Study On Properties Of Functional Concrete

Electrically conductive concrete is an important part of intelligent concrete, the studies on the performance and application of it has been more attention. This paper is mainly to study the volume and types of conductive materials for the performance and regularity of concrete work, mechanical and electrical properties. Conductive material is mainly used in the test of nandmeter carbon black, steel and carbon fiber, which is a new type of nano-Nano carbon black conductive materials, study of its impact on the performance of conductive concrete is tery meaningful.Firstly, according to test raw material characteristics and requirements of electrically conduc concrete, through the design and test, determine the C40concrete mixture ratio and the production proc of electrically conductive concrete. Study on conductive materials on the effect of expansion of slump electrically conductive concrete. Tests show that, expansion of concrete slump increase with incorporation of conductive materials becomes small, effect of nanometer carbon black on the workability the concrete is the largest, adding quality content0.4%of nanometer carbon black conductive concrete become thick, porous and poorly cohesive. Small amounts of carbon fiber and steel fiber add to concrete, workability of concrete is good. The losses of expansion of concrete slump with mixed conductive mater: than the losses of expansion of concrete slump with single conductive materials are bigger, the losses expansion of concrete slump with mixed carbon fiber and nanometer carbon black than the losses expansion of concrete slump with mixed carbon fiber and steel fiber are bigger.Secondly, studies on conductive materials on the conductive effect of compressive strength of concrete and flexural strength. Experimental results show that:the compressive strength of the concrete added small dosage of nanometer carbon black increases as with the amount of nanometer carbon black, especially on improving effect of compressive strength of concrete at early age clearly. The results of the compressive strength of the control group and singly added carbon fiber or steel fiber concrete are almost. Flexural strength of concrete with nanometerJ carbon gradually decreased as with nanometer-carbon black adding, the loss rate of flexural strength of concrete added quality content is0.4%of nanometer-carbon black is26.3%. The impact trend of flexural strength of concrete added singly carbon or steel fiber are firstly increasing then decreasing.Finally, the study on the conductivity of electrically conductive concrete is mainly about different factors effect on resistivity of conductive concrete numerical size and stability. The test of resistance of the conductive concrete is mainly used four electrode method, and two-electrode method was compared. According to test data, early in the concrete hydration, different kinds and contents of conductive materials have little effect on electrical resistivity of electrically conductive concrete. Hydration-age growth, nanometer carbon black on the lower resistivity of conductive concrete is not obvious, but the stability of electrical resistivity of concrete mixed with carbon black is better than carbon fiber-reinforced concrete or steel-fiber concrete. When the amount of carbon fibers mixed greatly, the resistivity of electrically conductive concrete is lower, and the percolation threshold is obvious. When the quality of steel fiber content12%(50kg/m5), Numerical resistivity of steel fiber reinforced concrete is very small, but with age the growth trend is very clear, resistivity instability. When the same volume, carbon-reducing effect on resistivity of concrete is better than nanometer carbon black or mixed both carbon fiber and carbon black effects. When using four-electrode method and two electrode method for measuring resistivity, with two-electrode method for measuring resistivity is larger, especially in the early hydration, two electrodes method for measuring electrical resistivity is larger. However, with the increase in hydration age, the difference of two methods for measuring electrical resistivity decreases, When carbon fiber concrete mixed with large amount of carbon, the difference resistivity is smaller. Voltages of different sizes will have an impact on test results. At low voltage, the measured resistivity of the concrete will be relatively large. When the longer hydration age, the difference on resistivity of concrete measured at high and low voltage is greater.