A design method of mix proportion of self-compacting concrete mixture

Abstract

The invention belongs to the technical field of concrete construction, and in particular relates to a method for designing the mixing ratio of self-compacting concrete mixture. The method includes: determining the performance design target, determining the preparation strength and water-binder ratio, determining the densest gradation (or sand rate) of the aggregate and the void ratio of different packing states, determining the amount of cementitious material and mixing water, determining the amount of bone Steps such as determining the amount of materials used, determining the amount of admixtures, and determining the actual amount of mixing water added. The present invention aims at the blindness of material selection in the design of self-compacting concrete mix ratio in the prior art, based on the basic theory of dense accumulation of particles and the composition law of solid particle materials with different particle sizes reaching the most densely packed state, the measured most densely packed state Determine the mix ratio of different materials, and at the same time establish a relationship between the mix ratio of materials corresponding to different close-packed states and the expected self-compacting performance level of the mixture, and build a set of self-compacting high-performance concrete mixtures based on the use performance as the goal. than the design method.

Description

technical field [0001] The invention belongs to the technical field of concrete construction and relates to a method for designing the mixing ratio of self-compacting concrete mixture. Background technique [0002] Self-compacting concrete is a new type of high-performance concrete that has high fluidity at low water-binder ratio without segregation and bleeding, and ensures that it can fill the mold cavity and wrap steel bars by itself without vibration under unfavorable pouring conditions. Due to the use of a large amount of industrial waste mineral fine admixtures, self-compacting concrete can significantly reduce the temperature rise of concrete, thereby improving the ability to resist external environmental erosion and deterioration, thereby improving the durability of the concrete structure; at the same time, the use of mineral fine admixtures saves cement, Reduced carbon emissions and energy consumption in cement production. Due to the above advantages, self-compacti...

AI Technical Summary

Problems solved by technology

Although the packing theory has been researched and applied in the concrete industry for many years, so far, there is no set of practical methods for determining the mix ratio of self-compacting high-performance concrete based on the theory, let alone the material of the mix. The composition is directly related to the self-compacting performance level. For example, the Chinese patent (application publication number CN 103304206 A) discloses a super-high-strength self-compacting concrete and its preparation method, which mainly consists of cementitious materials, high-efficiency water reducing agents, fine aggregates, Composed of coarse aggregate, water and PVA fiber, the mass percentages of cement, slag and silica fume that make up the cementitious material are: cement 70%-80%, slag 10%-20%, silica fume 5%-10%

Although the invention mentions the optimal design of ultra-high-strength self-compacting concrete based on the closest packing theory, the application documents do not involve information on any method for determining the amount of various materials using the closest packing theory. It is still the traditional concrete mix design method and mode, and the performance of the designed mixture is unpredictable, and it must be tested and adjusted in the later stage

[0005] Generally speaking, the blindness of the existing technology in the design of material mix ratio not only increases the workload of trial adjustment, but also brings waste of resources. Therefore, it is necessary to explore a more practical self-compacting high-performance concrete A New Method of Designing Mixture Ratio

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