides a good basic explanation of what mixing concrete is all about. The article “How to Mix Concrete” from Concrete Network has more detail about specific problems and some good information about concrete mix design. The article “How to Mix Concrete: A Step-by-Step Guide for Beginners” from Popular Mechanics gives a very basic overview of how concrete is made and mixed.
A construction company in western Pennsylvania has been fined $500,000 for failing to keep proper records after it re-ran a batch of concrete that failed and began pouring new concrete on the same site. The state Department of Environmental Protection levied the fine against Penn Harrisburg Corp. and ordered it to seek reimbursement from the contractor whose work it was inspecting.
The DEP found that Penn Harrisburg Corp., which manages roadways in York County, did not have records showing how much concrete was added to the mix or what type of substitute cement was used. The agency also said the company did not have records showing whether the mix was properly blended or if water was added to the mixture.
The DEP found that during work that needed to be done at a West Manchester Township parking lot, Penn Harrisburg poured seven batches of concrete: five were improperly blended and two had insufficient cement. The agency said the poor quality of those two batches resulted in cracks about two inches wide and about 30 feet long in roads being built for the National Rifle Association’s annual convention.
Concrete is an interesting material. It is not a good choice for making structures that will get wet every day, or that will be subject to seismic shocks or frost heave or salt spray or snow-drift. If it has to be exposed to any of these things, the builder will do better with a different kind of building material.
Concrete is hard and strong, but it is brittle. If a crack forms in concrete near one of the cracks in the form of a V-shape, then that V-shaped crack can propagate easily along the most likely direction of crack growth: at right angles to the first crack. That’s just how cracks work; they are usually pretty easy to propagate once they’re formed.
If you have cracks in your concrete, you can fix them by filling them with cement paste, but if you have multiple types of cracks, then you’ll probably need more than just one kind of filler.
When concrete is poured, it shrinks as it sets. This shrinkage can cause problems. For example, if the concrete is placed in a column too tall for its width and the column’s top surface is uneven, then the concrete present at the top will be more shrunken than below. If these shrunken areas are not evenly distributed, they can become cracks. When a crack appears in a concrete slab, water can get into the voids and cause corrosion of steel reinforcing bars in the slab behind. If enough water gets into the voids and is allowed to remain there for long enough, then rust spots form on the steel reinforcing bars.
When a sloping tie beam is exposed to severe seismic forces, it will buckle and twist. When this happens, the tie beam will break at that point – usually at one of its end ties – and fall to one side with a loud bang.*