JP4313373B2 - How to determine the working time of adhesive - Google Patents

Description

  The present invention relates to a method for determining the usable time of an adhesive, and more particularly to a method for determining the usable time of an adhesive applied to a simulated steel deck.

  In steel floor slabs with goose asphalt pavement under heavy traffic, local deformation occurs near the steel floor slab and the U-rib weld due to the low rigidity of goose asphalt, and this behavior causes member joints In particular, this phenomenon becomes prominent in summer when the goose asphalt softens and the rigidity decreases.

  Therefore, it has been clarified that the steel floor slab with goose asphalt pavement has a problem in service unless the emergency repair such as the installation work of the reinforcing plate is frequently performed in the cracked part due to fatigue. In addition, emergency repairs such as installation work for reinforcing plates require nighttime traffic closure or traffic regulation such as one-side lane regulation at each construction, and traffic congestion on main roads leads to traffic congestion. It has become.

  Permanent countermeasures include increasing the thickness of the upper surface of the steel deck, improving the accuracy of the welding finish considering fatigue design, and integrating the steel deck with steel fiber reinforced concrete. However, measures such as increasing the thickness of the upper surface of the steel slab and improving the accuracy of the welding finish considering fatigue design are not available for steel slabs where the U-rib material is welded under the upper surface of the steel slab. In that case, it cannot be adopted.

  On the other hand, the integration with the steel floor slab by steel fiber reinforced concrete is to integrate concrete with a large rigidity and a large deformation suppressing effect instead of goose asphalt on the upper surface of the steel floor slab with an adhesive and a diver. It can be said that this is an effective repair method that can be applied to steel slabs in service. However, steel slabs in service are subject to the time required for repair work to avoid traffic congestion. For this reason, it is necessary to use super-hard hard concrete having a markedly faster curing speed than ordinary concrete in combination with a resin-based adhesive having a similarly fast curing speed.

  Reinforcement effect of steel floor slab with steel fiber reinforced super fast hard concrete is the first time that steel fiber reinforced super fast hard concrete, which is driven in place of steel floor slab and goose asphalt, is integrated with an adhesive and a diver. Is demonstrated.

  The gibber is a bolt-shaped projection welded to the upper surface of the steel deck, and integration is achieved by the shear resistance force due to the shape of the projection and the adhesion strength between the steel fiber reinforced super fast hard concrete and the gibber. Therefore, the reinforcing effect depends on the weld strength of the gibber and the bond strength between the steel fiber reinforced ultrafast concrete and the gibber.

  The welding strength of the gibber is secured by an automatic welding system. Moreover, since the adhesion strength between the steel fiber reinforced super-hard-hardened concrete and the gibber has a close relationship with the compressive strength, it is ensured by ensuring the compressive strength of the predetermined steel fiber-reinforced super-hard hard concrete. That is, the integrated reinforcing effect by the gibber can be obtained almost stably by securing the compressive strength of the above automatic welding system and the steel fiber reinforced ultrafast concrete.

  However, the adhesive strength between steel slab and steel fiber reinforced super hard-hardened concrete due to the adhesive depends on the condition of the top surface of the steel slab, the interaction between the material properties of the adhesive and steel fiber reinforced super-hard concrete, or temperature and humidity Since it is very sensitive to the influence of environmental conditions, it is necessary to measure and confirm using test specimens that reproduce the field conditions in advance.

In contrast, in the following Patent Document 1, the present applicant has proposed an adhesion test method for measuring the adhesion strength between a steel floor slab and concrete using an adhesive, and an adhesion test tool used therefor.
In this adhesion test method, a simulated steel floor slab is used, a plurality of concrete blocks as test specimens are individually driven on the simulated steel floor slab, and the adhesion strength of the concrete block is measured after a predetermined age. is there.
Japanese Patent Application No. 2005-128992 (application date: April 27, 2005, priority date: March 31, 2005)

Such an adhesion test method can be applied as a preliminary examination in a test room, but it is difficult to apply to each construction site, and the practicality is difficult from the viewpoint of proficiency in testing. .
In addition, when this adhesion test was carried out by changing the time over which the steel fiber reinforced ultrafast concrete was stacked after application of the adhesive to several levels or more, the usable time of the adhesive (mixing the adhesive) From the viewpoint of work man-hours, the practicality is extremely poor. That is, in the method disclosed in Patent Document 1, the steel plate and the steel fiber reinforced super fast hard concrete have a usable time of an adhesive necessary to ensure a predetermined adhesion strength, for example, 1 N / mm ² or more. It was impossible to make a simple determination.

