Limestone micro powder-steel slag powder-slag powder composite admixture and preparation process thereof

Abstract

The invention provides a limestone micro powder-steel slag powder-slag powder composite admixture and a preparation process thereof. The composite admixture comprises 10-30% of limestone micro powder,20-50% of steel slag powder, and 30-60% of slag powder according to a weight ratio. The preparation method comprises the following steps: drying, crushing, grinding, grading or sieving limestone andsteel slag respectively to obtain limestone micro powder and steel slag powder; and then uniformly mixing the limestone micro powder, the steel slag powder and the slag powder according to proportionsto obtain a limestone micro powder-steel slag powder-slag powder composite admixture, wherein the slag powder performance meets an S95 level technical requirement in GB / T18046-2017 'Granulated blastfurnace slag powder for cement, mortar and concrete'. According to the invention, high-activity S95-grade slag powder is selected, and through mutual excitation of limestone micro powder, steel slag powder and slag powder, a micro-aggregate effect is generated, so that the compatibility of the admixture with cement and a water reducing agent is improved, the dry shrinkage rate of cement mortar isreduced, and the concrete strength is improved.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a limestone micropowder-steel slag powder-slag powder composite admixture and a preparation process thereof. Background technique [0002] Protecting the environment, reducing the consumption of natural resources and improving the performance of cement concrete are the two most important issues facing the field of cement and concrete. The application of concrete admixtures, on the one hand, can effectively control the total production of Portland cement, so that the existing industrial waste can be recycled and reused, thereby reducing the load on resources and the environment of the building materials industry itself and other industrial industries; on the other hand On the one hand, concrete admixtures can significantly improve the mechanical properties, work properties, corrosion resistance and durability of concrete, and are an indispensable structural ...

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Problems solved by technology

At present, there has been research on mixing steel slag powder, slag powder and limestone powder to prepare concrete admixtures. For example, the patent application with application number 201611132042.6 discloses that 1-5 parts of hot-smelling furnace brick steel slag powder and 4-10 parts of granulated Blast furnace slag powder and 0-1.6 parts of limestone powder are mixed to obtain concrete mineral admixture, but the raw material used in this concrete mineral admixture has a large particle size and low activity, and the concrete prepared by using it has poor compressive strength, and the 7d compressive strength The strength is only 25.1-30.3MPa, and the 28d compressive strength is only 44.6-50.2MPa, which is far from meeting the demand

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