When Portland cement is mixed with water a chemical reaction takes place. The cement does not simply "dry" it reacts with the water to form crystals. These crystals bind the materials in a concrete mix firmly together and harden into an incredibly strong rock like mass.
It takes some time and the optimum temperature for the best crystal formation in the cement. If the temperature is too low crystals will not form well or will form very slowly. The concrete will dry and harden slowly and will not be as strong as concrete formed at an optimum temperature.
When you manufacture concrete blocks or any other concrete products the temperature should not drop below 40 degrees Fahrenheit (5 degrees Centigrade) and ideally should be 50 degrees (10 degrees Centigrade) or higher. This allows the cement crystals to form properly and bind the concrete mix strongly together.
You will often hear the term "curing concrete" used. This simply refers to the time which the concrete needs to form an optimum bond after it has been mixed with water. In other words this is the time needed for the concrete to reach maximum hardness.
The surface of the concrete needs to be kept damp during the curing process or the outer layer of the product will not harden properly and could crumble. This is why concrete is sprayed down with water while it cures.The concrete must be kept wet to cure properly.
The strength of the concrete depends on the proper growth of the cement crystals within the mix. If the crystals don't grow properly due to the wrong amount of water being added,or to the temperature being too low,the concrete will not have the full strength that it should have. You will be depending on your concrete structures to withstand all kinds of weather and temperature changes. In order to achieve this you need to have optimum crystal growth within the concrete mixture.
For best crystal growth you must have the correct proportion of water in the concrete mix. If there is insufficient water the crystals will not grow. If the temperature is too low the crystals will not grow well either. If the temperature is too high the crystals grow too quickly and the chemical reaction produces heat which can lead to cracking of the concrete product.
With the correct proportion of water in the mix the crystals grow properly and bond the concrete by intertwining round the sand and gravel. When you make concrete products you need the curing to take place as quickly as possible to get your products delivered to the customer. This is achieved by using the correct concrete mix with the right proportion of water added to it. In addition the surface of the concrete must be kept damp and the temperature at above 40 degrees Fahrenheit.
Another factor which determines the strength and hardness of the finished concrete product is proper mixing of the ingredients. If the ingredients are not thoroughly mixed there will be differing degrees of hardness in various parts of the finished product. Needless to say this is something to avoid at all costs.
The dry ingredients of the concrete mix should be thoroughly mixed before adding water. This is particularly true if you are mixing the concrete by hand on the ground. You should very thoroughly combine all the ingredients of the mix into a homogeneous mixture before adding the water. Using a mechanical concrete mixer helps to make sure that the concrete is thoroughly combined before pouring.
Making concrete blocks and other concrete products is an excellent business which can be started with very little cash. All that is required is hand made molds which you can make from plywood and sheet metal. One person can easily turn out 100 blocks per day with these molds. Plans with instructions are readily available.
Would you like to know how to start your own concrete products business,part time from home,with very little cash? Would you like to know how to build a concrete block making machine at low cost?You will find lots of free information and resources at MAKE CONCRETE PRODUCTS.
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