Water can pose a major threat to your concrete, however, it’s a danger that is often overlooked. To guarantee that the lifespan of your concrete will not be reduced due to water damage, you will first need to understand the four ways in which it causes this damage.
1. Chemical attacks
Chemicals like chloride and sulfates can have an extremely detrimental impact on your concrete. Repeated exposure can corrode the steel rebar that lies within the concrete, causing the structure to collapse.
There are two ways that sulfates in solution can attack your concrete: physically and chemically. Sulfates produce chemical changes in the cement, weakening its bond between the aggregate and cement paste and cracking over time.
Sulfate solutions are known to damage concrete through crystallization and recrystallization as well, also resulting in cracking. Both forms of sulfate attacks are a product of high-sulfate ground waters and soils, as well as pollution and seawater.
There are three ingredients that cause the corrosion of reinforced concrete: water, reinforced steel, and oxygen. Removing even one of these factors is all that’s needed to prevent deterioration, which is why corrosion in dry concrete is so hard to find.
Unfortunately, when chloride ions are present, this is no longer the case. Chlorides destabilize the protection surrounding the steel rebar, and once this protective layer is gone, corrosion occurs. If you live near ocean water or in an area that de-ices its roads, your concrete may be at risk of chloride exposure and deterioration.
Fresh concrete provides steel rebar with the ideal corrosion protection because it contains free lime. Over time, however, atmospheric carbon dioxide creates carbonation that converts this free lime into limestone, which eventually corrodes the internal steel.
3. Constant Freezing and Thawing
Constant freeze/thaw cycles can cause concrete to crack. Frozen water takes up almost 10% more room than liquid water, and this constant change in water volume within the concrete will cause it to crack. This process is a never-ending cycle, and the cracks will only allow for more water to seep in and snowball into bigger and deeper crevices.
4. Alkali-Aggregates Reaction (AAR)
Over time, specific aggregates can react with the alkali hydroxides in concrete and cause the concrete to slowly expand and crack. This is known as an alkali-aggregate reaction (AAR).
There are two types of AARs: alkali-carbonate reactions (ACR) and alkali-silica reactions (ASR). ACR is typically a rare find because the aggregates that are vulnerable to this phenomenon are hard to come by and not usually suitable for concrete.
In ASR, the silica within the aggregates reacts with the alkali hydroxide in concrete and forms a gel that expands as it absorbs water within the concrete. As this gel expands, the concrete cracks.
When you choose the concrete contractors at Port Aggregates, you can rest assured that your concrete will be the highest quality and most durable on the market. With over 40 years of experience in the industry, our professionals will get the job done right the first time. Contact us today to request a quote!