Method and device for detecting shrinkage and cracking performance of cement-based material

Abstract

The invention provides a method and a system for detecting shrinkage and cracking performance of a cement-based material based on image processing technology, and belongs to the field of material detection. The system mainly comprises an image acquisition unit, an image processing unit, a result display unit, a communication unit and the like; the image processing unit comprises an image pre-processing unit, an image enhancing unit and an image analyzing unit, wherein the image pre-processing unit finishes gray conversion of images and selection and shear of an effective area; the image enhancing unit peels a research object and a background image through smoothing, sharpening and gray morphology operation in turn; and the image analyzing unit finishes characteristic extraction of the research object and calculation of the crack width and shrinkage value. The detection method of the invention has the advantages of low computation and high image resolution; and the system has the advantages of stable structure, visual analysis, multiple channels, high precision (20 mum) and good economy, and is applicable to global detection and evaluation for the shrinkage and cracking performance development process of materials such as neat slurry, mortar, concrete and the like.

Description

technical field [0001] The invention relates to the field of material detection, in particular to a method and a device for detecting shrinkage and cracking properties of cement-based materials. Background technique [0002] In cement production technology and concrete preparation technology, the shrinkage and cracking of cement-based materials will seriously affect the volume stability and durability of materials, which is also a hot research topic for domestic and foreign scholars. Although there are many related test methods, such as the use of contact methods based on length and volume changes, and non-contact methods based on sensors and optical principles to measure shrinkage properties, the existing test methods have their own advantages and disadvantages: the contact method has simple equipment , but the accuracy is low and is easily affected by the subjective factors of the operator; the non-contact method has advantages in accuracy, but there are problems such as c...

AI Technical Summary

Problems solved by technology

Although there are many related test methods, such as the use of contact methods based on length and volume changes, and non-contact methods based on sensors and optical principles to measure shrinkage performance, the existing test methods have their own advantages and disadvantages: the contact method has simple equipment , but the accuracy is low and is easily affected by the subjective factors of the operator; the non-contact method has advantages in accuracy, but there are problems such as the actual operation process is more complicated and the cost is high, and both methods are only suitable for the measurement of shrinkage at different stages

[0003] Geng Fei used the Delphi language to write the "crack image analysis software" to observe and evaluate the characteristics of concrete plastic cracks (Master's thesis of Southeast University). Large defects (due to the limitation of imaging tools, the image resolution is 640×480Pixels, the actual accuracy is millimeter level), if used for shrinkage measurement, its accuracy is far from enough

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