Study On Effect Of Auxiliary Vibration On The Properties Of Self-Compacting Barite Concrete

When the self-compacting concrete is applied in engineering,it is often difficult to achieve the ideal self-compacting effect due to the dense reinforcement of certain parts or the special-shaped structure,which hinders its popularization and application.In order to effectively solve this problem,the methods of auxiliary vibration of selfcompacting concrete are often used in the past.The self-compacting barite concrete has the dual properties of self-compacting and radiation protection,and it has good application prospects in shielding engineering.The density of barite aggregate in self-compacting barite concrete is higher than that of ordinary aggregate.If it is subjected to auxiliary vibration,it may cause segregation and affect the performance of concrete.The effect of auxiliary vibration on the performance of self-compacting barite concrete is studied to provide a reference for construction craft of self-compacting barite concrete.The orthogonal test was designed by changing the three parameters of poker vibrator voltage,vibrating duration and poker vibrator insertion depth.The layered segregation test,compressive strength test and radiation protection performance test shall be carried out for the vibrated self-compacting barite concrete,and the influence of auxiliary vibration on the performance of concrete shall be comprehensively considered;The distribution of aggregate in the hardened concrete section image was analyzed and calculated by using Image-Pro Plus software,and the main conclusions are as follows:(1)Auxiliary vibration has a great impact on the segregation of self-compacting barite concrete.When the concrete mixture is not vibrated,the layered segregation rate of concrete mixture is 1.06%,and after vibration,it is between 5.30%～26.58%.By adjusting the vibration parameters,the segregation of concrete can be controlled.The variation of vibrator voltage has the greatest impact on the layered segregation rate of concrete mixture.The optimal combination of vibration parameters in this test is that the vibrator voltage is 70 V,the vibration duration is 6 s and the insertion depth is 200 mm.At this time,the layered segregation rate of concrete mixture is 5.30%.(2)The layered segregation rate of coarse aggregate with different particle sizes is obviously different.The larger the particle size of the aggregate,the greater the segregation.Under the condition of changing various factors,the variation of the layered segregation rate of coarse aggregate with the same particle size is relatively small.Grading of aggregates has a great influence on the delamination segregation of self-compacting barite concrete.The mass distribution proportion of 16mm～20 mm barite coarse aggregate increases from 10.4% to 14.1%,and the layered segregation rate of concrete mixture increases by 12.28%.(3)Auxiliary vibration can effectively improve the 28 d cube compressive strength of self-compacting barite concrete.The compressive strength of concrete samples without vibration is 36.1 MPa,and the strength range after auxiliary vibration is 35.9 MPa ～ 38.3 MPa.Auxiliary vibration has an impact on the radiation protection performance of self-compacting barite concrete.The greater the concrete segregation,the linear absorption coefficient of three layers in the concrete μ the greater the dispersion of values.Three layers of concrete without vibration μ the standard deviation of the value is1.694%,and it is between 2.31% ～ 4.9% after vibration.(4)The Image-Pro Plus software is used to process the image,the distribution and characteristics of aggregate in concrete section can be presented more intuitively.The variation trend of the layered segregation rate of concrete mixture result calculated by the software with the vibrator voltage and duration is the same as that in the layered segregation test,and this proves that it is feasible to use the software to analyze the segregation of concrete.