SU877371A1 - Method of capillary pressure determination in a capillary porous body - Google Patents

Description

I

The invention relates to a technique for measuring pressure in capillary-porous-bodies, preferably in soil grounds, peat x and construction materials.

A known method for measuring negative capillary pressure is based on the introduction of a tube with a porous plug into the test material. The tube contains the same fluid as the test material. At. the occurrence of negative capillary pressure in the test material creates a negative pressure in the tube, which is measured using an aqueous or other manometer. When measured in a known manner. obtain data on the averaged values of capillary pressure 1

The disadvantages of this method include the low accuracy and small range of measured pressures.

There is also known a method for determining the negative capillary pressure in a capillary-porous body, based on the introduction of a dead-end microcapillary into the micropore of a capillary-porous body. The capillary is introduced by the open end into contact with the liquid, which, under the action of capillary forces, rises to the capillary for a certain height. The negative capillary pressure arising in the micropore with microcapillary rum causes a change in the level of fluid in it. From the magnitude of the level change, the value of the intended capillary pressure G21 is calculated.

The disadvantage of this method lies in the fact that during the measurement, the capillary is introduced into the pore capillary-porous body, and the pore size is comparable with the size of the capillary tube and

The reduction of negative capillary pressure occurs only for a given micropore, and the natural course of the process of changing capillary pressure in it is disturbed by the introduction of a capillary.

The purpose of the invention is to scale up the measurement and obtain averaged values of capillary pressure.

.. The goal is achieved by JTCM. that a dead-end microcapillary is inserted into a model capillary-porous body, which is then inserted into the capillary-porous body under study. Model capillary-porous body, on. An example of a porous ceramic bead is moistened with a liquid — with a known surface tension coefficient; ..

The capillary pressure of the model body comes to equilibrium with the capillary pressure in the material under study, and by changing the level of the liquid in the microcapillary re, the capillary cap is investigated.

GavlevniJH by the known formula. In this case, the averaged value is measured.

capillary pressure, characteristic of this area of the capillary-porous body, and microcapillary ps serves as a highly sensitive micromanometer. The proposed method for determining capillary pressure allows us to significantly increase the accuracy and improve 4-5 times; it can be applied in the study of physicomechanical and thermophysical properties of building materials, hills, soils and other dispersions of materials.

Claims (2)

1. Korchunov S.S., Nogilevsky, G.I. and others. Study of the water regime of drained peat deposits. Proceedings of VNIITP, 1960, -vp. 17 2. The author's certificate of the USSR 587346, cl. G 01 L 7/00, 1975 (prototype).