CN101419152A - Pervious template cloth permeability test method and device based on concrete slurry medium - Google Patents

Abstract

Translated fromChinese

本发明公开了一种基于混凝土浆液介质的透水模板布渗透性测试方法和装置，方法为：第一步，按混凝土施工配合比配制水泥砂浆，去除石子粗骨料后，灌入水泥砂浆，在完整渗透侧面敷上待测饱和透水模板布；第二步，向试样施加水平荷载，模拟实际模板工程中不同部位的混凝土浆体侧压力并保持稳定压力值，计算各相应计时单元的平均渗排水量和平均单元渗排速率。第三步，整理试验数据，获得综合时变渗透系数的实验表达式；第四、五步，改变试样配合比或调整侧压力值获得相应条件下综合时变渗透系数的实验表达式；第六步，获得综合时变渗透系数变化率ψ，第七步，测试试样饱和透水模板布试验前后的淤堵程度。

The invention discloses a method and device for testing the permeability of a permeable template cloth based on a concrete slurry medium. The method is as follows: the first step is to prepare cement mortar according to the concrete construction mix ratio, and after removing the coarse aggregate of stones, pour the cement mortar into the Cover the saturated permeable formwork cloth to be tested on the complete permeable side; in the second step, apply a horizontal load to the sample to simulate the lateral pressure of the concrete slurry at different parts in the actual formwork project and maintain a stable pressure value, and calculate the average permeable value of each corresponding timing unit. Displacement and average unit seepage rate. The third step is to organize the test data to obtain the experimental expression of the comprehensive time-varying permeability coefficient; the fourth and fifth steps are to change the sample mix ratio or adjust the lateral pressure value to obtain the experimental expression of the comprehensive time-varying permeability coefficient under corresponding conditions; The sixth step is to obtain the comprehensive time-varying permeability coefficient change rate ψ, and the seventh step is to test the clogging degree of the sample saturated permeable template cloth before and after the test.

Description

Pervious template cloth permeability test method and device based on concrete slurry medium

One, technical field:

The invention belongs to porous media material permeance property field tests, particularly a kind of pervious template cloth permeability test method based on concrete slurry medium.

Two, background technology:

Permeable template cloth is the non-woven class nonwoven fabrics of a kind of short fiber, liner is at the template face when being used for deposit concrete, ooze the excessive moisture and the gas of row's concrete slurry middle-shallow layer, reduce shallow-layer concrete slurry water cement ratio and air bubble content, improve the concrete curing condition simultaneously, thereby improve the closely knit performance and the apparent property of concrete surface layer.

Permeance property is one of important content of porous media material performance test.For the non-woven class nonwoven fabrics of short fiber, in building water conservancy class application in engineering mainly is its anti-filter of performance, drainage, water permeability template cloth product has been applied to engineering practice both at home and abroad at present, but its infiltration drainage performance theory of testing and method are still blank, individual product manufacturer is with reference to ISO/FDIS11058-98T (E) " the vertical permeability test when geotextile and Related product thereof do not have pressure ", ASTMD4716-87 " hydraulic conductivity (flowing) test under constant head of geotextile and Related product thereof " along the fabric plane, ISO/FDIS12958-98E " geotextile and Related product thereof are along the mensuration of fabric plane conveyance power of water ", " JTG E50-2006 highway geosynthetics testing regulations " and " geosynthetics test procedure " test specification or rules such as (SL/T235-1999), and two contents of test of vertical infiltration coefficient and horizontal permeation coefficient are arranged.The ultimate principle of test is based on that Darcy infiltration law principle carries out, test should be satisfied constant laminar flow seepage field condition, adopt and decide head or varying head method of testing, osmotic fluid medium (20 ℃ of saturated pure water) is the Newton body, in the experiment infiltration coefficient value be with seepage velocity v under the different constant heads and corresponding hydraulic slope J obtain the slope of regulated linear part represent the infiltration drainage performance of reflection porous media material itself.

There is following shortcoming in currently used these method of testings, and the first, concrete slurry is Bingham body but not Newton body, its infiltration rule does not satisfy above-mentioned simple Darcy infiltration law test philosophy; The second, decay stops the row's process of oozing of the excessive moisture of this test concrete slurry shallow-layer because of concrete initial set solidifies rapidly, is non-constant seepage flow; The 3rd, the permeable template cloth structure is divided into both surface filtration layer and internal layer horizontal drainage layer, since the permeable template cloth structure in real work because of the wall pressure effect of concrete slurry and ooze row's silting and cause it vertically and horizontal permeation performance coupling influence, so respectively separately the test permeable template cloth at constant laminar flow seepage field, decide horizontal coefficients and vertical infiltration coefficient under head or varying head and the aqueous fluid ambient condition, can not characterize its actual infiltration drainage works performance, must reselect suitable method of testing according to the permeable template cloth work characteristics.

