CN205374240U - Loading concrete pore structure evolution normal position monitoring devices - Google Patents
Loading concrete pore structure evolution normal position monitoring devices Download PDFInfo
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- CN205374240U CN205374240U CN201520976840.1U CN201520976840U CN205374240U CN 205374240 U CN205374240 U CN 205374240U CN 201520976840 U CN201520976840 U CN 201520976840U CN 205374240 U CN205374240 U CN 205374240U
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Abstract
Loading concrete pore structure evolution normal position monitoring devices, including ion mobility unit, resistance measurement unit, loading unit and data processing unit, the ion mobility unit include two band -pass holes flange pressure disk, liquid feeding pipe, fluid infusion basin and to drawing the screw rod, the resistance measurement unit include signal generator, coil, magnetic core and current sensor, the loading unit include that the concrete axle draws the test piece, adorns and draw bearing the weight of the steel sheet, take internal screw thread T type built -in fitting, bearing the weight of screw rod and load transducer of test piece both ends in the concrete axle, the data processing unit include signal collector, signal processor and central controller. The beneficial effects of the utility model are that: break through the restriction big or small to the sample of traditional test method, drawn the load through apply the axle to the test piece, the normal position monitoring of concrete pore structure evolutionary process under the loading, concrete interconnected pore rate that records and load size directly are applied to the concrete structure durability with the relation of porosity and are foreseeed.
Description
Technical field
This utility model relates to concrete hole structure determination technical field, particularly relates to a kind of contactless Impedance Determination and is drawn the in-situ monitoring device of load action concrete interconnected pore structure evolution by axle.
Background technology
Concrete is a kind of porous material, has a wide range of applications in civil engineering structure.Along with global economy is fast-developing, construction scale is unprecedented, and cement-based material makes consumption rise year by year, and the China for rapid economic development is especially prominent.China is a developing power, it is working on large-scale infrastructure construction, but the various resources of China and the energy do not enrich, therefore with greater need for from strategic height, reasonably utilize limited resource, scientifically design safety, be suitable for and durable engineering project, more to continue the service life of existing infrastructure as far as possible.
The reinforced concrete structure being in marine environment, spreading in cryosel environment and industrial environment, owing to villaumite, moisture and oxygen arrive rebar surface thus causing reinforcement corrosion by concrete pore, can be substantially reduced the service life of xoncrete structure.The concrete structure durability problem caused by steel bar corrosion, it has also become international research hot issue.According to statistics, concrete structure erosion is destroyed the loss caused by environment, and some country can reach the 2%～4% of gross national product.Hole in concrete is divided into open pore, half-open oral pore and blind hole.Etching medium except being affected by ambient temperature and humidity, depends primarily on concrete open communication porosity to the transmission speed in concrete.Accurate Determining concrete interconnected pore rate is the key of prediction concrete opposing etching medium transmittability.Nowadays, the mensuration of concrete pore rate generally adopts mercury injection method.The measurement result of mercury injection method, easily by the impact of mercury pressure, records porosity and generally includes intercommunicating pore and the semi-connected hole of part, and real what provide passage for medium transmission is interconnected pore.Restriction due to the technology of being put to the test and pressure hydrargyrum principle, test concrete porosity, way of today is by concrete disintegrating, then takes the mortar part in concrete and carries out Mercury injection test, and specimen size generally only has size (about diameter 5mm) as Semen Glycines.Visible, mercury injection method tests concrete porosity, is actually the porosity testing mortar, it does not have comprise coarse aggregate.Reinforced concrete structure in practical application, concrete is inevitable all comprises coarse aggregate.Truly to measure concrete interconnected pore rate, need to comprise coarse aggregate, and to ensure the uniformity of coarse aggregate in concrete, the usual test specimen length of side is greater than 2.5 times of aggregate sizes, if maximum size of coarse aggregate 25mm, the test specimen cross section length of side at about 65mm, should adopt conventional test methodologies to be difficult to accomplish.
It is true that concrete is the three-phase composite material comprising coarse aggregate, fine aggregate and cement stone substrate, pore (also has less gel pore) and is then primarily present in cement stone substrate.There are some researches show, the interfacial transition zone of aggregate and Behavior of Hardened Cement Paste is also the region that voids content is higher.If adopting mortar to reflect concrete pore character, the impact of coarse aggregate can not measure very well, and the interfacial transition zone between coarse aggregate and cement stone substrate can be left in the basket.Want the anti-erosion medium resistance ability of Accurate Prediction xoncrete structure, it is necessary to accurate quantitative analysis concrete interconnected pore rate.Based on contactless impedance method, Chinese patent Authorization Notice No. CN102539928A, authorized announcement date is on July 4th, 2012, name is called " the contactless impedometer being applied to analyze cement-based material pore structure ", provide a kind of contactless impedometer being applied to analyze cement-based material pore structure, the impedance in physically or chemically process status change procedure and complex resistivity is experienced for measuring samples, Chinese patent Authorization Notice No. CN12226824B, authorized announcement date is on July 31st, 2013, name is called " in hot environment concrete forming process the measurement apparatus of change in resistance and method ", disclose measurement apparatus and the method for change in resistance in a kind of hot environment concrete forming process.These two patents adopt electrodeless eyes with non-contact methods to analyze cement-based materials or pore structure law of development of concrete early age (in usual 7 day age), but can not to after maturation (after usual 28 day age) concrete carry out pore structure quantitative analysis.
