Fly Ash Concrete Frost Resistance Prediction

Durability of concrete is concrete is the most important properties for fly ash concrete is also moreand more, with the promotion of fly ash concrete, which fly ash concrete frost resistance is a veryimportant part of, and accumulated a lot of valuable research results and practical experience. Informationfor the rich fly ash concrete frost resistance of theoretical research and engineering design, constructionrequirements, fly ash concrete frost forecasting software is essential. From the relative dynamic elasticmodulus of fly ash concrete freeze-thaw cycle after starting to explore the pros and cons of the evaluationof frost resistance of fly ash concrete frost forecasting model by the method of mathematical modeling,led to the development the fly ash concrete frost resistance prediction software. The main content of thispaper is as follows:(1) fly ash concrete frost resistance Research, analyze the advantages and disadvantages of the variousfreeze-thaw damage mechanism, look at the freeze-thaw cycle to the point of view of freeze-thaw damageand failure phenomena.(2) combined with the pre fly ash concrete frost resistance test research, by analyzing the single factorunder the conditions of the dynamic elastic modulus after the freeze-thaw cycles and relative dynamicmodulus of elasticity trends, that the gas content, water binder ratio and fly ash fly ash concrete frostresistance have a significant impact. With the increase of water-cement ratio, concrete, dynamic elasticmodulus decreases, the relative dynamic elastic modulus decreased faster; gas content increases with theincrease of air entraining agent dosage, ie, concrete, dynamic elastic modulus and trend of declineaccelerated relative dynamic modulus of elasticity of the rate of decline slows; with the fly ash contentincreases, the relative dynamic elastic modulus, dynamic modulus of elasticity was first decreases, thenincreases, and also reduces determine the water-cement ratio and air content, the optimum content of flyash. Increase in gas content to slow down the degradation rate of fly ash concrete frost resistance,water-cement ratio and the increase in fly ash accelerated the deterioration speed of the fly ash concretefrost resistance.(3) The current evaluation of concrete frost resistance merits of the standard is the antifreeze level, theseantifreeze levels are discrete points, with a freezing level of two sets of concrete, can not compare themerits of its frost resistance, and the discrete points is not conducive to the prediction model. Relative dynamic elastic modulus of fly ash concrete freeze-thaw cycle after starting the use of phenomenologicaldamage mechanics to determine the damage degree D defined expression, the use of the continuity of thedamage degree of frost durability of fly ash concrete The index DF and freeze-thaw cycles organicallycombine the reference to other empirical models, to establish the basic structure of the mathematicalrelationship between the expression of frost durability index of concrete frost resistance. By1stoptsoftware for multivariate nonlinear regression analysis, fly ash concrete frost resistance predictivemathematical model.(4) the use of Visual Basic6.0language programming, the development of the fly ash concrete frostforecasting software, and engineering example, the fact that the software is simple, strong adaptability andreliability to meet the practical engineering needs.