Three, summary of the invention:

Can not characterize the shortcoming of its actual infiltration drainage works performance for the water permeability method of testing that solves the prior art existence, the invention provides a kind of pervious template cloth permeability test method and device thereof, the permeance property of the permeable template cloth under can actual response practice of construction state based on concrete slurry medium.

Technical scheme of the present invention is: a kind of pervious template cloth permeability test method based on concrete slurry medium, and step is:

The first step is dried permeable template cloth to be measured, weighing record dry weight; By concrete construction match ratio preparation sand-cement slurry, after removing the stone coarse aggregate, end face by sealing grid pad pours into sand-cement slurry, behind the vibration compacting, complete infiltration side at sealing grid pad applies saturated permeable template cloth to be measured, install the saturated permeable template cloth of sample to be tested by regulating increased pressure board, make sample saturated permeable template cloth to be measured be in not spillage, not slippage state;

Second step, apply horizontal loading to sample, simulate the concrete mortar wall pressure of different parts in the actual template engineering and keep the steady pressure value, timing simultaneously, ooze water discharge with the water leg collection, every 5min is a timing unit, calculates the water discharge that oozes of each timing unit, calculate each unit and ooze row's speed, when 90min or not draining, finish test; Be to eliminate test error, can be once, but permeable template cloth must change to same test condition repeated test, calculate each corresponding timing unit on average ooze water discharge and averaging unit is oozed row's speed.

In the 3rd step, the arrangement test figure is drawn the die-away curve of seepage velocity v-time T under this wall pressure condition according to formula (1), obtains to become when comprehensive infiltration coefficient (K by the exponential function match_C) the experiment expression formula;

$V=K_C\×J=\frac{Q}{A}---\left(1\right)$

(1) in the formula: V-seepage velocity (cm/s), K_C-become infiltration coefficient (cm/s), J-hydraulic slope (dimensionless), Q-seepage discharge (l/s), A-sample area (cm when comprehensive²).

The 4th step, change the sample match ratio, repeat the die-away curve that the test of first to three step can obtain different mixture ratio concrete slurry seepage velocity v-time T under the fixation side pressure condition, obtain to become when comprehensive under the corresponding match ratio experiment expression formula of infiltration coefficient by the exponential function match;

The 5th step, in like manner, adjust the wall pressure value, repeat the test of first to three step and can obtain different wall pressure each became infiltration coefficient (K when the corresponding test duration, section was comprehensive under than concrete slurry condition in secure fit_CThe influence curve of)-pressure (P);

The 6th step, establish and become the infiltration coefficient rate of change when comprehensive and be ψ, then ψ is K_CDerivative, that is:

$\mathrm{\ψ}=\frac{d\left(K_C\right)}{\mathrm{dt}}---\left(2\right)$

(2) in the formula: become infiltration coefficient rate of change (cm/s/min) during ψ-comprehensive;

The 7th step, the silting degree before and after the saturated permeable template cloth test of test sample, represent with following formula:

ζ＝[(G_D1-G_D0)/G_D0]*100％； (3)

ζ-sample silting degree;

G_D0Oven dry sample mass (g) before-test;

G_D1-test back oven dry sample mass (g);

Judge the silting degree of the saturated permeable template cloth of sample under the practice of construction state according to ζ.

Sealing grid pad described in the first step is made up of stiffness PE grid rectangular node pad and antiseepage cover, the antiseepage cover envelopes three faces in bottom surface, front, back of stiffness PE grid rectangular node pad and a face in the left and right side, and that side that coats is not as complete infiltration side.

A kind of device that is used for described pervious template cloth permeability test method based on concrete slurry medium, described device comprises pressue device, the counter-force support, guide rod, guide rail, increased pressure board and bedplate, the counter-force support is vertical at the right and left of bedplate respectively, on bedplate, the inboard of left side counter-force support is provided with water leg, inboard at right counter-force support is provided with increased pressure board, increased pressure board is connected with right counter-force support by guide rod, on bedplate, be provided with guide rail, pressue device is located between increased pressure board and the right counter-force support, and described pressue device is a hydraulic jack.