Xoncrete structure in military service process is all want bearing load effect, and its axis draws load that the impact of concrete hole structure is the most obvious.Load action can make concrete hole architectural feature change, inside concrete also can be made to produce microcrack along with load increases, the continuous generation of microcrack can increase concrete pore communication, reduce concrete pore tortuosity, even can increase concrete porosity, thus cause that under different load level, etching medium is different to inside concrete transmission performance.Conventional test methodologies, as electric flux method, RCM method etc. carry out the pore property in semi-quantitative analysis concrete mainly through chloride ion fast transferring in concrete pore under electric field action.The test specimen section sample preparation that the concrete component coring sample preparation from bearing load or laboratory prepare is needed during due to test, put on concrete load during actual test to lay down and cannot be further applied load in testing, also just cannot record concrete pore property under bearing load state, same test block more cannot be adopted to complete the quantitatively characterizing of concrete hole architectural feature under different load.
Generally, concrete is applied axle and draws load to have bigger difficulty, essentially consist in, when concrete sample applying axle is drawn load axis centering difficulty easily occur, loaded, bias easily occurs, often lead to test failure.Therefore, current research and in existing patent documentation, material is applied axle and draws load, it usually needs by means of self-balancing reaction frame, jack and reduce the measures such as eccentric ball pivot.Such as, Chinese patent notification number CN104330314A, Shen Qing Publication day is on February 4th, 2015, name is called " clamping mechanism for superhigh temperature ceramics high temperature uniaxial direct tensile strength testing device ", Chinese patent Authorization Notice No. CN103175733B, authorized announcement date is on July 2nd, 2015, name is called " the direct tensile test fixture of incompressible material ", Chinese patent application publication No. CN103267682A, Shen Qing Publication day is on August 28th, 2013, name is called " under tension and environment coupled action the test device of material creep and method of testing ", draw at concrete axial and test method has had a lot of innovation, but assay device relative complex.
Therefore, research and develop a kind of easy and simple to handle, can Accurate Determining concrete interconnected pore rate and by easier loading method, concrete can be applied axle and draw the assay device of load, thus really realizing the quantitatively characterizing of concrete hole structure evolution under load action, there is highly important construction value, the evolutionary process of concrete hole structure under load action can be carried out in-situ monitoring, thus carrying out concrete material performance evaluation and endurance quality prediction, scientific research and engineer applied all being had and has very important significance.
Summary of the invention
In order to overcome the deficiency of existing mensuration concrete interconnected pore rate experimental technique, this utility model provides a kind of stability high, easy and simple to handle, being capable of axle draws load to apply, the assay device of concrete hole structure evolution process in-situ monitoring under the rate test of concrete interconnected pore and load action, particularly relate to the contactless resistance technique of application, axle draws load applying method and pore structure evolution in-situ monitoring technology, and be applicable to measure concrete interconnected pore rate and assess concrete erosion-resisting characteristics, to solve to there is no at present the load action concrete hole structure evolution in-situ monitoring device of the in-situ monitoring problem of concrete hole structure evolution under effective ways mensuration load action.
Load action concrete hole structure evolution in-situ monitoring device described in the utility model, it is characterized in that: include ion migration unit, resistance measurement unit, loading unit and data processing unit, described ion migration unit includes two with the flange platen of through hole, liquid-feeding tube, fluid infusion tank and Screw arbor with nut at both-ends, the corresponding flange platen of each port of described liquid-feeding tube；The two-port of described liquid-feeding tube is inserted in its through hole from corresponding flange platen outer face respectively；Two flange platen inner faces relatively and form the test chamber for clamping test specimen to be measured by Screw arbor with nut at both-ends, by rubber ring seal between flange platen and test specimen to be measured；Described fluid infusion tank and described liquid-feeding tube pipeline connection；
Described resistance measurement unit includes signal generator, coil, magnetic core and current sensor, and described liquid-feeding tube is affixed with corresponding flange platen after sequentially passing through magnetic core and current sensor；Described coil is wrapped on described magnetic core, and the signal input part of described coil two ends and described signal generator is electrically connected；
Described loading unit include concrete axial draw test specimen, be loaded on concrete axial and draw the carrying steel plate at test specimen two ends, tapped T-shaped built-in fitting, carrying screw rod and load transducer, described concrete axial draws test specimen to be provided with the reserved through hole of axial arranging, described concrete axial draws test specimen two ends pre-buried multiple T-shaped built-in fittings respectively, and the thread segment of described T-shaped built-in fitting points to concrete axial and draws outside test specimen；Described carrying screw rod runs through reserved through hole, and nut is configured at described carrying screw rod two ends, described nut side is furnished with carrying steel plate, and the thread segment of described T-shaped built-in fitting is spirally connected with fastening bolt, it is ensured that described carrying steel plate draws test specimen end face to fit with described concrete axial；Described load transducer is arranged on described concrete axial and draws test specimen sidewall, and the signal output part of described load transducer and the signal picker of data processing unit are electrically connected；
Described data processing unit includes signal picker, signal processor and central controller, the signal output part of the input of described signal picker and described current sensor is electrically connected, the signal output part of described signal generator, described signal picker outfan be electrically connected with the signal input part of described signal processor respectively, the signal output part of described signal processor is electrically connected with the corresponding port of described central controller.
