Experimental Research On The Performance Of Concrete Permeability Effect Using Nano Materials And Fly Ash Together

Concrete permeability is one of the most important indicators of concrete durability. Degradation speed of great penetration-proof concrete is very slow. Mineral admixtures as components of concrete can improve the durability of concrete, nano materials and fly ash were used together in concret can bring their own advantages, to the durability of concrete as a"complementary"effect. Based on the research of nano materials mixing fly ash concrete permeability is the basic point of departure in this paper.According to above mentioned basic starting point, work performance, mechanical properties, carbonation of only mixed nano materials or only mixed fly ash mortar were tsted at the first, so as to determine fixed the best mix design and proportion of concrete permeability research. The results of congcrete permeability were evaluated through methods 6h DC quantity and NEL, under the same conditions of proportion and admixture quantity the research of concrete anti-freeze capability was studied, the preliminary explanation of the relationship between permeability and anti-carbonization (anti-freezed) were made.The results show: the reduce of W/B can improve the compressive strength of concrete, nano materials can reduce work performanceof the concrete, improve the early strength, the compactness penetration-proof quality and anti-carbonation ability of the concrete. And fly ash can improve the performance of concrete, besides the increase of fly ash can reduce the early strength and anti-carbonation ability. The workability, mechanical properties, anti-carbonation ability and anti-permeability can toward positive way when nano materials and fly ash were used together, which embodies the "complementary" effect.After mixing fly ash and nano materials on concrete anti-carbonation ability and anti-permeability has stimulative effect, to a certain extent, the rusult illustrates anti-permeability is helpful of anti-carbonization ability. However the great anti-permeability nano materials concrete shows the"brittle"of the anti-freeze after 300 times freezethawing cycle, without any sign the cracks will occur from the department or middle of the specimens, the result is not improved after incorporating a certain amount of fly ash, showing difference of the concrete permeability, the reason of this situation because the nano material has high surface activity and hydration reaction fast, led to the later energy reserves is insufficient, the mechanism and reason needs to be further studied and discussed. This paper firstly put forward the concept of anti-freeze"fragile", the main reason might be because nano materials have high activity and hydration reaction fast, its own storage capacity is consumed prematurely, later energy reserves were not enough, under the action of freezethawing cycle low energy reserves had not hold up the original high performance system, concrete"brittle"failure was happped naturly without any sign.