Study On Road Performance Of Nano-Cement Concrete

Because of its small size, nanometer materials have special physical,chemical and structure characteristics. Nanometer materials have become the focus of material researching field today. Mixing with adequate nano-SiO2 can improve mechanical properties and durability of cement concrete, make concrete road have a better service performance and longer service life.Through the investigating application status of cement concrete mixing with nano-SiO2, this paper analyzed systematically the reinforced mechanism of nano-cement concrete, cement concrete compressive flexural strength, fracture toughness, fatigue life and shrinkage properties were studied, proposed nano-cement concrete pavement construction process and technology controlling measures.This paper analyzed systematically reinforcement mechanism of nano-cement concrete, studies have shown that nano-SiO2 reinforcing mechanism produced by means of cement hydration, the reaction with Ca(OH)2 of cement local paste and ITZ and the improvement of concrete pore structure; compared with ordinary concrete, early compressive strength of nano-cement concrete improved obviously, but the late strength had no significant change; if the content of nano-SiO2 is 0.5%,0.75%,1.0%,1.5%, the bending strength increased by 2.9%, 7.4%,3.7%,3.2%, the increase is most prominent at the content 0.75%; compared with ordinary concrete, the ability to resist deformation of nano-cement concrete were significantly increased, at the load 40KN, deformation of nano-cement concrete increased by about 25% than common concrete; compared to common concrete, fracture toughness of nano-concrete increased by 19.5-39.3%, the fracture energy corresponding increased by 2.5-2.9 times; at high stress level, the fatigue life of nano-cement concrete improved significantly compared to common cement concrete; under the stress level 0.75,0.80 and 0.85, the fatigue life is respectively improved by 48.4%,58.6% and 68.6%; the shrinkage of nano-cement concrete is more obvious than common cement concrete, it increased by 66.8%-198.7% in the test, and early shrinkage is more notable.Through the above mechanism analysis and experimental study, a nano-cement concrete Test Section were completed, road pavement technology and construction control measures of nano-cement concrete were proposed.