Method and device for measuring volume deformation of concrete or mortar

Abstract

The invention discloses a method and device for measuring the volume deformation of concrete or mortar. The mixture of concrete or mortar prepared according to engineering requirements is poured into an open test mold box, and then the concrete or mortar is filled with Put the open-top test mold box of the mortar mixture into the heat-insulating thermos bottle as a whole, and then seal the mouth of the heat-insulating thermos bottle with a sealing cap with a scale tube, an air guide tube and a thermometer, and pass the scale tube to the heat-insulating Pour a liquid that does not dissolve with water into the thermos bottle, so that the liquid will completely submerge the test mold box and fill the inner cavity of the thermal insulation thermos bottle, and then put the entire thermal insulation thermos bottle into the constant temperature water area, so that it can pass through the liquid surface in the scale tube. It can accurately measure the volume expansion or contraction deformation of concrete or mortar under adiabatic conditions. The invention not only has the advantages of high measurement accuracy, but also has the advantages of simple structure, convenient operation and the like.

Description

technical field [0001] The invention relates to a method and a device for measuring volume deformation of concrete or mortar, and belongs to the technical field of concrete deformation measurement. Background technique [0002] At present, with the rapid development of domestic economic construction, a large number of civil engineering projects have sprung up, and high-strength high-performance concrete and self-compacting concrete have been widely used. At the same time, the construction unit encountered many early cracking problems in concrete. For example, when the basement shear wall concrete was poured and the formwork was removed, regular penetrating cracks appeared. This phenomenon is especially obvious in high-strength concrete and self-compacting concrete. According to the shrinkage test in the current national standard "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete" GBT50082-2009, the method of long-term shrinkage is to plac...

AI Technical Summary

Problems solved by technology

Although this method can reflect the volume change of concrete more comprehensively, because the tested concrete is packed in a sealed sample bag, the water temperature change of the concrete and the corresponding change of its volume cannot be measured, and This measurement method reflects the volume change of the concrete through the change of the volume of the sample bag, because the sample bag and concrete are two different materials, and their volume changes are different at the same temperature. The difference in volume change will directly affect the measurement accuracy, and the volume of concrete will be constrained by the sample bag when it changes, and this constraint will affect the natural change of concrete; and after the concrete is loaded into the sample bag, it will When sealing the sample bag, it is difficult to ensure that there is no certain space between the concrete and the inner cavity of the sample bag, and the existence of this space will also affect the measurement accuracy

Therefore, this method not only has the problem of troublesome operation, but also its measurement accuracy is not ideal.

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