Device and method for monitoring deformation and stress of cement-based material in steaming and maintaining process

Abstract

The invention relates to a device and a method for monitoring deformation and stress of a cement-based material in a steaming and maintaining process and belongs to the technical field of test of civil engineering materials. The device comprises a water bath temperature control heating system, a steel ring restraint system, a swelling deformation test system and a stress test system; the water bath temperature control heating system is composed of a rectangular double-layer heat preservation box and a water temperature control system; the swelling deformation test system is composed of a laserdisplacement sensor and a displacement data acquisition instrument; the laser displacement sensor is fixed on a bracket and directly above a test piece; the internal stress test system is composed ofa strain gauge and a strain data acquisition instrument; the strain gauge is attached to the middle of the outer side of a steel ring; and the strain gauge is connected with the strain acquisition system. According to the device and the method for monitoring deformation and stress of a cement-based material in the steaming and maintaining process in the invention, based on volume deformation characteristic of the steamed concrete in the steaming and maintaining process, the swollen steamed cement-based material is restrained through the external steel ring; the internal stress of the concretein the steaming and maintaining process is obtained through calculation by testing strain of the steel ring; and vertical strain is obtained by testing the change in vertical displacement.

Description

technical field [0001] The invention relates to a device and method for monitoring the deformation and stress of cement-based materials during steam curing, and belongs to the technical field of civil engineering material testing. Background technique [0002] Prefabricated components produced by steam curing technology have been widely used in my country's railway, construction and other industries. The steam curing process is usually divided into four stages, namely, static stop stage, heating stage, constant temperature stage and cooling stage, which has the characteristics of accelerating mold turnover efficiency, improving production efficiency and good economy. At present, the static stop stage is usually set to 3h in the steam culture system adopted. The freshly mixed concrete is still in a plastic state after a 3-hour static stop period, the concrete structure has not been fully established, and the structural strength is very low. Therefore, as the concrete in the...

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Problems solved by technology

However, the annular shrinkage test in the standard uses a steel inner ring to limit the shrinkage of concrete. This standard method is not applicable to cement-based materials that produce volume expansion (such as cement-based materials that will produce volume expansion during the steam curing heating stage).

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