The present invention is according to the situation of oozing row's performance of the water permeability template cloth under the practice of construction state, use become that infiltration coefficient weighs permeable template cloth when comprehensive ooze row's performance, the implication that becomes infiltration coefficient when comprehensive is that oozing of consideration permeable template cloth arranged effect by the infiltrating on template cloth top layer of moisture in the slurry, comprise the fine grain silting of infiltrating of slurries, with embody along the gravity drainage compound action in the plane, also change simultaneously because of the variation of oozing row pressure power and time.Become when comprehensive the infiltration coefficient test into: setting under concrete mix W/B (W/B is the quality/gum material amount of the water) condition and setting under the wall pressure condition, the concrete slurry sample of measuring saturated vibration compacting is by the discharge capacity that oozes of tested each that permeable template cloth obtained identical continuous time of section, calculate and comprehensively ooze current drainage speed, consider that permeable template cloth mainly oozes row's performance and is embodied in water guide in the horizontal plane, oozing exclusion power in the vertical plane can ignore, think that it is mainly gravity water guide in the horizontal plane so be similar to, its hydraulic slope J=1, therefore, oozing current drainage speed v and can be similar to characterize and become coefficient of permeability K when comprehensive in the test different time elementary section_CBecome coefficient of permeability K when obviously, comprehensive_CIt is the exponential function curve of a decay.K_CThe influence factor of function curve is a lot, the material geometrical performance, slurry medium performance change, pressure attenuation that comprises permeable template cloth changes, particle silting degree and row are oozed and lasted etc., be horizontal permeation coefficient or vertical infiltration coefficient on the difference common meaning, become coefficient of permeability K when comprehensive so be defined as_CIn view of oozing in row's process, become coefficient of permeability K when comprehensive so defined because of the silting up of grout particle, different parts and the variation of different time point wall pressure and the condensation cure of concrete slurry cause the variation of oozing current drainage speed flow velocity_C, in order to permeance property and specific concrete mix, the concrete lateral pressure of expressing certain certain material geometrical performance permeable template cloth, ooze row and last mutual relationship.

Utilize controlled loading system to simulate actual concrete mortar and pour after the template wall pressure into infiltration template cloth, adopt stiffness PE grid rectangular node pad+only stay end face and complete infiltration side and other four sides all antiseepages cover of sealing constitute concrete mortar sample models, by given constant wall pressure, the draining rule of test sample, row speed and time relation curve are oozed in drafting, obtain change coefficient of permeability K when comprehensive_CThe fitting function of-t.

Beneficial effect:

1. in the method for testing of the present invention in conjunction with engineering practical application characteristics, the material geometrical performance, slurry medium performance change, pressure attenuation of having taken all factors into consideration permeable template cloth changes, particle silting degree and row are oozed factor such as last, and the present invention selects to adopt and becomes the permeance property that infiltration coefficient is weighed the permeable template cloth in the concrete slurry medium under the actual working state under test different pressures or the different mixture ratio when comprehensive.

2. utilize test method of the present invention and device, solved that the test permeable template cloth is variable in attached pressure and filter cloth silting, infiltration drainage performance and Changing Pattern problem thereof under the non-constant condition of seepage flow, what characterized permeable template cloth comprehensively oozes row's performance, and data are obtained the expression formula that becomes the infiltration coefficient fitting function when comprehensive by experiment.This experimental technique and parameter are used for engineering practice, can reflect the water permeability and the engineering scope of application of permeable template cloth exactly.

3. this invention is by test water permeability template cloth change indicator that lasts permeance property to concrete slurry under loading horizontal loading condition, can really characterize water permeability template cloth in practical work process oozing row effect and and factor affecting, realistic working condition plays a key effect to the row's performance of oozing of estimating water permeability template cloth.

4. design a sealing grid pad and substitute stone coarse aggregate in the concrete, the load that loads by controlling level or change the curve that concrete mix obtains seepage velocity and time or pressure, match obtains becoming when comprehensive the experiment expression formula of infiltration coefficient, finally obtains the expression of sample silting degree.

Four, description of drawings

Fig. 1 is a used test device synoptic diagram of the present invention.

Wherein drawing reference numeral explanation: 1-oil cylinder, 2-oil pump, 3-oil pressure gauge, 4-control surplus valve, 5-high-pressure oil pipe, 6-lifting jack, 7-counter-force support, 8-guide rod, 9-guide rail, 10-increased pressure board, 11-bedplate, 12-grid pad, 13-antiseepage cover, 14-permeable template cloth, 15-water leg.

When beingembodiment 1 comprehensive, Fig. 2 becomes coefficient of permeability K C measured value and fitting function curve map.

