Device and method for measuring early age period linear deformation of cement based material

Abstract

The invention discloses a measurement device and a measurement method of early-age linear deformation of cement-based materials; the measurement device comprises: a measurement containing cavity which is provided with an opening at the upper end and composed of a bottom board, a side board and an outer end board, wherein, a sliding template is further arranged on the bottom board, inner end boards are arranged at the both ends of the template, and a separation groove is arranged in the middle of the template for dividing the template into two sliding templates. Compared with the prior art, the sliding template is arranged on the bottom board of the measurement device of the invention, the template is divided into two by the separation groove, when a cement-based material sample is deformed, the displacement thereof can be measured by the sliding template which is bonded with the cement-based materials, the properties of the early-age linear deformation of the cement-based materials can be accurately reflected without the need of waiting for hardening of the cement-based materials. Sliding slots are respectively arranged on the bottom board and the template, rolling balls are arranged in the sliding slots, thereby changing sliding friction into rolling friction, greatly reducing the friction and improving the measurement precision.

Description

technical field [0001] The invention relates to a measuring device and method for linear deformation of cement-based materials at an early age, which can be used to form cement-based materials such as cement paste, mortar, concrete, and solid materials such as aggregates under unconstrained conditions. Mold and measure. Under different heating systems and curing systems, it can measure the thermal expansion coefficient, self-shrinkage and drying shrinkage of cement-based materials in the early stage. Background technique [0002] In the field of civil engineering, early age cracking prediction of concrete structures is very important. At the early age of the concrete structure, the thermodynamic properties of the concrete material are extremely unstable, and various thermodynamic properties of the early-age concrete directly determine the cracking evaluation of the early-age concrete. Accurately measure various thermodynamic properties of the early-age concrete The law of ...

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Problems solved by technology

Chinese patent No. 200510012299.3 discloses an automatic measurement system for concrete temperature linear deformation, and proposes an automatic method for measuring the linear expansion coefficient of concrete, but its mold is not suitable for the measurement of early-age cement-based materials

Chinese Patent No. 200610038892.X discloses a method and device for testing the early self-deformation of concrete, which can make the initial time of self-shrinkage measurement earlier after pouring, but it is not suitable for early-age concrete because there is no temperature control system Determination of thermal expansion coefficient

[0007] The thermal performance of the test platform material is often ignored, but it greatly affects the results of the test measurement, causing large errors

[0008] The guide rods used for deformation measurement are mostly copper alloy guide rods, and the thermal expansion coefficient of copper alloy is 16.6-17.6×10 -6 / °C, not suitable for tests with large changes in ambient temperature, and it is very inconvenient to install and disassemble with steel molds

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