  The present invention has been made to solve the above-described problems, and is intended to provide a method for determining the usable life of an adhesive that can be applied at a construction site and has sufficient accuracy. Moreover, it relates to an adhesive used for concrete paving such as steel fiber reinforced super fast hard concrete (SFRC) for a steel floor slab, and provides a method for determining the usable time of an adhesive that can be used particularly effectively.

  As a result of intensive research, the present inventors have applied a resin adhesive to a simulated steel floor slab, and if the adhesive has tack (sticking), attention is paid to the adhesive and concrete adhering to each other. And if the property can be quantified and evaluated, it has been found that the usable time of the adhesive can be easily determined. This eliminates the need for the complicated work of applying a resin-based adhesive, driving concrete at a fixed interval after application, and measuring the adhesion strength, and determining the time for placing concrete. .

The invention according to claim 1 is an adhesive application step of applying an adhesive onto a polished simulated steel slab, and immediately after the application step, the specimen A is applied to the simulated steel slab with an adhesive. The first test body arranging step to be arranged on the top, and after the elapse of a predetermined time t from the application step, the other test body B having the same shape and material as the test body A is applied with the adhesive. A second test specimen placement step to be placed on the steel slab, and then a peeling force measurement step of peeling the test specimens A and B from the simulated steel slab and measuring a peeling force at the time of the peeling; A change in the difference between the peeling force of the specimen A and the peeling force of the specimen B is calculated with respect to the change in the time t, and the predetermined time t _max when the difference exceeds a predetermined magnitude is obtained. pot life of the adhesive and having a pot life calculation step of time t _max and pot life of the adhesive A constant way.
Note that “immediately after” in the present invention does not only mean that the absolute time is short, but the total time required to determine the usable time of the adhesive such as the predetermined time t. In comparison, it includes the meaning of a relatively short time.

  The invention according to claim 2 is characterized in that, in the method for determining the usable time of the adhesive according to claim 1, the time for performing the measurement step is immediately after the specimen B is arranged.

  According to a third aspect of the present invention, in the method for determining the usable time of the adhesive according to the first or second aspect, in the first specimen arrangement step, the number of times the peeling force is measured with respect to the change of the predetermined time t is measured. A corresponding number of specimens A are arranged, and in the second specimen arrangement process, specimens B are sequentially arranged every time a predetermined time t to be measured elapses.

  In the invention according to claim 4, in the method for determining the usable time of the adhesive according to any one of claims 1 to 3, a plurality of each of the test bodies A and B are arranged for one predetermined time t, An average value of exfoliation force values of a plurality of test bodies measured for the test bodies A and B is calculated, and the difference is calculated using the average value.

  According to a fifth aspect of the present invention, in the method for determining the usable life of the adhesive according to any one of the first to fourth aspects, the test body is a nut.

  In the invention according to claim 6, in the method for determining the usable life of the adhesive according to any one of claims 1 to 5, the adhesive is an adhesive used for concrete paving of a steel slab. Features.

  According to the first aspect of the present invention, the adhesive is applied on the simulated steel slab that has been polished, and the specimens A and B are installed with a predetermined time difference, and the difference in the peeling force between the two is a predetermined magnitude. In order to determine the usable time of the adhesive from the predetermined time when it exceeds the limit, it is easy to apply at the construction site and provides a simple and sufficient accuracy method for determining the usable time of the adhesive can do.

  According to the invention according to claim 2, when the test step is performed immediately after the test body B is arranged, the peeling force of the test body in a state where a predetermined time has elapsed from the application of the adhesive, that is, the adhesive It becomes possible to measure the adhesion strength. In particular, since the peeling is performed immediately after placing the test body B, it is possible to measure the state of adhesion of the adhesive, so-called tack, and to measure the adhesive adhesion more accurately. It becomes.