Five, embodiment:

Embodiment 1

Test certain brand permeable template cloth, the test concrete mixture ratio of configuration is as follows: cement: sand: stone: water: flyash: JM-9 water reducer=1:1.44:2.45:0.486:0.204:0.006; The wall pressure that test applies sample is 4Kpa; The sample area is 30mm * 0.113mm=3.39cm²Then can test following tables of data 1:

Table 1: survey interior sample of each unit period and ooze discharge capacity (Q) statistics

Follow-on test timeperiod sequence number	1	2	3	4	5	6	7	8	9
										The unit oozes water discharge (ml) in the period	41.28	32.58	19.02	16.32	13.02	7.38	5.94	4.98	3.66
Follow-on test timeperiod sequence number	10	11	12	13	14	15	16	17	18
										The unit oozes water discharge (ml) in the period	2.58	2.28	1.86	1.44	0.9	0.66	0.42	0.12	0.06

Annotate: each test cell period is 5min, the accumulative total follow-on test 18*5=90min.

Calculate following table 2:(according to formula (1) and get J=1 in calculating, then V=K_C)

Table 2: survey change coefficient of permeability K when sample is comprehensive in each unit period_C

Time point (min)	7.5	12.5	17.5	22.5	27.5	32.5	37.5	42.5	47.5
										Become infiltration coefficient (cm/s) when comprehensive	0.01218	0.00961	0.00561	0.00481	0.00384	0.00218	0.00175	0.00147	0.00108
Time point (min)	52.5	57.5	62.5	67.5	72.5	77.5	82.5	87.5	92.5
										Become infiltration coefficient (cm/s) when comprehensive	0.00076	0.00067	0.00055	0.00042	0.00027	0.00019	0.00012	3.5E-05	1.8E-05

Can draw Fig. 2 according to table 2.

Illustrate: the K among Fig. 2_C=0.0235e^-0.0669tBecome the time dependent fitting function of infiltration coefficient when comprehensive, wherein, K_C-become infiltration coefficient (cm/s) when comprehensive; T-row is oozed the time of lasting (min); R²-fitting function relative coefficient.

According to (2) formula, can get and become infiltration coefficient rate of change ψ function when comprehensive:

$\mathrm{\ψ}=\frac{d\left(K_C\right)}{\mathrm{dt}}=0.0235\×(-0.0669)e^{-0.0669t}(\mathrm{cm}/s/\min )$

According to (3) formula, can get sample silting degree:

ζ＝[(5.387-3.833)/3.833]*100％＝40.52％

At this moment, can change concrete mixture ratio, perhaps change wall pressure and repeat above step side again and get ζ under different mixture ratio or the different wall pressure.

The concrete course of work is as follows:

1, test template cloth is dried weighing record dry weight;

2, dispose the fresh concrete of certain match ratio by design proposal, sieve and reject stone coarse aggregate part, the residual concrete slurry is poured into grid pad sample model, with the metal bar vibration compacting ofφ 10;

3, attach the saturatedpermeable template cloth 14 of nature suction in the complete infiltration side that sample does not pasteantiseepage cover 13, sample be installed between increasedpressure board 10 and thecounter-force support 7, adjust the anchor clamps state, make sample be in slightly tightly spillage not, can not slippage stationary state;

4, apply constant wall pressure load by design proposal, the 5min that picks up counting is a timing unit, measures the row's water percolating capacity in thewater leg 15 simultaneously;

5, row's water percolating capacity of each timing unit of follow-on test is till 90min or sample stop to ooze draining;

6, behind the termination test, take out infiltration template cloth immediately, the silting degree is calculated in oven dry sample and weighing;

7, the row's of calculating infiltration rate rate v draws v-t curve;

8, adopt exponential function match experimental data, obtain becoming when comprehensive the infiltration coefficient fitting function.

9, change fresh concrete match ratio or change wall pressure, repeat above method step test, can obtain permeable template cloth permeance property and specific concrete mix, concrete lateral pressure, ooze to arrange and last mutual relationship curve and fitting function.

Embodiment 2

A kind of device that is used for described pervious template cloth permeability test method based on concrete slurry medium, described device comprises pressue device, counter-force support 7, guide rod 8, guide rail 9, increased pressure board 10 and bedplate 11, counter-force support 7 is vertical at the right and left of bedplate 11 respectively, on bedplate 1, the inboard of left side counter-force support 7 is provided with water leg 15, be provided with increased pressure board 10 in the inboard of right counter-force support, on bedplate 11, be provided with guide rail 9, pressue device is located between increased pressure board 10 and the right counter-force support 7, increased pressure board 10 is connected with right counter-force support 7 by guide rod 8, and increased pressure board 10 is done tangential movement along the guide rail of being located on the bedplate 11 9 by guide rod 8 between counter-force support 7.Described pressue device is a hydraulic jack, form by a lifting jack 6, oil cylinder 1, oil pump 2, oil pressure gauge 3, control surplus valve 4, high-pressure oil pipe 5, lifting jack 6 is located between increased pressure board 10 and the right counter-force support 7, lifting jack 6 is connected with oil cylinder 1 by high-pressure oil pipe 5, pressurize by the oil pump of being located on the oil cylinder 12, monitor by 2 pairs of pressure of oil pressure gauge of being located on the oil cylinder 1, by control surplus valve 4 control oil masses.

