SU1516892A1 - Method of determining water-absorption of porous fillers - Google Patents

Abstract

The invention relates to the determination of the physicomechanical properties of building materials and can be used in lightweight concrete technology in the selection of its composition. The purpose of the invention is to improve the accuracy of the results of determining the water absorption of porous aggregates and to expand the technological capabilities of the method. The method is carried out as follows. Weigh out a given mass of a sample of a specific fraction that has been dried to a constant mass. The average grain diameter D of the dry aggregate is determined and the time T of the aggregate on the sieve is determined by functional dependence. With 0.14≤D≤8, with 8≤D≤30, T = -0.06D ² + 1.39D + 2.75 (1), T = 0.003D ² -0.52D + 14.24 (2 ), where D is the average grain diameter of the dry aggregate, mm, T is the aging time of the aggregate on the sieve to drain gravity water from the surface of its grains, min. Next, the filler is placed in a vessel with water and kept in it for a specified time. Then the saturated aggregate is removed from the vessel, placed on the inclined sieve 1 and kept for the time T calculated by the formula (1) or (2). Next, the aggregate is removed from the screen and weighed. The difference in the mass of dry and water-filled aggregates determines the amount of water absorption. 2 Il.

Description

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The invention relates to the field of the definition of physicomechanical (cDoiicTD) building materials and can be used in the technology of lightweight concrete to select its composition.

The aim of the invention is to improve the accuracy of the results of the determination of the hygro-absorption and the expansion of technological capabilities by reducing the iHCKHef i limit of the size range of the filler grains and by eliminating shaking and wiping the grains of the sample DL for removing gravity water.

FIG. 1 shows a device with which the method is carried out; pas figs. 2 is a graphical dependence of cpebieHH stenan of gravitational iodine on the average grain diameter of a dry aggregate.

A device for implementing the method comprises a standard sieve 1 and a stand 2, allowing the sieve to be placed in the collapsed condition.

The method is carried out as follows.

Weigh out the set weight of the sample, dried to a constant weight, of the aggregate of a certain fraction. The average diameter of the skull c1 of the dry aggregate fraction tested is determined by the following functional dependencies:

t -0.06d AND, 39d + (1)

at O, l - d - S

+ 2.75 with 8 d i 30

n - 4.24,

t 0,003d -0,52d +

(2)

determine the time t for keeping the water-pasisheped: 1 napolpitele on a sieve for draining excess water from the surface of the skull} 1 (gravitational) water. Next, the zaplopitel is placed in a vessel with water, overlaid with a network: oh with the weights to prevent the emergence of grains and kept in the vessel for saturation with water for a period of time according to technical conditions. Then, the water filled zagonger is removed from the vessel with water, placed with the separation of the grains on a standard sieve 1 with cell sizes corresponding to the minimum grain size of the tested fraction titanitji. The filler 3 (Fig. 1) is kept on an inclined sieve for drainage from the surface of grains of gravitational water for a time t, calculated (2)

20

- - according to dependencies (1) or (2) for the tested fraction of the filler with an average grain diameter d.

During the holding of the filler on the sieve, excess (gravitational) water flows from the surface of the grains under the force of gravity onto the plane of the sieve and then flows down the inclined plane of the sieve to the lower part of it, where it is removed with a tampon. Next, the aggregate is removed from the surface of the sieve, placed on the scale and weighed. By the difference of the known masses

 the water content and dry samples of the aggregate are determined using a known calculation method to determine the amount of water absorption.

Claims (1)

Invention Formula The method of determining the water absorption of porous aggregates, including saturating a sample of the aggregate with water, then removing it from water and placing the water filled aggregate on a sieve, separating the aggregate grains, keeping it on a sieve for draining gravity water from the grain surface, weighing and determining absorption by the difference of the weights of the sample to the water pressure and after the saturation and flow of gravitational water, which is different, in order to increase the accuracy of the results and expand the technological their capabilities by reducing the lower limit of the size range of the aggregate grains and by eliminating shaking and rubbing the grain of the sample to remove the gravity water, determine the average grain diameter of the dry aggregate, and set the duration of maintaining the bulk aggregate on the sieve, I ensuring full draining of the gravity water, depending on the average grain diameter of the dry aggregate according to the following relationship: at 0.14 d 8 t -0,, 39d-f + 2.75; 50 8 d 30 t 0,003d - 0,52d + 14,24, where d is the average grain diameter of the dry filler, mm; t is the holding time of the filling-55 l on a sieve for the flow of gravitational water from the surface of its grains, min. thirty 35 40 45 I H and one h II V 12 fS 20 2U 8 JO fft / ai frnp jfflfft. l / a FIG. 2 Compiled by L. Prokopyeva Editor N, Bobkova Tehred A. Kravchuk Proofreader c. Cabing Order 6382/44 Circulation 789  State Committee for Inventions and Discoveries under the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., D. 4/5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 Subscription