Liquid-feeding tube is loop configuration；Liquid-feeding tube is provided with liquid flowing valve and draining valve, and wherein said liquid flowing valve is arranged on the line connection being connected with fluid infusion tank, and described draining valve is arranged on the bottom of liquid-feeding tube；Fluid infusion tank is connected with described liquid-feeding tube by flexible pipe.
Flange platen top is provided with passage, and wherein said passage one end connects with described through hole, the other end and flange platen ft connection.
Liquid-feeding tube adopts the bakelite of non-conductive class, polyurethane plastics, epoxy plastics, unsaturated polyester plastic, organic siliconresin or allyl resin class material to make.
The through hole of flange platen is stepped hole, and the through-hole diameter of the inner face of described flange platen is more than the through-hole diameter of outer face, and described passage wherein one end connects with the through hole of the inner face near described flange platen.
Be spirally connected after bolt connecting hole on split bolt two ends traverse flange platen two fastening nuts, and wherein said fastening nut adopts aerofoil profile STAINLESS STEEL NUTS.
Described concrete axial draws the reserved through hole of test specimen to be arranged on concrete axial and draws the geometric centroid place of test specimen, and keeps the central shaft of reserved through hole to overlap with the central shaft of concrete axial tensile test specimen.
Described concrete axial draws the two ends of test specimen to be provided with the pit coaxial with reserved through hole, and the size of pit is mated with nut；Described concrete axial draws the two ends of test specimen to leave outstanding flange, and the edge of a wing and concrete sample are with wide.
Described carrying steel plate is arranged installs through hole and the reserved circular hole corresponding with reserved through hole one to one with fastening bolt, and wherein said reserved circular hole is arranged on the geometric centroid place of carrying steel plate, and reserved circular is round the faulting of slab ends mated with nut；Described nut is placed in concrete pit and carrying steel plate faulting of slab ends；The screw diameter of described carrying screw rod mates with reserved through hole, and screw rod two ends are with external screw thread, and screw rod two ends have the parallel surface for spanner clamping, and two ends hand of spiral is contrary, and described carrying screw rod forms self-locking structure with described nut.
Described load transducer adopts foil gauge, amesdial or displacement transducer.
Utilize device described in the utility model to carry out load action concrete hole structure evolution in-situ monitoring method, comprise the following steps:
1) preparation of concrete test specimen to be measured:
The test of concrete hole structure evolution in-situ monitoring is damaged for load, build dumbbell shape test specimen, by test piece maintenance to setting age, it is dried to constant weight in an oven, then concrete sample to be measured is soaked in normal concentration saline solution or the full salt of vacuum is saturated to hole, the concentration of described standard chlorination sodium solution is 0.1～2mol/L, axle draws test specimen remove two opposition side other region epoxy resin extra-regional to be tested or paraffin seals；
2) preparation before measuring:
Normal concentration saline solution and step 1 is ensured before experiment) the full salt concrete sample to be measured temperature that obtains is identical, and two flange platens are sealed docking, and in liquid-feeding tube, perfusion normal saline solution is with calibrating instrument, and determines the electricalresistivityρ of normal concentration saline solution0；After demarcation terminates, drain normal saline solution, concrete sample to be measured for full salt and rubber seal contact position are coated with a little vaseline to increase sealing, then the liquid-feeding tube being connected to flange platen is sealed fastening with full salt concrete sample to be measured and become a sealing entirety, again in liquid-feeding tube, irrigate normal saline solution, selecting NaCl solution in test, the concentration of NaCl solution is 0.1～2mol/L；
3) electricalresistivityρ measures:
The sample frequency of data collecting system is set, data handling system automatically gathers faradic current and voltage from determination of resistivity system, calculation procedure calculates resistivity according to formula (1), and show change in resistance rate curve in real time, when change in resistance rate versus time curve is close to horizontal linear, resistivity value now is concrete test block resistivity under normal saline solution saturated conditions:
In formula, ρ is the resistivity (Ω m) of test specimen to be measured, and V is inductance loop voltage (V), I be inductance loop electric current (A), S is the effective cross-sectional area (m of test specimen to be measured2), L is the thickness (m) of test specimen to be measured；
Draw test specimen classification applying axle to draw load by countershaft, record resistivity corresponding under load at different levels respectively；
4) porosity φ measures:
The relation of resistivity and porosity can be obtained, such as formula (2) according to Archie equation.Apply it to concrete interconnected pore to calculate, then calculated concrete interconnected pore rate φ by formula (2) again by the concrete resistivity value of mensuration:
In formula, ρ is concrete resistivity (Ω m), ρ0For the resistivity (Ω m) of normal concentration saline solution, φ is porosity, and α and m is fitting coefficient；
According to step 3) different resistivity that measures, calculate concrete interconnected pore rate corresponding under different load level respectively.