  According to the invention according to claim 3, in the first specimen arrangement step, the number of specimens A corresponding to the number of times of measurement of the peeling force with respect to the change of the predetermined time t is arranged, and in the second specimen arrangement step, Since the test body B is sequentially arranged every time the predetermined time t to be measured elapses, it becomes possible to simultaneously measure the peeling force with respect to a plurality of changes in the predetermined time, thereby simplifying the usable time of the adhesive. And it becomes possible to determine efficiently.

  According to the invention of claim 4, a plurality of test specimens A and B are arranged for one predetermined time t, and the average of the peeling force values of the plurality of test specimens measured for each test specimen A and B Since the value is calculated and the difference is calculated using the average value, it is possible to measure the peeling force with higher accuracy and to increase the accuracy of the usable time of the adhesive.

  According to the invention of claim 5, since the test body is a nut, a test for determining the usable life of the adhesive can be performed more easily and inexpensively.

  According to the invention of claim 6, since the adhesive is an adhesive used for concrete pavement of a steel floor slab, it is used for concrete pavement such as steel fiber reinforced super fast hard concrete (SFRC) for an actual steel floor slab. With respect to the adhesive, it is possible to easily and accurately determine the usable time of the adhesive.

Hereinafter, the method for determining the usable time of the adhesive according to the present invention will be described in detail.
In the present invention, “the usable time of the adhesive” means that the adhesive is used to bond the members to be joined after the adhesive is applied in order to secure an appropriate joining state when joining the various members using the adhesive. In particular, when concrete is driven into the steel slab, the maximum time that the concrete can be driven after mixing and applying the adhesive to the steel slab is specified. means.

The tool used for the method for determining the usable life of the adhesive of the present invention will be described.
FIG. 1 shows a simulated steel slab container 1 used in the method for determining the usable life of an adhesive according to the present invention. Reference numeral 2 denotes a bottom plate of the container, which is a simulated steel slab made of the same material as the steel slab actually used. Reference numeral 3 denotes a side plate, which plays a role of preventing the adhesive applied on the simulated steel deck 2 from flowing out. Reference numeral 4 denotes a handle for facilitating carrying the simulated steel slab container 1. As shown in Patent Document 1, the structure of the simulated steel floor slab container is such that the bottom plate and the side plate are detachable, a frame is provided on the top surface of the bottom plate instead of the side plate, or the periphery of the bottom plate is inclined upward By providing the inclined surface, it is possible to prevent the adhesive from flowing out of the bottom plate.

  FIG. 2 shows a nut 10 serving as a test body. When measuring the peeling force, an eyebolt having a bolt portion 13 having the same diameter is screwed into the screw hole 11 of the nut 10. The test body is not limited to a nut, but by using a nut, a general-purpose product can be used at a low cost and a test can be performed very efficiently. In addition, in the tests using nuts, the “Nut Tensile Test” proposed by the Resin Pavement Technology Association has judged whether or not traffic can be released after the construction of resin-type non-slip pavements, and has a lot of results. It is also a highly reliable test method.

Next, the procedure of the method for determining the usable life of the adhesive according to the present invention will be described.
FIG. 3 is a diagram illustrating a procedure of the determination method.
(1) Adhesive application process Adhesion for measuring the pot life as shown in FIG. 3 (b) on the bottom surface of the simulated steel deck slab container 1 (FIG. 3 (a)). Agent 20 is applied.
(2) First Specimen Placement Step Immediately after the application step (1) above, as shown in FIG. 3 (c), the test specimen A (reference numeral 10 (A)) is a simulated steel floor coated with an adhesive. Place on the plate. The nut shown in FIG. 2 is used for the test body.

(3) Second Specimen Arranging Step After a predetermined time t has elapsed from the coating step (1), another specimen B (reference numeral 10 (B)) configured with the same shape and material as the specimen A is used. As shown in FIG.3 (d), it arrange | positions on the simulation steel deck which apply | coated the adhesive agent.

(4) Exfoliation force measurement process Immediately after the second specimen arrangement step (3) above, the specimens A and B are exfoliated from the simulated steel deck and the exfoliation force at the exfoliation is measured. At the time of peeling, when the eyebolt 12 shown in FIG. Measure the maximum exfoliation force.

