JP2000009722A - Surface water ratio automatic continuous measurement device for sand attached to ready-mixed concrete production plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for accurately measuring the surface water radio of sands used for mixing concrete. SOLUTION: A black paper is piled on the back of a while filter paper to thereby make a sheet of composite paper 5. When surface water of sands is forcibly absorbed by the composite paper 5, a water-absorbing part of the white filter paper floats up the black color of the black paper on the back thereof. The expanded state of the floated black color is photographed by a digital camera 10, and the photographed information fetched into a computer 11, and a surface water ratio the sands is obtained from the relation between a surface water ratio obtained before hand and an area of the black color which floated up on the surface of the white filter paper due to the absorption of the surface water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The true surface of sand per batch of ready-mixed concrete is measured by measuring the surface water content of the sand used in the ready-mixed concrete production plant instantaneously, continuously and accurately. The water content can be measured. This makes it possible to accurately correct the mixing water amount of the concrete, and to prevent the slump and strength of the concrete that has been mixed from reaching the target values.

[0002]

2. Description of the Related Art In the prior art, since the surface water content of a sand used for concrete kneading cannot be directly measured immediately before the measurement, sand is taken out of a sand storage bin of a plant in advance. Was dried or its specific gravity was measured to determine the surface water content. However, this method requires a long time to produce the measurement result, and cannot measure the true surface water content of the sand to be measured. For this reason, it is different from the true value of the surface water content of the sand immediately before the measurement. At present, the slump and strength of the kneaded concrete are far from their target values in order to correct the mixing water with this value.

[0003]

An accurate correction of the mixing water amount for each batch of ready-mixed concrete by directly measuring the true value of the surface water content of sand instantaneously and continuously. The slump and strength of the concrete can be set to its target value.

[0004]

A composite paper is made by laying black paper on the back of a white paper. Surface water in the sand is forcibly absorbed by the composite paper. The water-absorbed white paper passes through the light, causing the black color of the black paper behind it to emerge on its surface. The surface water percentage of the sand is proportional to the area of the spread of black color that has emerged on the surface of the white paper after absorbing the surface water. Using a digital camera, the spread of the black color that emerges on the surface of the white paper is photographed. This information was imported into a computer, and the relationship between the surface water percentage of the sand, which was previously determined by calibration, and the area of the black color that emerged on the surface of the white filter paper after absorbing the surface water of the sand, was calculated. Measure the surface water content of the sand. The result of the calibration was: surface water content (%) = constant × (black area (cm ² )).

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Composite paper is made by laying black colored paper on the back of white ground paper. When this composite paper is made to absorb the surface water in the sand forcibly, the absorbed white filter paper passes through the light,
The black color of the black paper on the back is raised on the surface of the white paper. The spread of the black color that emerges on the surface of this white paper is taken with a digital camera. This information was imported into a computer, and from the relationship between the surface water percentage of the sand, which was previously determined by calibration, and the area of the black color that emerged on the surface of the white paper that appeared after absorbing the surface water, Measure the surface moisture of the sand.

[0006]

EXAMPLE A filter is fitted into the outer wall of an aggregate bin of a raw conplant. Suction device with filter,
Fix the filter with enough space for the composite paper to pass. The rolled composite paper passes between the filters and is wound around a winder via a guide roller. After opening the solenoid valve, the composite paper absorbs the surface water in the sand by operating the vacuum pump and sucking. The part that has absorbed the surface water causes the black color of the black paper under the rubbing paper to rise, and the surface of the composite paper appears black. After this state, the composite paper is wound on a winder, and when it comes out from between the filters, the spread state of the black color is photographed by a digital camera (10). The information is taken into the computer (11), and the surface water rate of the sand is obtained from the relationship between the surface water rate previously obtained by the calibration and the spread area of the black color emerging on the surface of the composite paper.

[0007]

According to the present invention, by directly and quickly measuring the surface water of the sand immediately before measurement for kneading concrete,
Correction to concrete mixing unit water amount by sand surface water can be performed accurately. As a result, the slump and strength of the concrete can be matched with the target values.

[Brief description of the drawings]

FIG.

[Explanation of symbols] Outer wall of aggregate bottle Filter Filter Suction device Composite paper (paper with black color paper laminated on the back of white filter paper) Rolled composite paper Guide roller Rewinder Solenoid valve ▲ 10 ▼ Digital camera ▲ 11 ▼ Computer

Claims (2)

[Claims] 1. A filter is passed through a composite paper obtained by laminating a white filter paper on top of a black paper face down to forcibly absorb water on the surface of sand, so that a water absorbing portion of the white filter paper has a black back on the back. The black color of the paper emerges. The spread state of the black color is captured with a digital camera. 2. The information on the spread of the black color taken by the digital camera is taken into a computer, and the surface water of the sand is determined from the relationship between the area of the spread of the black color and the surface water rate of the sand, which is obtained in advance by calibration. Measure the rate.