The liquid-feeding tube of ion moving system described in this utility model fills the saline solution of concentration known, saline solution can be supplemented by fluid infusion tank, flange top is provided with passage, it is ensured that add that saltwater injection is smooth and easy and saline can be full of whole liquid-feeding tube cross section, and after off-test, saline solution is discharged by draining valve.Test specimen to be measured is positioned between two flange platens, by seal with elastometic washer between flange platen and test specimen to be measured, with Screw arbor with nut at both-ends mounting flange platen and test specimen to be measured.
The rubber washer that this utility model uses is circular cross section along circumferential direction, the diameter of rubber washer changes with flange platen size, test specimen net sectional area to be measured, test specimen effective cross-section size range to be measured is the circular cross-section of diameter 50mm～150mm, that is the circular cross section that effective cross-section region is diameter 50mm～150mm that concrete test block ion to be measured passes through.
The liquid-feeding tube of ion moving system described in this utility model fills the saline solution of concentration known, saline solution can be supplemented by fluid infusion tank, flange top is provided with passage, it is ensured that add that saltwater injection is smooth and easy and saline can be full of whole liquid-feeding tube cross section, and after off-test, saline solution is discharged by draining valve.Test specimen to be measured is positioned between two flange platens, by seal with elastometic washer between flange platen and test specimen to be measured, with Screw arbor with nut at both-ends mounting flange platen and test specimen to be measured.
Carrying screw rod described in the utility model and supporting nut have auto-lock function, along a direction rotary screw, two ends nut can produce thrust, when rupturing suddenly occurs in test specimen, the nut at screw rod two ends can pin divided into two parts concrete sample, it is to avoid test specimen suddenly rupture separate danger.Nut described in the utility model can be placed in concrete groove and upper lower bearing steel plate faulting of slab ends, prevents nut from rotating with screw rod during rotary screw.Upper lower bearing steel plate described in the utility model, fastening bolt and T-shaped built-in fitting can fasten as entirety before casting concrete, the template used end mould of test specimen is drawn as casting concrete axle, can ensure that the accurate pre-buried location of T-shaped built-in fitting, upper lower bearing steel plate and fastening bolt can Reusabilities.Load transducer described in the utility model adopts punching sensor, and in order to reflect the size of load level, punching sensor is embedded in the circular hole of upper bearing steel plate by cover plate and bolt.Determination of resistivity system described in the utility model, its relevant control circuit may utilize existing mature technology and realizes, mainly including the running voltage of control coil, measuring the current value receiving current sensor thus calculating resistivity value according to sample dimensions, determination of resistivity system and data handling system complete data storage, post processing by signal processor and central controller and show in real time.
Operation principle: make two ends nuts produce to put on the thrust of upper lower bearing steel plate with the carrying screw rod of anti-silk fine thread by rotating two ends, thus realizing lasting or variable axial tensile load applying as required, the faradic current changing ion moving system with load also constantly changes, the faradic current detected is delivered to signal processor by current sensor, and the voltage in ion moving system is by signal generator control；Signal processor is acquired and computational analysis by arranging the frequency data to signal generator and signal picker, and gathered data and result of calculation store in the central controller in real time, and are shown analysis result in real time by display.
The beneficial effects of the utility model are: this utility model is based on contactless impedance method, electromagnetic induction technology is used to realize the noncontact electrodeless mensuration concrete resistivity of salt water saturation, thus obtaining concrete interconnected pore rate according to theoretical formula method, breach the conventional test methodologies restriction to sample size, thus realizing the test to concrete sample interconnected pore rate, load is drawn by test specimen is applied axle, carry out the in-situ monitoring of concrete hole structure evolution process under load action, the relation of the concrete interconnected pore rate recorded and load and porosity more may be directly applied to concrete structure durability prediction.Assay device has that principle is clear, method is easy, finding speed is fast and the advantage such as good stability, can make up existing method and apparatus and can not meet concrete pore rate and measure the deficiency of concrete hole structure evolution in-situ monitoring technology under especially load action.
Accompanying drawing explanation
Fig. 1 is apparatus structure schematic diagram of the present utility model.
The ion moving system that Fig. 2 is this utility model test device launches schematic diagram.
Fig. 3 is the front view of flange platen of the present utility model.
Fig. 4 is the side view of flange platen of the present utility model.
Fig. 5 is the structure chart of liquid-feeding tube of the present utility model.
Fig. 6 is that axle draws concrete loading unit schematic diagram.
Fig. 7 is that axle draws concrete sample schematic diagram.
Fig. 8 is carrying screw rod and supporting nut schematic diagram.
Fig. 9 is upper bearing steel plate schematic diagram.
Figure 10 is lower bearing steel plate schematic diagram.