In order to measure the change in the peeling force of the specimen with respect to the change in the predetermined time t described above, the steps (1) to (4) are repeated a plurality of times while changing the predetermined time t.
However, in order to increase the efficiency of measurement, in the above (2) first specimen arrangement step, a predetermined number of specimens A corresponding to the number of measurement times of the peeling force with respect to a change in the predetermined time t are arranged and measured. It is preferable to repeat the above (3) second specimen arrangement step and (4) exfoliation force measurement step each time the time t elapses. The timing of arranging the test body B may be sequentially arranged every predetermined time such as 10 minutes or 15 minutes, or only in the time zone to be measured in a finer time, the time interval of the test body placement is shortened, In other cases, the time interval can be coarsened.

  Further, in order to increase the reliability of the measurement value of the peeling force, a plurality of test specimens A and B are arranged for one predetermined time t, and a plurality of test specimens measured for each of the test specimens A and B are concerned. It is also possible to calculate an average value of the exfoliation force values and use the average value as the exfoliation force for the predetermined time t.

(5) Usable time calculation step The difference between the peeling force of the specimen A measured in the above (4) and the peeling force of the specimen B is calculated, and the peeling force of the specimen A against the change of the predetermined time t and the specimen. A change in difference from the exfoliation force of B is obtained.
4 (a) is a graph showing a change in the exfoliation force P _B exfoliation force P _A and specimen B of the specimen A with respect to a change in a given time t. FIG. 4B shows the difference in exfoliation force (ΔP = P _A −P _B ).

Difference ΔP abrading force asked for a predetermined time t _max of the time exceeds a predetermined magnitude P _0, the pot life of the adhesive said predetermined constant-time t _max.
For P _{0, an} appropriate value is set depending on the type of adhesive and the use of the adhesive. For example, in an adhesive used for steel floor slab concrete pavement, zinc having an inner diameter of 6 mm and an outer diameter of 10.5 mm is used. When using a plated nut, ΔP is set to about 2 to 3N.

  According to the method for determining the usable time of the adhesive described above, the usable time of the adhesive can be easily determined. However, in actual construction, it is also important to measure the timing of traffic release after construction. For this reason, since it is troublesome to use another device, it is also possible to determine the appropriateness of traffic opening using the tool used in the method for determining the usable time of the adhesive as it is.

(Judgment method of traffic openness)
(1) Adhesive application process The adhesive used by the steel floor slab concrete pavement is applied to the bottom surface of the simulated steel floor slab container 1 in FIG.
(2) Specimen Arrangement Step Immediately after the application step (1) above, a nut as a test piece is placed on a simulated steel deck slab coated with an adhesive. The number of test specimens to be placed should be sufficient to determine the time when traffic can be opened.

(3) Stripping force measuring step After a predetermined time t has elapsed from the coating step (1) above, the test specimen is stripped from the simulated steel deck and the stripping force at the stripping is measured. At the time of exfoliation, the maximum exfoliation force at the time of exfoliation of the nut as the test body is measured using the eyebolt shown in FIG. 2 or the suspension scale 30 shown in FIG.

In order to measure the change in the peeling force of the test body with respect to the change in the predetermined time t described above, the test body is peeled off every time the predetermined time to be measured elapses.
In addition, in order to improve the reliability of the measurement value of the peeling force, a plurality of test specimens are arranged for one predetermined time t, and the average value of the peeling force values for the plurality of test specimens for the predetermined time t. And the average value can be used as the peeling force for the predetermined time t.

(4) Step of evaluating whether or not traffic is open From the graph of the change in the peel force of the test specimen with respect to the change in the predetermined time t measured in (3) above, a predetermined peel force P ₁ (for example, see FIG. 7; see P in FIG. 7). The case of ₁ = 8160 gf is indicated by a dotted line.) A time t _min indicating a greater exfoliation force is obtained, and the time after the time t _min is evaluated as being openable.
However, since the peeling force differs between the nut peeling force used for the specimen and the concrete actually used, the correlation between the peeling strength of the specimen and the peeling strength of the concrete is obtained, and the above prescribed peeling force is set. There is a need to. For example, when a galvanized nut having an inner diameter of 6 mm and an outer diameter of 10.5 mm is used as a test body, when the peeling force of the nut is 80 N or more, the adhesive strength of concrete in the Kenken type tensile test It has been confirmed that 0 N / mm ² or more is secured.

