Apparatus and method for applying permanent axial tensile load to multiple concrete specimens

Abstract

The present invention provides a test device for applying permanent axial load to multiple concrete specimens. The test device includes: at least three reaction frames, an upper beam, a load distribution beam, a plurality of serial connecting rods, at least Two threaded connecting rods, four limit fasteners, a gear jack, and a pressure sensor; the threaded connecting rods pass through the upper beam and are fixed by nuts; the threaded connecting rods hang multiple concrete specimens to form a concrete For the test piece string, the load distribution beam is erected horizontally under the lower beams of the three reaction frames, the limit fasteners are welded to both ends of the load distribution beam, and the bottom of the lower beam of the reaction frame in the middle is connected to the load distribution beam. The gear jack is set, and the pressure sensor is set on the gear jack. The invention can apply persistent axial load to multiple concrete test pieces at the same time, reducing the workload of the test; the positioning of the embedded parts is accurate, which can improve the precision of the test; and it can be quickly dismantled and used in turnaround.

Description

technical field [0001] The invention relates to the technical field of construction, in particular to a test device and method for applying a persistent axial tensile damage load to a plurality of early-age concrete specimens. Background technique [0002] Early demolition formwork technology is a new type of "quick dismantling system", which is in the stage of project promotion and application. The "quick release system" means that when the concrete poured in a certain layer reaches a certain strength, under the premise of ensuring construction safety, except for the reserved vertical poles and late removal support heads, the beam bottom formwork is removed early, thereby speeding up the construction progress . At present, the demolition time of the beam and slab bottom formwork in the aluminum alloy early demolition formwork technology is mainly based on foreign experience, and the beam and slab bottom formwork will be removed when the concrete age reaches 36 hours. Howe...

AI Technical Summary

Problems solved by technology

[0016] ①The variable cross-section method is cumbersome to manufacture the test piece, and corresponding templates need to be made, which leads to large errors in the geometric dimensions of the test piece, which in turn leads to eccentric force

[0017] ②The installation of embedded parts is time-consuming and labor-intensive

The pre-embedded steel bars require accurate embedding, and it is troublesome whether it is preparation work, making test pieces or connecting bolts before the test; the bonding law requires the bonding surface of the test piece to be carefully handled, and the hardening of the adhesive also takes a certain amount of time. It is not applicable to the damage of early-age concrete specimens and the test of elastic modulus after damage

[0018] ③ Only a single concrete specimen can be tested, and the test workload is heavy

[0019] ④Cannot apply permanent axial load to the concrete specimen

Most of the current tests of applying axial tension to concrete specimens are one-time destructive tests.

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