Detailed description of the invention
This utility model is further illustrated below in conjunction with accompanying drawing
With reference to accompanying drawing:
Embodiment 1
Load action concrete hole structure evolution in-situ monitoring device described in the utility model, including ion migration unit, resistance measurement unit, loading unit and data processing unit, described ion migration unit includes two with the flange platen 1 of through hole, liquid-feeding tube 7, fluid infusion tank 10 and Screw arbor with nut at both-ends 5, the corresponding flange platen 1 of each port of described liquid-feeding tube 7；The two-port of described liquid-feeding tube 7 is inserted in its through hole from corresponding flange platen 1 outer face respectively；Two flange platen inner faces relatively and form the test chamber for clamping test specimen 11 to be measured by Screw arbor with nut at both-ends 5, are sealed by rubber washer 4 between flange platen 1 and test specimen to be measured 11；Described fluid infusion tank 10 and described liquid-feeding tube 7 pipeline connection；
Described resistance measurement unit includes signal generator 28, coil 27, magnetic core 26 and current sensor 29, and described liquid-feeding tube 7 is affixed with corresponding flange platen 1 after sequentially passing through magnetic core 26 and current sensor 29；Described coil 27 is wrapped on described magnetic core 26, and the signal input part of described coil 27 two ends and described signal generator 28 is electrically connected；
Described loading unit include concrete axial draw test specimen 11, be loaded on concrete axial and draw the carrying steel plate (18,19) at test specimen two ends, tapped T-shaped built-in fitting 16, carrying screw rod 13 and load transducer 15, described concrete axial draws test specimen 11 to be provided with the reserved through hole 12 of axial arranging, described concrete axial draws test specimen 11 two ends pre-buried multiple T-shaped built-in fittings 16 respectively, and the thread segment of described T-shaped built-in fitting 16 points to concrete axial and draws test specimen 11 outside；Described carrying screw rod 13 runs through reserved through hole, and nut 14 is configured at described carrying screw rod two ends, carrying steel plate (18,19) it is furnished with outside described nut 14, the thread segment of described T-shaped built-in fitting 16 is spirally connected with fastening bolt 17, it is ensured that described carrying steel plate (18,19) and described concrete axial draw test specimen 11 end face to fit；Described load transducer 15 is arranged on described concrete axial and draws test specimen 11 sidewall, and the described signal output part of load transducer 15 and the signal picker of data processing unit are electrically connected；
Described data processing unit includes signal picker 30, signal processor 31 and central controller 32, the signal output part of the input of described signal picker 30 and described current sensor 29 is electrically connected, the signal output part of described signal generator, described signal picker outfan be electrically connected with the signal input part of described signal processor 31 respectively, the signal output part of described signal processor 31 is electrically connected with the corresponding port of described central controller 32.
Described liquid-feeding tube 7 is loop configuration；Described liquid-feeding tube 7 is provided with liquid flowing valve 8 and draining valve 9, and wherein said liquid flowing valve 8 is arranged on the line connection being connected with fluid infusion tank 10, and described draining valve 9 is arranged on the bottom of liquid-feeding tube 7；Described fluid infusion tank 10 is connected with described liquid-feeding tube by flexible pipe.
Described flange platen top is provided with passage 2, and wherein said passage 2 one end connects with described through hole, the other end and flange platen 1 ft connection.
Described liquid-feeding tube 7 adopts the bakelite of non-conductive class, polyurethane plastics, epoxy plastics, unsaturated polyester plastic, organic siliconresin or allyl resin class material to make.
The through hole of described flange platen 1 is stepped hole, and the through-hole diameter of the inner face of described flange platen 1 is more than the through-hole diameter of outer face, and described passage 2 wherein one end connects with the through hole of the inner face near described flange platen 1；Be spirally connected after the described bolt connecting hole 3 on split bolt 5 two ends traverse flange platen 1 two fastening nuts 6, and wherein said fastening nut 6 adopts aerofoil profile STAINLESS STEEL NUTS；The liquid-feeding tube 7 of described ion moving system fills the saline solution of concentration known, saline solution can be supplemented by fluid infusion tank 10, flange top is provided with passage 2, it is ensured that add that saltwater injection is smooth and easy and saline can be full of whole liquid-feeding tube 7 cross section, and after off-test, saline solution is discharged by draining valve 9.Test specimen to be measured is positioned between two flange platens 1, is sealed by rubber ring 4 between flange platen 1 and test specimen to be measured 11, with Screw arbor with nut at both-ends 5 mounting flange platen 1 and test specimen 11 to be measured.
Described rubber washer 4 is circular cross section along circumferential direction, the diameter of rubber washer 4 changes with flange platen 1 size, test specimen to be measured 11 net sectional area, test specimen 11 effective cross-section size range to be measured is the circular cross-section of diameter 50mm～150mm, that is the circular cross section that effective cross-section region is diameter 50mm～150mm that concrete test block ion to be measured passes through.
Described concrete axial draws the preformed hole 12 of test specimen 11, and geometric centroid in the axial direction stays and sets；Described concrete axial draws the two ends of test specimen 11, the reserved pit identical with nut size in preformed hole 12 position；Described concrete axial draws the two ends of test specimen 11 to leave outstanding flange, and the edge of a wing and concrete sample are with wide.
The described female T-shaped built-in fitting 16 of the pre-buried band in test specimen 11 two ends.
Described carrying steel plate geometric centroid place reserves circular hole 22, and with the faulting of slab ends 23 of certain depth around preformed hole 22, faulting of slab ends 23 area shape is identical with nut.
Described carrying screw rod 13 adopts corrosion resisting stainless steel, and screw diameter mates with concrete sample reserving hole channel 12, and close screw thread is carved with at screw rod 13 two ends, and screw rod two ends have the parallel surface being available for spanner clamping, and two ends hand of spiral is contrary.
