Testing method for evaluating working performance of self-compacting concrete

Abstract

The invention relates to a testing method for evaluating working performance of self-compacting concrete. The testing method is characterized in that the testing method comprises the following steps of: 1) preparing an NL-type grouting ability instrument detection device; 2) testing flowing time and time of stopping flowing of the self-compacting concrete in the process that the self-compacting concrete longitudinally flows into a transverse groove; 3) after the self-compacting concrete stops flowing, testing the slump height of the self-compacting concrete and calculating filling rate (FR); and 4) finally taking samples from different positions of the transverse groove, washing coarse aggregates, drying, weighing and calculating segregation rate (SR). The testing method has the characteristic of simply, accurately and comprehensively reflecting the rheological property, the filling property and the homogeneity of the self-compacting concrete, and is particularly suitable for evaluating the working performance of the self-compacting concrete at filling layers of CRTS-III slab tracks.

Description

technical field [0001] The invention relates to the field of concrete, in particular to a test method for evaluating the working performance of self-compacting concrete (SCC). Background technique [0002] Ballastless track has been more and more widely used in high-speed railways at home and abroad. At present, there are two most mature slab ballastless track structures in the world: Japanese Shinkansen slab track (CRTS-I type for short) and German Borg Slab track (referred to as CRTS-II type). my country has a vast territory and great differences in regional characteristics and route conditions. Based on this, my country has developed different ballastless track structures. The ballastless track structure types in my country mainly include CRTS-I type, II type slab type and CRTS-I type, II type double-block track structure. While learning from foreign technologies, it also continues to develop ballastless track structure technology with independent intellectual property ...

AI Technical Summary

Problems solved by technology

[0004] The general-purpose L-type flow meter was originally designed by Japan to evaluate the working performance of underwater self-compacting concrete. The size is 200mm×700mm×150mm (length 700mm, width 200mm, height 150mm), and the volume is 21L. It can be seen that the volume of the vertical groove is smaller than that of the horizontal groove. When all the concrete in the vertical groove flows into the horizontal groove, it is also The horizontal groove cannot be filled fully, and the actual pouring state cannot be properly simulated, and the concrete is only subjected to the friction of the bottom during the flow process, but not the friction force of the upper plate, and the flow state is bottom spreading, which cannot simulate the actual pouring well Condition

[0005] In addition, the transverse groove in the general-purpose L-shaped flow meter is a closed box-shaped body without vent holes; the material used is generally a transparent plexiglass plate or steel plate with a relatively smooth surface, which is different from the friction force received during actual pouring. Larger, it is difficult to truly simulate the force and flow state of self-compacting concrete

And generally only the T of the reaction flow rate can be obtained by testing 700L and H in the case of reaction block 2 / H 1 The two indicators of self-compacting concrete do not take into account the segregation and other inhomogeneity problems caused by self-compacting concrete flowing over a long distance.

Therefore, the general L-type flow meter cannot fully and accurately reflect the performance of self-compacting concrete.

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