SU1416476A1 - Method of producing concrete mix with porous aggregate of varying humidity - Google Patents

Abstract

This invention relates to a technology for preparing a benign blend on porous aggregates of varying humidity. The purpose of the invention is to improve the workability of the concrete mix and stabilize its temperature. The method of preparing concrete mixes on porous variable humidity aggregates includes filling the dispenser with water, feeding the aggregate to the dispenser, loading the dosed aggregate into the mixer and mixing it with cement, and after the aggregate is fed into the dispenser, the aggregate and water are weighed and the mass of excess water in the dispenser is determined by the difference between the mass of the aggregate and water and their mass required for the batch, after which the excess water is removed from the dosing unit, and the aggregate and the remaining water are loaded into the mixer. The method provides improved workability of the concrete mix and levels its temperature. i (L

Description

C5

ABOUT

ten

11416476

This invention relates to a process for the production of building materials, namely the preparation of concrete mixtures on porous aggregates of variable humidity.

The purpose of the invention is to improve the smoothing of the concrete mix and stabilize its temperature.

Example. In winter, it is necessary to prepare a concrete mix on a porous aggregate of variable moisture content: cement 320 kg, thermosite foam 1.12 m (1165 kg), water 280 l, the temperature of the concrete mixture required by the customer at an outside air temperature of -15 ° С is equal to , the initial temperature of the aggregate and cement is equal to the outside air temperature., 20

Under laboratory conditions, the volume of each batch is 6 liters. Three batches were made with a variable humidity aggregate of 0.6 and 12%, respectively. The composition per batch with a volume of 6 l is determined by multiplying by 0.006, thus: cement 320 &

Before filling the dispenser with water with a given initial temperature (water is heated to 95 ° C), its volume is determined using the heat balance formula, and the heat balance formula

about

25 B

thirty

.

l

 0.2- (tu.-U + tn-n) + tn-Bn + te-B

c-, 2 Hz + p7 + Bp + c

where 0.2 is the specific heat capacity of the dry components of concrete; temperature of cement, sand, water, ° С;

C, P, B - cement, sand and water consumption in kg per 1 m of concrete or per batch J, - moisture content in sand,

kg,

transformed in relation to the conditions described in the proposed method as follows. Since after equalizing the temperature of the filler and water they have the same temperature, then after removing the excess water from the dispenser, there remains an amount of water equal to the amount of mixing water B, and the amount of aggregate is equal to P, and the BP is then 0, Jgda

0

50

s

 0.2 (Hz. SC + 1vp n) + ten-B

 about 75 shopping center + pt

whence at the required temperature of the mixture T ,, and a given composition of concrete t g is found:

0.2-Tc (U-bn) -Hj., 2-t4-H- -ten (0.2P +

+ B);

Te- (0,2-U + 0,2.n + B) -0,2.t.U tgri- (0,2x

n-i-B);

 Tc- (Oj 2U + Oj, 2n + BJ-0 2ty-lJ 8P0.2 P + B

Knowing what temperature the aggregate should have and water after equalizing their temperatures, find the volume of water with a given temperature that needs to be filled in the dispenser: first, the heat balance equations for the system are made. Water - aggregate in the dispenser

BZ t3 + 0,2-n-t {+ Bn tn tBfT (0,2n + Bn4.Bj); 5 B3-t3 + 0,2n tn-t-Bn-t ;; 0,2 n-tvp + Bn-tv „- + B 3 t rp; B, - (t3-t8n (0,2-n + Bn) - (tgft-tl;);

0

0

five

0

five

3., (0,2-n + Bn) - (ten-tn)

.---- - --- J

where B .J is the volume of water with a given temperature introduced into the tj dispenser, l;

t is the specified water temperature, C;

t is the initial temperature of the aggregate, C. Substituting the initial data into the formulas, find the volumes of water to obtain a concrete mix of the required temperature; with a filler with a humidity of 0.6 and 12%, they are respectively 1.8; 2.34, 2.88 l.

Then pour the required amount of heated V9DY into the dosing unit (measuring cylinder), pour the thermosit sand to the mark of 6.72 l, maintain the aggregate and water in the cylinder for 2.5 minutes (the drain time is determined by the rate of decrease in water temperature and at a different aggregate size must be taken into account) and at the same time determine the weight of excess water by the difference between the weight of water: and thermoset in the metering unit and the weight of them required for the batch. Excess water is then removed from the dispenser through a faucet. Thermosite sand and water left in the dispenser are poured out.

14

into the mixer. Then weigh 1.92 to the cement and pour it into the mixer too. Then mix the components of the concrete mix loaded into the mixer to a given uniformity. After mixing, the temperature of the concrete mixture and its mobility are determined (mobility is an indirect characteristic of the concrete composition).

Indicators for the use of aggregates of different humidity are given in the table.

The use of the proposed method in comparison with the prototype provides for the expansion of the technological possibilities for obtaining a concrete mix with the required composition and temperature due to its use when using a filler with a void exceeding the water demand of the concrete mix and by using the energy of water. It is possible to use a porous aggregate with a voidness that exceeds the water requirement of the concrete mixture, because the proposed method

This removes restrictions on the amount of water used to dispense the aggregate in it.

five

Claims (1)

Invention Formula The method of preparing a concrete mix on porous aggregates of variable humidity, including filling the dispenser with water, supplying the aggregate to the dispenser, loading the dosed aggregate into the mixer and mixing it with cement, which is different from - with the aim of improving the workability of the concrete mix and stabilizing its temperature , after the filler is supplied to the metering unit, the aggregate and the water in the metering unit are weighed, the weight of the excess water in the metering unit is determined by the difference between the weight of the aggregate and the water in the metering unit. D and their weight required for kneading, and then removed from the dispenser the excess water and filler and the remaining water was charged to the mixer. 39 38 40 30-60 3.0 3.3 3.1 -4 Compiled by O. Motorina Editor N. Kishtulinets Tehred L. Serdyukova Order 4029/2 Circulation 594 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Proofreader N.Korol Subscription