Further, from the correlation between the test result of the method for determining whether or not the traffic is open and the adhesion strength test result of the actual steel floor slab concrete pavement, for example, at a time t _min determined by the evaluation of whether or not the traffic is open, a predetermined coefficient It is also possible to determine the time when the traffic can be opened by multiplying.

  Next, using the examples, the method for determining the usable time of the adhesive of the present invention effectively measures the usable time of the adhesive, and the method for determining whether or not the above-mentioned traffic is open is a steel floor. Explain that it can also be used effectively in slab concrete pavement.

(Determining how long the adhesive can be used)
The temperature condition is 30 ° C., and an epoxy adhesive (product name: E200, manufactured by Konishi Co., Ltd.) is applied to the entire surface of the simulated steel floor slab with a film thickness of 1.0 mm. A plurality of 10.5 mm galvanized nuts are installed so as to be embedded in the adhesive at intervals of about 3 cm (intervals that are not affected when the adjacent nuts are pulled up).
Next, every time a predetermined time elapses from the application of the adhesive, the same nut as the specimen B is embedded in the adhesive. The timing for embedding the specimen B is 10 minutes.

Immediately after embedding specimen B, screw eyebolts into specimen A and specimen B so as not to disturb the adhesive, and remove the nut from the steel slab using a lifting scale (hand scale or push-pull gauge). Peel off and read the peeling force at that time.
The number of test specimens in each test time is three for each of the test specimens A and B, the average value of the peeling force relating to the three test specimens is calculated, and the value is the test specimen A for that time. And B exfoliation force.

FIG. 5 shows the change over time of the peeling force of the specimens A and B measured by the above test.
Furthermore, the difference of the peeling force of the test body A and the test body B is shown in FIG.
In the present invention, the range in which the difference in exfoliation force in FIG. 6 is a predetermined value or less is determined as the pot life, and for example, the range within 2 to 3 N (about 200 to 300 gf) is within the range of the adhesive. In the case of determining the pot life, the pot life is 110 minutes from the graph of FIG.

Next, in order to evaluate the validity of the method for determining the usable time of the adhesive, a Kenken-type tensile test was performed by the method described in Patent Document 1.
(1) A predetermined amount (coated film thickness: 1.0 mm) of the same adhesive was applied to a simulated steel slab that had been cleaned, and after application, vinyl chloride tubes (φ100 mm) were installed in a staggered manner.
(2) Concrete was poured into the vinyl chloride pipe after 20, 40, 60 and 120 minutes after application of the adhesive.
(3) A jig for tensile test was bonded after the concrete was cured, and the adhesion strength was measured using a Kenken-type tensile tester 3 hours after placing the concrete.

In the Kenken-type tensile test, except for the case where the concrete was driven 120 minutes after applying the adhesive was 0.01 N / mm ² , the other concrete showed an adhesive strength of about 1.1 N / mm ² , It was confirmed that the adhesive force was 1.0 N / mm ² or more. Thus, it was found that sufficient adhesive force was exhibited at least within the time determined by the method for determining the usable time according to the present invention.

(Judgment method of traffic openness)
The temperature condition was 30 ° C., and an epoxy adhesive (product name: E200W, manufactured by Konishi Co., Ltd.) was applied to the entire surface of the simulated steel floor slab with a film thickness of 1.0 mm, and the inner diameter was 6 mm and the outer diameter was 10 mm. A plurality of 5 mm galvanized nuts are installed so as to be embedded in the adhesive at intervals of about 3 cm (intervals that are not affected when the adjacent nuts are pulled up).

Next, every time a predetermined time elapses from the application of the adhesive (15 to 20 minutes), the eyebolt is screwed into the specimen so that the adhesive is not disturbed, and a suspension scale (hand scale or push-pull gauge). Peel off the nut from the steel slab using, and read the exfoliation force at that time.
The number of test specimens in each test time is three, and the average value of the exfoliation force relating to the three test specimens is calculated, and that value is taken as the exfoliation force of the test specimen for that time.

