T/JSJTQX 14-2020 Active Group standards

T/JSJTQX 14-2020 Recycling coarse aggregate used in concrete mixture

Publish Date: 2020-12-27 Implement Date: 2021-01-01 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

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Basic Information

Standard Code: T/JSJTQX 14-2020

Standard Type: Group standards

Standard Status: Active

is_force_gb: no

CCS Name: Concrete, aggregates, mortar, and grout

ICS Name: Concrete and concrete products

Publish Date: 2020-12-27

Implement Date: 2021-01-01

Scope

Scope: This document specifies the classification and specifications, technical requirements, test methods, inspection rules, marking, storage and transportation, and application requirements of mixed recycled coarse aggregates. This document is applicable to mixed recycled coarse aggregates used in the construction of cement concrete road pavements, industrial and civil buildings, and general structures; Main technical content: The technical content of this standard mainly includes two aspects: the selection of main grading indicators and the determination of grading ranges for mixed recycled coarse aggregates. Through experiments, the physical and mechanical properties of a group of ordinary coarse aggregates and twenty-three groups of mixed recycled coarse aggregates, as well as the concrete cast from each group of coarse aggregates, were tested. Based on the weight-slope-gray correlation degree analysis method, the correlation between the aggregate performance and the concrete performance was calculated. The correlation between the aggregate water absorption, crushing index, saturated surface dry density, and apparent density and the concrete mechanical properties were 0.502, 0.647, 0.179, and 0.283, respectively; thus, the aggregate water absorption and crushing index were selected as the main grading indicators for evaluating mixed recycled aggregates. On the basis of GB/T 25177-2010, the grading ranges of the main grading indicators were redefined. The principle of defining the grading ranges is as follows: if the mechanical properties of the mixed recycled concrete meet those of ordinary aggregate concrete, the corresponding mixed recycled coarse aggregates will be classified as Class I; if the mechanical properties of the recycled concrete do not meet those of ordinary aggregate concrete, the corresponding mixed recycled coarse aggregates will be classified as Class II. It is recommended that Class I mixed recycled coarse aggregates can be used to prepare c