The Research On The Key Technology Of High Performance Concrete Based On The Highway Engineering In Guangdong Province

The features of highway engineering concrete are large volume and large surface exposed on the natural environment. It is important for practical engineering to pay more attention on the early performance of cracking resistance and durability of concrete.Fly ash as mineral admixtures is widely used in concrete, but it exists some shortages and cannot satisfy the demands of engineering absolutely to add single mineral admixtures. Studies about the utilization of limestone powder compound mineral admixture concrete, the suitable curing condition and the influence of composition of mineral admixture on the compressive strength and early cracking resistance performance of concrete are a few.In view of above problems, via survey of practical engineering this essay The research on the key technology of high performance concrete based on the highway engineering in Guangdong Province takes the strength and the durability of compound mineral admixture concrete under three different curing conditions as research subjects, at the same time shows the improvement of early cracking resistance in adding compound mineral admixture.The results showed that when the proportion of compound mineral admixture is at the20～50per cent of the total amount of cementing materials, the development of compressive strength of C30and C50concrete meet requirement under the standard curing condition at each age. The quality ratio of limestone powder and fly ash to ground Granulated Blast Furnace Slag powder in the composition of compound mineral admixture is6to4, meanwhile, that of limestone powder to fly ash is7to3in that. For the compound mineral admixture concrete, if it is not carried on wet curing, the compressive strength of concrete declines sharply. Adding to compound mineral admixture is not only having economical efficiency but improving the early performance of cracking resistance and the durability of concrete. With the increase of the amount of mineral admixture, the natural carbonation depth has increased, however, if guaranteed7days of wet curing, the28days carbonation depth of large amount of compound mineral admixture concrete is controlled less than3mm. The chloride ion diffusion coefficient increases with the growth of mineral admixture volume, but it is all in300×10-10cm2/s, so the evaluation of permeability of concrete is at secondary level.