Pervious concrete aggregate particle size measurement method based on image processing

Abstract

The invention discloses a pervious concrete aggregate particle size measurement method based on image processing. The method comprises the steps that a set quantity of pervious concrete aggregates are selected to be placed on white paper, a ruler with scales is placed, a square area is shot, and a digital photo is obtained; the digital photo is processed, and conversion of a pixel value and a millimeter distance value is completed; blackening and whitening processing is conducted; the particle size area of each particle is output, each aggregate particle is assumed as a circle, and the particle size is calculated; the particle sizes of all the aggregate particles in different shooting angles are averaged, and the initial particle size di0 of the i aggregate particle of pervious concrete is obtained; the aggregate volume expansion rate caused by a hydration product is calculated, the aggregate diameter enlarging rate is calculated through the aggregate volume expansion rate, the aggregate equivalent particle size is calculated through the aggregate diameter enlarging rate, correction on the initial particle size di0 of the i aggregate particle of the pervious concrete is completed, and the equivalent particle size Di of the i aggregate particle is obtained. The method has the advantages that operation is easy, processing is convenient, and a final result is stable and reliable.

Description

technical field [0001] The invention relates to a method for measuring the particle size of permeable concrete aggregates based on image processing. Background technique [0002] Compared with ordinary concrete, pervious concrete has excellent performances such as air permeability, water permeability, sound absorption and noise reduction, water purification, improvement of surface soil ecological environment, mitigation of surface runoff and urban heat island effect. Therefore, under the guidance of ideas such as sustainable development and maintenance of ecological balance, some developed countries such as Europe, America, Japan and South Korea began to study and apply permeable concrete more than 50 years ago. In recent years, domestic research and application of pervious concrete have become more and more extensive. Permeable concrete, also known as porous concrete, is composed of coarse aggregate, water and cement. Coarse aggregate is used as the skeleton. The particle ...

AI Technical Summary

Problems solved by technology

The traditional sieving method has poor measurement accuracy and heavy workload, and because the national standard specification "Building Sand" (GB / T14684-2011) stipulates that the sieving aperture size includes 0.15, 0.3, 0.6, 1.18, 2.36, 4.75 and 9.5mm, there is no pore diameter between 4.75 and 9.5mm, and limestone gravel of 4.75-9.5mm is commonly used in pervious concrete specimen tests, and the aggregate-plugging material size ratio cannot be obtained only through sieving tests, so it is impossible conduct further research

[0004] The existing technology often does not consider the aggregate volume expansion rate caused by hydration products, resulting in inaccurate measurement results

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