First observations and scientific works on application of magnetic fields in the production of cement, ceramics, brick, casting forms, etc., were carried out in the former USSR, in 1962.
Other countries, including USA, almost did not participate in this field until 1980. However, convincing and irrefutable results were received by authorized Soviet and Russian scientists, including scientific-research institute “VNII Jelezobeton”. These results were on the application of magnetic fields in construction industry and made scientists of America and other countries, change their views on magnetic technologies.
In the last few years, successful experiments that involved using magnetic technologies in construction industries were carried out. Experiments in other fields were also carried out by Baylor and Tulane Universities, by Standard Oil and Amoco Oil companies, by the Department of Defense USA and the Naval Construction Battalion Center. Obtained results allowed them to successfully use magnetic treatment of solutions.
Government of the Russian Federation issued a decree No1058 on 14 October 1993 on a Federal Program “Application of magnetic fields in the national economy”, based on which, State Construction Committee of Russia, created a range of documents, ordering their organizations to use magnetic technologies. This decision was made in order to economize on cementing and ferro-concrete reinforcement, to increase cement product’s strength, to increase the life of constructions and to intensify various technological processes.
Brief description of the results, which are possible to obtain using magnetic technologies
In some cases, during production of cement and other construction materials, there is a deficit of fresh water. Many years’ observations and practice show that application of our magnetic systems allows using salty and even seawater. When using magnetized seawater for cement kneading, cement strength increases by 30-40% and the economy on cement becomes 14%. However, application of seawater requires conducting certain procedures in order to eliminate incrustations in water-pipes and water-pump stations. Even though, this problem can be solved by additional installation of magnetic devices in water-supply system.
While transporting concrete mixtures on long distances, its plasticity decreases by 30-40%. This leads to concrete’s inability to lay properly and increases energy expenses when electro-mechanical vibrators are used. In this case, it is wise to use our magnetic system, “KONMAG”, designed for magnetization of ready-made concrete at industrial areas. One way of using “KONMAG” is shown on fig. 1. This technology allows not only to increase concrete’s plasticity but, at the same time, allows to increase its resistance to pressure by 15-25% and tensile strength by 30-40%.
Theoretical model of impact of water, treated by magnetic field, on concrete mixing
One of the basic characteristics of magnetically treated water, which has major importance in concrete making, is its pertaining to colloidal particles and solutions. Like ion solution (colloidal cement solution is made with magnetized water), colloidal cement solution will contain colloidal particles, surrounded by a thinner dense layer of water mono-molecules as the number of mono-molecules drops at some regimen of magnetic treatment. Therefore, some reduction of water share in cement mixture is possible.
At the moment of fastening, there is a thinner hydrate layer between cement particles in magnetized water than in non-magnetized. Naturally, this thin layer will quickly react with the surface layer of particles, i.e. it will fasten quicker, but when hydrate layer is depleted, water diffusion inside particles stops due to lack of free water near the surface. At fastening the water, required for further hydration, water is forced out in the sample surface and from there its transfer to particles inside the sample gets very difficult. Due to this reason, cement (made with magnetized water), hardens quicker and gets strength faster on the initial stage. But, then, the speed of its hardening drops abruptly because it becomes difficult for water to reach particles. However, due to such process, porosity of cement rock reduces significantly and the final strength of concrete for compression and tension increases. Also laying of the concrete mixture becomes easier and significantly improves.
SOME EXAMPLES OF MAGNETIZED WATER IMPACT ON CONCRETE MIXTURE
Impact of magnetized water on concrete strength at compressing.
|Water||Materials consumption, kg/m3||Water/cement ratio||Hardness, s||Cone settling, cm||Strength for compression after warm- humid treatment, mPa/%|
|Cement||Crushed stone||Sand||Water||1 day||28 days|
Impact of magnetized water on concrete strength at tension
|Water||Materials consumption, kg/m3||Water/cement ratio||Hardness, s||Cone settling, cm||Strength at 7 days, mPa/%|
|Cement||Crushed stone||Sand||Water||For compression||For tension at breaking|
As is seen from the above examples, tension strength is always higher than compression strength. In other words, ratio between tension strength at breaking and compression strength in concrete made with magnetized water increased by 25%. It can be explained by a more homogenous lattice of new formations of hydrated cement minerals, mixed with magnetized water. It is worth mentioning that the same phenomenon happens in ceramic materials. Increased tension strength of concrete leads to an extra effect of saving cement, additives and thermal energy when magnetized water is used for concrete, for which tension strength is vital.
But even when compression strength is the main factor for concrete, statistically relevant confirmation of increasing ratio of concrete tension and compression strength allows to increase calculated resistance of concrete at tension in standards for designing concrete construction. It would reduce rods’ usage and the required value of their initial tension in elements of the first and second categories of crack- resistance. Requirements for horizontal rods, fixed as calculated for horizontal strength, for crushing and other cases would also drop. Reduction of rods’ usage is approximately proportional to increasing of concrete tension strength.