Vibratory Mixing Mechanism And Experimental Study On Improving The Concrete Performance

Concrete is a multiphase, porous non-homogeneous composite materials, From macroto observe, concrete aggregate can be regarded as particles dispersed in the cementcomposition of the body in the two-phase material; From the micro to observe its internalstructure is quite complex, Constituted by aggregate, cement hydration products,unhydrated cement particles, capillary pores, microcrack etc, and the distribution is veryuneven. However, the mechanism of stirring is that make the material collide, convectionand diffusion by stirring. Ultimately achieve the uniformity of macro and micro，at thesame time under the strong physical mixing and chemical changes, the status andperformance of the concrete also has a qualitative change.Through the dual role of agitation and vibration，the vibratory mixing fierce betweenthe material particles collide with each other, Ultimately achieve overall uniformity.Vibration stirring not only reduces the viscosity of concrete between particles, but alsoincreased extrusion and material between the number of collisions, destroy the cementgroup, accelerate the hydration reaction, optimize the pore structure of concrete and holesgraded, reinforce the cement paste-aggregate interface, So improved the properties ofconcrete obviously.On the basis of this theoretical analysis, experimental studies by comparing thedifference in performance with and without vibration mixing. Obtained: For different mixproportion，Vibratory mixing can increase the air content of concrete mixture，reduce theconcrete slump，increase cohesion and water retention, Enhance the strength of concreteand the early age strength is particularly evident.The trial compared the reduce cement content of5%,10%,15%,20%, Under thecondition of the vibrating mixing effect on the performance of concrete. Found that whenreduce the cement content of10%, the strength, workability, and air content of theconcrete meet to design requirements，reduced to15%, only the workability is not satisfied,So that, under conditions of vibration mixing, reducing the cement content is the maininfluence of workability, and the impact on the strength of the second. By adjusting theratio of sand to improve the workability of concrete, and ultimately makes the reduction of15%cement content of the concrete workability, durability and strength are met the designrequirements. To further investigate the effects of vibration mixing from the microscopic aspects,and impact on the micromorphology of reducing the amount of cement. Throughcomparative analysis of the microscopic properties of SEM (scanning electron microscope)and MIP(Mercury intrusion porosimetry), We know that: Vibration mixing compared tono vibration, can significantly improve the interface Micromorphology cement paste andconcrete junction, while improving the pore structure and pore size distribution, enhanceconcrete strength and durability; when on this basis, reducing the cement content of10%,the microscopic properties of concrete is better than no vibration.