Effect Of Magnetized Water On The Properties Of Concrete By Two-step Mixing Technology

Today,as the second largest consumption entity after water,cement concrete is still the most widely used material in civil engineering,which plays an irreplaceable role in the development of society.With the theme of modern green environmental protection and energy saving put forward,increasing the strength of cement mixture,saving cement consumption and reducing project cost are paid more and more attention.Therefore,this paper starts with the physical properties of water,and studies the influence of magnetized water on the comprehensive performance of cement concrete based on the two-step mixing techn ology by the method of theoretical analysis and experiment.The main contents of this paper are as follows:1.Theoretical analysis of water molecular structure and water magnetization mechanism.Firstly,the structure of single water molecule and the structure of water molecule cluster were analyzed.And then the magnetization mechanism of water was explained through the polarization effect of magnetic field and the change of magnetic field on the structure of water molecule.Because of the effect of magnetic field,the hydrogen bond of water molecule is elongated or broken,and the large water molecule cluster becomes small water molecule cluster or single water molecule.The physical and chemical properties of water are changed,and the activity of wa ter is enhanced.2.Based on the traditional concrete mixing technology,the macro mechanism and micro mechanism of concrete were analyzed.The two-step mixing technology improves the dispersion of cement particles and the activity of cement.The cemen t particles can be fully hydrated,which makes the next two-step mixing with aggregate easier to mix evenly,and then the workability and strength of concrete were improved greatly.3.In this experiment,the self-made permanent magnet device was setup to magnetize the water.The strength grade of the designed concrete is C40,and the comparative tests were carried out to study the influence of magnetized water on the performance of cement concrete by using four kinds of magnetic field strength,namely,0.6T,0.8T,1.0T and 1.2T,three kinds of water treatment speed,namely,2.33m/s,2.63m/s and 2.73m/s,and three kinds of mixing speed of cement paste.Compared with that of mixing with tap water,the test results show that the fluidity of cement paste was i ncreased by 37.73%;the concrete density was increased by 1.61%;the lift rate of concrete slump was increased by 27.78%;the 3d,7d and 28 d strength of hardened concrete were 33.9%,12.2% and 13.5%,respectively;on the premise of meeting the basic design strength,the cement consumption was at most reduced by 10%;for different test conditions,the value of electric flux decreases with the increase of water treatment time,and the permeability grade of chloride ion was low,which showed that the concrete mixed with magnetized water could effectively improve the chloride ion resistance of concrete.