Research On The High-performance Concrete Mineral Admixture And Performance

The concrete is an indispensable part of modern civil engineering, the largest amount, the most widely used materials.However ordinary concrete is not as expected so safety.Phenomenon of structural damage caused by insufficient durability in the growing.High performance concrete with high strength,good workability,excellent durability and other technical target for the design goal. At around the world in recent years it has been widely used in a variety of building structures.At the same time,how to improve and assess the permeability of high performance concrete has become an urgent task for research.In this paper, the fly ash and slag powder from Xinjiang region were used as admixture in the concrete, and test different types of activity admixture to stimulate the mineral in the cement mortar, while application of different types and dosage water-reducer agent to test the changes of cement mortar. By orthogonal experiment testing and analysis of the strength performance changes of the cement mortar and concrete, when the fly ash content of20%,25%and30%, the slag powder content of30%,40%and50%, water-reducing agent content of0.1%to1.5%. Select the appropriate groups test the physical properties of concrete in7d and28d. Through XRD and the SEM microscopic test method, the microstructure and hydration mechanism of cement mortar test block and concrete has studied.Through the test, the optimal content of fly ash is25-30%, the appropriate content of slag powder is30%, the appropriate content of polycarboxylate superpl-asticizer is0.3-0.8%, and the appropriate content of the laboratory-made activator is1%under the standard curing and natural curing conditions when the w/c ratio is0.41. Conditions of this test, the cement and concrete of the performance indicators can be prepared as high-performance concrete, long-term mechanical proper-ties of concrete at this time, the concrete also of high early strength, high toughness and volume stability; It can be maintain a longer life under adverse conditions.Through XRD and the SEM microscopic test method, the result indicated that the initial hydration products are Ca(OH)2and a small amount of ettringite, the late main hydration products are large amount of ettringite and C-S-H gel, The crystallization state of hydrated product are good, the active ingredient in mineral admixture participate hydration reaction, to form a high-per-formance concrete structural system.Use the fly ash and slag powder preparation of concrete from Xinjiang region, while adding high-performance water-reducing agent and the activity of activator can improve concrete performance indicators, to produce high-performance green concrete. If it can be applied into the industrial production, it will not only benefit from the utilization of solid waste disposals, but also has significant economic and social benefits.