Described carrying screw rod 13 and supporting nut 14 have auto-lock function, along a direction rotary screw, two ends nut can produce thrust, when rupturing suddenly occurs in test specimen, the nut 14 at screw rod two ends can pin divided into two parts concrete sample 11, it is to avoid test specimen suddenly rupture separate danger.
Described nut 14 can be placed in concrete groove and upper lower bearing steel plate faulting of slab ends 23, prevents nut 14 from rotating with screw rod during rotary screw 13.
Described upper bearing steel plate 18, lower bearing steel plate 19, fastening bolt 17 and T-shaped built-in fitting 16 can fastens as overall before casting concrete, the template used end mould of test specimen is drawn as casting concrete axle, can ensure that the accurate pre-buried location of T-shaped built-in fitting 16, upper lower bearing steel plate and fastening bolt 17 can Reusabilities.
Described load transducer 15 adopts punching sensor, and in order to reflect the size of load level, punching sensor is embedded in the circular hole 24 of upper bearing steel plate 18 by cover plate 20 and bolt 21.
Described determination of resistivity system, its relevant control circuit may utilize existing mature technology and realizes, mainly including the running voltage of control coil, measuring the current value receiving current sensor thus calculating resistivity value according to sample dimensions, determination of resistivity system and data handling system complete data storage, post processing by signal processor and central controller and show in real time.
Embodiment 2 load action described in the utility model concrete hole structure evolution in-situ monitoring method, comprises the following steps:
1) preparation of concrete test specimen to be measured:
The test of concrete hole structure evolution in-situ monitoring is damaged for load, build dumbbell shape test specimen, by test piece maintenance to setting age, it is dried to constant weight in an oven, then concrete sample to be measured is soaked in normal concentration saline solution or the full salt of vacuum is saturated to hole, the concentration of described standard chlorination sodium solution is 0.1～2mol/L, axle draws test specimen remove two opposition side other region epoxy resin extra-regional to be tested or paraffin seals；
2) preparation before measuring:
Normal concentration saline solution and step 1 is ensured before experiment) the full salt concrete sample to be measured temperature that obtains is identical, and two flange platens are sealed docking, and in liquid-feeding tube, perfusion normal saline solution is with calibrating instrument, and determines the electricalresistivityρ of normal concentration saline solution0；After demarcation terminates, drain normal saline solution, the full salt concrete sample to be measured installing loading unit is coated with a little vaseline to increase sealing with rubber seal contact position, then the liquid-feeding tube being connected to flange platen is sealed fastening with full salt concrete sample to be measured and become a sealing entirety, again in liquid-feeding tube, irrigate normal saline solution, selecting NaCl solution in test, the concentration of NaCl solution is 0.1～2mol/L；
3) electricalresistivityρ measures:
The sample frequency of data collecting system is set, data handling system automatically gathers faradic current and voltage from determination of resistivity system, calculation procedure calculates resistivity according to formula (1), and show change in resistance rate curve in real time, when change in resistance rate versus time curve is close to horizontal linear, resistivity value now is concrete test block resistivity under normal saline solution saturated conditions:
In formula, ρ is the resistivity (Ω m) of test specimen to be measured, and V is inductance loop voltage (V), I be inductance loop electric current (A), S is the effective cross-sectional area (m of test specimen to be measured2), L is the thickness (m) of test specimen to be measured；
Draw test specimen classification applying axle to draw load by countershaft, record the resistivity of load at different levels and correspondence thereof respectively；
4) porosity φ measures:
The relation of resistivity and porosity can be obtained, such as formula (2) according to Archie equation.Apply it to concrete interconnected pore to calculate, then calculated concrete interconnected pore rate φ by formula (2) again by the concrete resistivity value of mensuration:
In formula, ρ is concrete resistivity (Ω m), ρ0For the resistivity (Ω m) of normal concentration saline solution, φ is porosity, and α and m is fitting coefficient；
According to step 3) different resistivity that measures, calculate concrete interconnected pore rate corresponding under different load level respectively.
Embodiment 3 is below to measure the ratio of mud 0.53, match ratio for cement: water: sand: the concrete of coarse aggregate=1:0.53:2.0:3.0 is concrete interconnected pore rate in-situ monitoring under axial tension load action, and work of the present utility model is illustrated.
This concrete raw material of embodiment mixing is: cement is P.I525 class a portland cement, and sand adopts the fluvial sand of modulus of fineness 2.6, and coarse aggregate adopts the rubble (maximum particle diameter 25mm) of continuous grading, hydromining tap water.Building axle in Standard Module draws concrete sample effective cross-section to be of a size of 100mm × 100mm, the prominent length in the edge of a wing is 50mm, flange edges height 100mm, piece lengths 800mm, each pre-buried 8 T-shaped built-in fittings at concrete sample two ends, the preformed hole of the reserved diameter 26mm in test specimen center, builds after molding at fog room Plays maintenance 28d, then dries in an oven to constant weight.The axle being intended to load draws concrete sample 11 except a side, and the hot molten paraffin wax filling perforation of its excess-three side seals, and in the NaCl solution of 0.5mol/L, immersion makes concrete satisfy water.
