The Preparation And Performances Investigation Of Compound Conductive Aggregate And Its Cement-based Composites

The conductive concrete is an important development direction of the concrete, due to its electrical performance, pressure-sensitive, conductive concrete is suitable for building heating, snow melting and the automatic monitoring of weight and car flow in the highway. Besides, conductive concrete is one way of intelligentize the civil engineering structure and operational safety monitoring. Study the composition and structure of the conductive concrete; enhance its performance has important academic value and practical significance.This article rely on the National Natural Science Foundation projects, in the traditional conductive concrete, the aggregate are non-conductive, which influence integrity, uniformity and stability of the conductive network. Start the research of the preparation and performances investigation of compound conductive aggregate and its cement-based composites. The main results are as follows:Advance the preparation method of conductive function aggregate with different conductive phase, use clay as matrix material, use carbon powder、carbon fiber powder、carbon nano tube and nano carbon black as conductive phase respect. Through test the performance of the conductive function aggregate that prepared in different conductive phase, content and calcinations conditions, determine the preparation technology of conductive function aggregate, prepare the conductive function aggregate whose conductive performance and strength performance is in balance.The influence of the size and morphology of the conductive phase to aggregate is verified. Use four kinds conductive phase with different size and morphology to prepare conductive aggregates, though test its mechanical properties, electrical properties, combined with the microscopic test that observe the distribution of electrical conductivity in the conductive aggregates, determine the suitable size and morphology of conductive phase to prepare conductive aggregate. Obtain the percolation range of different conductivity for prepare conductive aggregates.The influence that conductive aggregate with different resistivity have on the conductive network of carbon fibers and conductive concrete’s varistor properties is researched. Use three kinds conductive aggregate of different resistivity to prepare conductive concrete as aggregate, use the four-electrode method to test electrical properties of the conductive concrete, use one-way uniform load to test conductive concrete’s varistor properties, the experimental results show that conductive aggregate with different resistivity influence the conductive differently, when the aggregate’s resistivity number is level102, the conductive concrete has good electrical properties. When the aggregate’s resistivity number is level103, the conductive concrete has good varistor properties.