Device and method for continuously measuring saturated surface dry state of pre-wetted aggregate

Abstract

The invention relates to a device and a method for continuously measuring a saturated surface dry state of pre-wetted aggregate, belongs to the technical field of preparation of concrete materials, and aims to provide a simple lightweight aggregate saturated surface drying device, so that the lightweight aggregate with the wet surface can rapidly reach the saturated surface drying state. The method comprises the following steps: firstly, measuring the standard water absorption rate of the dry aggregate in a saturated surface dry state; secondly, before the dry aggregate is pre-wetted, weighing the mass of the dry aggregate in a hopper; then, calculating and obtaining the moisture content of the batch of aggregate in a surface dry and saturated state; then, after the dry aggregate is pre-wetted, weighing the mass of the pre-wetted aggregate in the hopper; then, loading the wet aggregate on a porous plate, feeding the porous plate into a drying chamber for drying treatment, and measuring the relative humidity of the drying chamber; then, calculating the moisture mass in the drying chamber; then respectively weighing the mass of water flowing out of a water collecting tank below the porous plateand the mass of condensate water in a heat exchanger; and finally, calculating the actual water carrying amount in the dried saturated surface dry aggregate when the water content is close to the water content in the aggregate surface dry and saturated water state.

Description

technical field [0001] The invention relates to the technical field of concrete material preparation, in particular to a device and method for continuously measuring the saturated surface dry state of pre-wet aggregate. Background technique [0002] Aggregate in a saturated surface dry state means that the internal pores of the aggregate are all saturated with water, but there is no moisture on the surface. Saturated surface-dry state is an important technical index of aggregate during concrete mixing. Large-scale projects often use saturated surface-dry aggregate as the benchmark for concrete preparation. The main reason is that for concrete, especially high-performance concrete, water content is a key determinant of concrete flow properties and construction performance. Excessive fluctuations in the water content of concrete will directly affect the water-binder ratio of the cementitious material, thereby affecting the mechanical properties of concrete. After the saturat...

AI Technical Summary

Problems solved by technology

If you only use absorbent towels to absorb surface moisture, the moisture in the middle and bottom of the aggregate pile cannot be removed

On the other hand, during the continuous conveying of aggregates, it is difficult to install a load cell under the conveyor belt or chain plate, and interference factors such as mechanical vibration will also have a non-negligible impact on the sensor’s weighing. Therefore, the weighing method is very difficult. Difficult to apply to continuous production process

At present, there is no effective measurement method for the saturated dry state of large quantities of aggregates in production.

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