Claims (4)

1. the pervious template cloth permeability test method based on concrete slurry medium is characterized in that, step is:

The first step is dried permeable template cloth to be measured, weighing record dry weight; By concrete construction match ratio preparation sand-cement slurry, after removing the stone coarse aggregate, end face by sealing grid pad pours into sand-cement slurry, behind the vibration compacting, complete infiltration side at sealing grid pad applies saturated permeable template cloth to be measured (14), install the saturated permeable template cloth of sample to be tested (14) by regulating increased pressure board, make sample saturated permeable template cloth to be measured (14) be in not spillage, not slippage state;

Second step, apply horizontal loading to sample, simulate the concrete mortar wall pressure of different parts in the actual template engineering and keep the steady pressure value, timing simultaneously, ooze water discharge with water leg (15) collection, every 5min is a timing unit, calculates the water discharge that oozes of each timing unit, calculate each unit and ooze row's speed, when 90min or not draining, finish test; Change permeable template cloth, to same test condition repeated test once, calculate each corresponding timing unit on average ooze water discharge and averaging unit is oozed row's speed;

In the 3rd step, the arrangement test figure is drawn the die-away curve of seepage velocity v-time T under this wall pressure condition according to formula (1), obtains to become when comprehensive infiltration coefficient (K by the exponential function match_C) the experiment expression formula;

$V=K_C\×J=\frac{Q}{A}---\left(1\right)$

(1) in the formula: V-seepage velocity (cm/s), K_C-become infiltration coefficient (cm/s), J-hydraulic slope, Q-seepage discharge (1/s), A-sample area (cm when comprehensive²);

The 4th step, change the sample match ratio, repeat the die-away curve that the test of first to three step can obtain different mixture ratio concrete slurry seepage velocity v-time T under the fixation side pressure condition, obtain to become when comprehensive the experiment expression formula of infiltration coefficient by the exponential function match;

The 5th step, in like manner, adjust the wall pressure value, repeat the test of first to three step and can obtain different wall pressure each became infiltration coefficient (K when the corresponding test duration, section was comprehensive under than concrete slurry condition in secure fit_CThe influence curve of)-pressure (P);

The 6th step, establish and become the infiltration coefficient rate of change when comprehensive and be ψ, then ψ is K_CDerivative, that is:

$\mathrm{\ψ}=\frac{d\left(K_C\right)}{\mathrm{dt}}---\left(2\right)$

(2) in the formula: become infiltration coefficient rate of change (cm/s/min) during ψ-comprehensive;

The 7th step, the silting degree before and after the saturated permeable template cloth of test sample (14) test, represent with following formula:

ζ＝[(G_D1-G_D0)/G_D0]*100％；(3)

ζ-sample silting degree;

G_D0Oven dry sample mass (g) before-test;

G_D1-test back oven dry sample mass (g);

Judge the silting degree of the saturated permeable template cloth of sample under the practice of construction state according to ζ.

2. the pervious template cloth permeability test method based on concrete slurry medium as claimed in claim 1, it is characterized in that, sealing grid pad described in the first step is made up of stiffness PE grid rectangular node pad and antiseepage cover, antiseepage cover (13) envelopes three faces in bottom surface, front, back of stiffness PE grid rectangular node pad and a face in the left and right side, and that side that coats is not as complete infiltration side.

3. device that is used for the described pervious template cloth permeability test method based on concrete slurry medium of claim 1, it is characterized in that, described device comprises pressue device, counter-force support (7), guide rod (8), guide rail (9), increased pressure board (10) and bedplate (11), counter-force support (7) is vertical at the right and left of bedplate (11) respectively, on bedplate (1), the inboard of left side counter-force support (7) is provided with water leg (15), be provided with increased pressure board (10) in the inboard of right counter-force support, increased pressure board (10) is connected with right counter-force support (7) by guide rod (8), be provided with guide rail (9) on bedplate (11), pressue device is located between increased pressure board (10) and the right counter-force support (7).

4. as claimed in claim 3ly it is characterized in that based on the device in the pervious template cloth permeability test method of concrete slurry medium described pressue device is a hydraulic jack.

Images