Moreover, it tested similarly to the method mentioned above except the coating-film thickness of the adhesive agent having been 0.5 mm. FIG. 7 shows the change over time of the peeling force of the test specimen measured from the two test results.
In the present invention, it can be determined that the traffic can be released if the exfoliation force is equal to or greater than a predetermined value. In the graph of FIG. 7, it can be determined that the traffic can be released if it is 80 N (8160 gf) or more. Accordingly, it is determined that the traffic can be opened after about 85 minutes after application of the adhesive when the coating thickness is 1.0 mm, and after about 110 minutes when the thickness is 0.5 mm.

  From the above description, according to the present invention, it is possible to provide a method for determining the usable time of an adhesive that can be applied at a construction site and has a simple and sufficient accuracy. Moreover, regarding the adhesive used for concrete pavement such as steel fiber reinforced super fast hard concrete (SFRC) for the steel deck, it is possible to provide a method for determining the usable time of the adhesive that can be used particularly effectively.

It is a perspective view of the simulated steel deck slab container used for the method for determining the usable time of the adhesive of the present invention. It is a figure explaining the test body etc. which are used for the working time determination method of the adhesive agent of this invention. It is a figure which shows the procedure of the working time determination method of the adhesive agent of this invention. It is a graph which shows the change of the peeling force of the test bodies A and B with respect to progress of the predetermined time after adhesive application, and the difference of those peeling forces. It is an Example which concerns on the working time determination method of an adhesive agent, and is a graph which shows the change of the peeling force of the test bodies A and B. FIG. It is an Example which concerns on the working time determination method of an adhesive agent, and is a graph which shows the change of the difference of the peeling force of the test bodies A and B. FIG. It is a graph which shows the change of the peeling force of a test body with progress of the predetermined time after adhesive agent application.

Explanation of symbols

1 Simulated steel slab container 2 Simulated steel slab (bottom plate)
3 Side plate 4 Holding means 10 Nut 11 Screw hole 12 Eye bolt 13 Bolt part 20 Adhesive 30 Suspension scale

Claims (6)

An adhesive application process for applying an adhesive on a simulated steel floor slab that has been cleaned;
Immediately after the application step, a first test body placement step of placing the test body A on the simulated steel slab coated with an adhesive;
Second specimen arrangement in which another specimen B having the same shape and material as specimen A is placed on the simulated steel slab coated with adhesive after a predetermined time t has elapsed from the coating step. Process,
Thereafter, the test specimens A and B are exfoliated from the simulated steel slab, and the exfoliation force measuring step for measuring exfoliation force at the exfoliation,
A change in the difference between the peeling force of the specimen A and the peeling force of the specimen B with respect to the change of the predetermined time t is calculated, and the predetermined time t _max when the difference exceeds a predetermined magnitude is obtained; A method for determining the usable time of the adhesive, comprising: a usable time calculating step in which the predetermined time t _max is used as the usable time of the adhesive.   The method for determining the usable time of an adhesive according to claim 1, wherein the measurement step is performed immediately after the specimen B is arranged.   3. The method for determining the usable life of an adhesive according to claim 1 or 2, wherein, in the first specimen arrangement step, a number of specimens A corresponding to the number of times of measurement of the peeling force with respect to the change in the predetermined time t are obtained. A method for determining the usable life of an adhesive, characterized in that, in the second test specimen arranging step, the specimen B is sequentially arranged every time a predetermined time t to be measured elapses.   In the method for determining the usable time of an adhesive according to any one of claims 1 to 3, a plurality of test specimens A and B are arranged for one predetermined time t, and the test specimens A and B are measured. A method for determining the usable time of an adhesive, comprising: calculating an average value of exfoliation forces relating to a plurality of test specimens, and calculating the difference using the average value.   5. The method for determining the usable life of an adhesive according to claim 1, wherein the test body is a nut. 6. The method for determining the usable life of an adhesive according to claim 1, wherein the adhesive is an adhesive used for concrete paving of a steel deck. Time determination method.

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