Research On Fly Ash Activity Excitation And Mechanical Performance Of High Fly Ash Content Concrete

As a kind of industrial by-product, the emission of fly ash is so great in China, but its utiliziationis is low and it increases environmental load. High fly ash content concrete as a "green" building materials can consume plenty of fly ash, not only reduce cement dosages and the production of concrete, reduce environmental pollution and save the cultivated land, but also play a greater degree of performance advantages, improving working performance, durability and physical and mechanical properties of concrete.Using fly ash to replace cement in concrete makes the early strength low, and it is more obvious in high fly ash concent concrete. It is the main reason that the potential activity of fly ash has not been fully excitation, which limits the application scope of high fly ash content concrete.It is not difficult to find the main insufficient to stimulate the activity of fly ash through analysising domestic and foreign research status of fly ash activity excitation. Such as:(1)The studies on effect comparison and mechanism of activator monomers simulating the activities of cementitious materials with different amount of fly ash are relatively seldom.(2)The studies on effect comparison and mechanism of two kinds of activators compound simulating the activities of cementitious materials with different amount of fly ash are relatively seldom.This paper tends to study the influence of fly ash excitation to the mechanical performance of high fly ash content concrete. With exploration of active excitation mechanism of fly ash, this paper mixed the fly ash with several exciting agent system by single or double ways, to find a more appropriate excitation agent with high volume of fly-ash and get its best activity. What’s more, this paper try to find the real relationship between the three factors (water-binder ratio, fly ash excitation agent dosage) and compressive strength and elastic modulus of concrete with high volume of fly-ash on 7d,28d and 90d by nonparametric regression analysis. To sum, this paper devotes to solve the problem that concrete early strength problem is too low with a large number of fly ash as active mixing material, find out the suitable dosage of fly ash and the optimal excitation agent dosage, and provides a theoretical and experimental basis for the promotion and application of high fly ash content concrete.