Concrete can be extremely durable and with low maintenance if if it is prepared properly, wind water and heat are the factors which can be registered by the concrete if the quality of concrete is good on the other hand the cracked concrete is a different type.
As seen during the construction site the main culprit of cracked concrete can be known as dry shrinkage cracking,In the curing this is one of the the main headache for the the construction and also creating bigger issues in the future.
Reason for concrete shrinkage:
Minimum water required for concrete to hydrate and gain strength over time is 26 gallons per yard and extra water over 26 gal can be only used in concrete mixture for workability and pumpability.
But sometimes while construction some extra water is added which will not be used for hydration process so the water will be bleed out from concrete as the water leaves out the concrete it creates volume change so it can be called as dry shrinkage. If the concrete will not be strong enough during the curing process against the tensile forces then it will crack.
Reason for concrete shrinkage causes cracks:-
you can find many reasons for concrete shrinkage to cause cracks
Plastic shrinkage is one of the main reason in which on a hot and windy day the water on the surface of concrete male loose at a faster speed than concrete can resist and it will cause shrinkage. In the curing process it can occur in in initial setting to the final setting. The cracks will appear only on the surface not on the full depth.
Change of volume of concrete can a occur when concrete goes past final setting time and also the extra water which is not used for hydration will withdraw from the concrete. It is generally full death type of cracking in and it can be managed by placing joints of 8 foot to 12 ft square layouts.
Thermal differential cracking the surface at the top will dry much quicker than the bottom of the concrete,This type of cracking is very typical as the cracking will show wide gaps and very rough ages in appearance.
Shrinkage can be prevented by following measures:
Mix design,water cement ratio is very critical for reducing potential shrinkage in the future it should be maintained properly.
If workability needs to be improved go for the admixture not water.
But you have to you understand that some of the condition will affect the concrete and it will be high heat, low humidity. The subgrade should be moistened and should not be reminder dry as this will cause water to live quickly.
If the rebar are used it needs to be cool down before placing, it can be assistant by curing immediately surface of concrete with water.
G3 quality expertise is one of the method of placing the concrete where we can create checklist to help lower the possibility of cracking in the construction project.
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