Draw in the preformed hole 12 of concrete sample 11 through carrying screw rod 13 at axle, screw on nut 14 in screw rod two ends, two ends nut 14 is made to embed the pit at concrete sample two ends by rotary screw 13, upper bearing steel plate 18 and lower bearing steel plate 19 are installed, make nut 14 highlight concrete sample 11 and be partially submerged into the pit 23 of carrying steel plate, fastening bolt 17 is connected through the hole 25 carrying steel plate with T-shaped built-in fitting 16 to be tightened, it is ensured that 16, two ends fastening bolt 17 screw-down torque is identical.Punching load transducer 15 mounted package steel plate 20 are installed, tight a bolt 21.
Before experiment, the NaCl solution of the 0.5mol/L prepared and assay device, concrete sample are placed in the indoor environment of constant temperature, to ensure that temperature is consistent.
Liquid flowing valve 8 and draining valve 9 are closed, fluid infusion tank 10 irrigates the NaCl solution of the room temperature 0.5mol/L of 2/3 height of water level.Two flange platens 1 are docked, and adopts Screw arbor with nut at both-ends 5 and wing nut 6 clamp flange 1, make liquid-feeding tube 7 form a complete annular after flange platen 1 docks, guaranteed to seal by rubber ring 4 between flange platen 1.Open liquid flowing valve 8, make NaCl solution be filled up completely with liquid-feeding tube 7, till passage 2 will have NaCl solution to flow out, close rapidly liquid flowing valve 8.
Arranging test voltage by central controller 32 is 1V, and sample frequency is 1Hz, and the collection result of signal processor 31 is shown in real time by central controller 32, is determined the resistivity of this NaCl solution after data stabilization by following formula；
In formula, ρ is that the resistivity of test specimen to be measured is (here for pre-configured NaCl solution, concentration is 0.5mol/L), V is inductance loop voltage, I is inductance loop electric current, S is the effective cross-sectional area (here for liquid-feeding tube sectional area) of test specimen to be measured, and L is the thickness (here for pipe girth) of test specimen to be measured.
Calculate the electricalresistivityρ of the NaCl solution determining 0.5mol/L0It is 0.16462 Ω m (laboratory temperature is 20 DEG C).Sampling is stopped after record data, open the NaCl solution in draining valve 9 emptying liquid-feeding tube 7, unclamp wing nut 6, concrete sample 11 is coated with in the position of intended contact rubber ring 4 a little vaseline, increase sealing, concrete sample 11 is fixed between flange platen 1 according to Fig. 1.
Close draining valve 9, open liquid flowing valve 8 and make NaCl solution again irrigate all spaces between full liquid-feeding tube 7 and flange platen 1 and test specimen to be measured 11, close liquid flowing valve 8.Nut 14 is made to produce extrapolability by rotating carrying screw rod 13, reading according to load transducer 15 control axle draw load respectively 0,5kN, 10kN, 15kN, repeat the step of said determination resistivity, measure and adopt concrete electricalresistivityρ respectively 2.91525 Ω m, 2.79443 Ω m, 2.55125 Ω m, 2.27611 Ω m under same test specimen in-site detecting difference load level.
The relation of resistivity and porosity can be obtained according to Archie equation, calculate concrete interconnected pore rate according to following formula.
In formula, ρ is concrete resistivity, ρ0For the resistivity of normal concentration saline solution, φ is porosity, and α and m is fitting coefficient, and α takes 2, m and takes 1.3.
Calculating the interconnected pore rate of concrete sample under 4 kinds of load levels according to above formula is 18.7%, 19.3%, 20.7% and 22.6%.
After off-test, first open draining valve 9, after the solution in ring-shaped round pipe 7 all drains, take off test specimen 11 to be measured.
When implementing, concrete device model is not limited by this utility model, as long as the components and parts of above-mentioned functions can be completed.
Content described in this specification embodiment is only enumerating of the way of realization to utility model design; protection domain of the present utility model is not construed as being only limitted to the concrete form that embodiment is stated, protection domain of the present utility model also include those skilled in the art according to this utility model design it is conceivable that equivalent technologies means.
Claims (10)
1. load action concrete hole structure evolution in-situ monitoring device, it is characterized in that: include ion migration unit, resistance measurement unit, loading unit and data processing unit, described ion migration unit includes two with the flange platen of through hole, liquid-feeding tube, fluid infusion tank and Screw arbor with nut at both-ends, the corresponding flange platen of each port of described liquid-feeding tube；The two-port of described liquid-feeding tube is inserted in its through hole from corresponding flange platen outer face respectively；Two flange platen inner faces relatively and form the test chamber for clamping test specimen to be measured by Screw arbor with nut at both-ends, by rubber ring seal between flange platen and test specimen to be measured；Described fluid infusion tank and described liquid-feeding tube pipeline connection；
Described resistance measurement unit includes signal generator, coil, magnetic core and current sensor, and described liquid-feeding tube is affixed with corresponding flange platen after sequentially passing through magnetic core and current sensor；Described coil is wrapped on described magnetic core, and the signal input part of described coil two ends and described signal generator is electrically connected；
Described loading unit include concrete axial draw test specimen, be loaded on concrete axial and draw the carrying steel plate at test specimen two ends, tapped T-shaped built-in fitting, carrying screw rod and load transducer, described concrete axial draws test specimen to be provided with the reserved through hole of axial arranging, described concrete axial draws test specimen two ends pre-buried multiple T-shaped built-in fittings respectively, and the thread segment of described T-shaped built-in fitting points to concrete axial and draws outside test specimen；Described carrying screw rod runs through reserved through hole, and nut is configured at described carrying screw rod two ends, described nut side is furnished with carrying steel plate, and the thread segment of described T-shaped built-in fitting is spirally connected with fastening bolt, it is ensured that described carrying steel plate draws test specimen end face to fit with described concrete axial；Described load transducer is arranged on described concrete axial and draws test specimen sidewall, and the signal output part of described load transducer and the signal picker of data processing unit are electrically connected；
Described data processing unit includes signal picker, signal processor and central controller, the signal output part of the input of described signal picker and described current sensor is electrically connected, the signal output part of described signal generator, described signal picker outfan be electrically connected with the signal input part of described signal processor respectively, the signal output part of described signal processor is electrically connected with the corresponding port of described central controller.
2. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 1, it is characterised in that: liquid-feeding tube is loop configuration；Liquid-feeding tube is provided with liquid flowing valve and draining valve, and wherein said liquid flowing valve is arranged on the line connection being connected with fluid infusion tank, and described draining valve is arranged on the bottom of liquid-feeding tube；Fluid infusion tank is connected with described liquid-feeding tube by flexible pipe.
3. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 1, it is characterised in that: flange platen top is provided with passage, and wherein said passage one end connects with described through hole, the other end and flange platen ft connection.
4. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 2, it is characterised in that: liquid-feeding tube adopts the bakelite of non-conductive class, polyurethane plastics, epoxy plastics, unsaturated polyester plastic, organic siliconresin or allyl resin class material to make.
5. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 3, it is characterized in that: the through hole of flange platen is stepped hole, and the through-hole diameter of the inner face of described flange platen is more than the through-hole diameter of outer face, and described passage wherein one end connects with the through hole of the inner face near described flange platen.
6. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 5, it is characterized in that: be spirally connected after the bolt connecting hole on split bolt two ends traverse flange platen two fastening nuts, and wherein said fastening nut adopts aerofoil profile STAINLESS STEEL NUTS.
7. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 1, it is characterized in that: described concrete axial draws the reserved through hole of test specimen to be arranged on concrete axial and draws the geometric centroid place of test specimen, and keeps the central shaft of reserved through hole to overlap with the central shaft of concrete axial tensile test specimen.
8. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 7, it is characterised in that: described concrete axial draws the two ends of test specimen to be provided with the pit coaxial with reserved through hole, and the size of pit is mated with nut；Described concrete axial draws the two ends of test specimen to leave outstanding flange, and the edge of a wing and concrete sample are with wide.
9. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 8, it is characterized in that: described carrying steel plate is arranged installs through hole and the reserved circular hole corresponding with reserved through hole one to one with fastening bolt, wherein said reserved circular hole is arranged on the geometric centroid place of carrying steel plate, and reserved circular is round the faulting of slab ends mated with nut；Described nut is placed in concrete pit and carrying steel plate faulting of slab ends；The screw diameter of described carrying screw rod mates with reserved through hole, and screw rod two ends are with external screw thread, and screw rod two ends have the parallel surface for spanner clamping, and two ends hand of spiral is contrary, and described carrying screw rod forms self-locking structure with described nut.
10. load action concrete hole structure evolution in-situ monitoring device as claimed in claim 8, it is characterised in that: described load transducer adopts foil gauge, amesdial or displacement transducer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520976840.1U CN205374240U (en) | 2015-12-01 | 2015-12-01 | Loading concrete pore structure evolution normal position monitoring devices |
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| CN201520976840.1U CN205374240U (en) | 2015-12-01 | 2015-12-01 | Loading concrete pore structure evolution normal position monitoring devices |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105466833A (en) * | 2015-12-01 | 2016-04-06 | 浙江工业大学 | In-situ monitoring method for concrete pore structure evolution under load effect and testing device |
| CN115753520A (en) * | 2023-01-10 | 2023-03-07 | 昆明理工大学 | Spherical penetration radius determination method for tortuosity of water action rock-soil mass in power law slurry |
-
2015
- 2015-12-01 CN CN201520976840.1U patent/CN205374240U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105466833A (en) * | 2015-12-01 | 2016-04-06 | 浙江工业大学 | In-situ monitoring method for concrete pore structure evolution under load effect and testing device |
| CN105466833B (en) * | 2015-12-01 | 2018-05-08 | 浙江工业大学 | Load action concrete hole structure evolution in-situ monitoring method and experimental rig |
| CN115753520A (en) * | 2023-01-10 | 2023-03-07 | 昆明理工大学 | Spherical penetration radius determination method for tortuosity of water action rock-soil mass in power law slurry |
| CN115753520B (en) * | 2023-01-10 | 2023-05-02 | 昆明理工大学 | Spherical penetration radius determination method for tortuosity of water-acting rock-soil body during power law slurry |
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