JP3881357B2 - Durability evaluation method and durability evaluation apparatus for roof base material - Google Patents

Description

  The present invention relates to a method and an apparatus for evaluating the durability of a roof base material used for a roof of a building such as a house.

  When constructing a roof of a building, a roof base material is laid on a field board or the like, and a tile material is spread on the roof base material. As the roof base material, a sheet material in which paper or fiber sheet is impregnated with asphalt is often used.

The test method for roof base material is stipulated in JIS standard, but it is necessary to reproduce the secular change in order to evaluate the durability of the roof base material, and JIS A 6005 reproduces such a secular change. There is no test method (see Non-Patent Document 1).
JIS K 6257 “Asphalt roofing felt” 1991, published by the Japanese Standards Association

  In recent years, attention has been focused on the service life of houses, and it is necessary to set a maintenance time in advance before building. Therefore, it is necessary to clarify the service life of the roof base material, and a method for evaluating the durability of the roof base material by reproducing the secular change is required. Here, there is JIS K 6257 “Vulcanized rubber and thermoplastic rubber-How to obtain heat aging characteristics” as a test method for the thermal deterioration characteristics of rubber used as a material for the roof base material. Since the result is different from the change in deterioration, there is a need for a method for reproducing and evaluating the aging deterioration of the durability of the roof base material.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a durability evaluation method for a roof base material capable of reproducing and evaluating the durability of the roof base material over time. It is.

The durability evaluation method for a roof base material according to claim 1 of the present invention includes a step of measuring a mechanical strength characteristic value in an initial state of the roof base material , and an acid inside the frame provided on the surface of the roof base material. After supplying the aqueous solution and supplying the acid aqueous solution to the surface of the roof base material at a predetermined liquid level, the acid aqueous solution supplied to the surface of the roof base material is evaporated and dried by heating it for a predetermined time. The process is defined as one cycle, the predetermined cycle is repeated, the mechanical strength characteristic value of the roof base material after repeating the predetermined cycle, the mechanical strength measurement value in the initial state, and the predetermined cycle are repeated. And a step of obtaining a ratio with the measured mechanical strength value after the measurement.

  The invention of claim 2 is characterized in that, in claim 1, the acid aqueous solution has a pH of 2 to 4, and the heating temperature for drying the acid aqueous solution is 50 to 90 ° C.

  The invention of claim 3 is characterized in that, in claim 1 or 2, the acid aqueous solution is an aqueous solution of sulfuric acid or nitric acid.

Further, the invention of claim 4 is any one of claims 1 to 3, wherein the amount of the aqueous acid solution supplied to the roof base material is 0.2 to 1.0 ml per 1 cm ² of the surface of the roof base material in each cycle. It is characterized by being.

The roof base material durability evaluation apparatus according to claim 5 of the present invention is a measuring means for measuring the mechanical strength characteristic value of the roof base material, and the mechanical strength in the initial state of the roof base material measured by the measuring means. Storage means, and an acid aqueous solution is introduced into the frame provided on the surface of the roof base material, and the acid aqueous solution is supplied to the surface of the roof base material at a predetermined liquid level. The process of evaporating and drying the acid aqueous solution supplied to the surface of the roof base material by heating is one cycle, the processing means for repeating the predetermined cycle, and the roof base measured by the measuring means after repeating the predetermined cycle by the processing means It has an operation means for obtaining a ratio between a mechanical strength characteristic value of the material and an initial mechanical strength measurement value stored in the storage means.

  According to the first aspect of the present invention, by causing the acid aqueous solution and heat to act on the surface of the roof base material, it is possible to reproduce the deterioration close to the secular change in actual use, and the measured mechanical The durability of the roof base material can be evaluated by reproducing the secular change from the strength characteristics.

  Further, as in the invention of claim 2, by setting the pH of the acid aqueous solution and the heating temperature for drying the acid aqueous solution, it becomes easy to reproduce the deterioration close to the secular change in actual use. .

  Further, as in the invention of claim 3, by selecting an acid of the acid aqueous solution, it becomes easy to reproduce deterioration close to secular change during actual use.

  Further, as in the invention of claim 4, by setting the supply amount of the acid aqueous solution, it becomes easy to reproduce the deterioration close to the secular change in actual use.

  Moreover, according to the durability evaluation apparatus of Claim 5, it becomes possible to automate the measurement of the durability of the roof base material.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The roof base material is generally formed into a sheet by impregnating a core material such as paper or fiber with a filler such as asphalt. Although it is possible to accelerate the deterioration of the filler by applying heat and moisture to the roof base material, the deterioration of the core material hardly progresses, so the overall deterioration state is significantly different from the deterioration state in actual use. It is difficult to evaluate the durability of the roof base material by such a method. Therefore, in the present invention, by repeatedly applying an acid aqueous solution to the surface of the roof base material and drying it, the deterioration of the filler and the core material can be simultaneously promoted, and the deterioration of the secular change close to the deterioration of actual use can be reproduced. It is what I did.

  In evaluating the durability of the roof base material, the roof base material to be evaluated is first cut into a size that is easy to handle. Usually, it is preferable to cut into a size of 100 mm × 100 mm to 300 mm × 300 mm and use it as a test sample, but it can be arbitrarily set according to the size required for the physical property measurement after the cycle test. Since the test sample may be put into the dryer, the size of the dryer is also limited.

  It is desirable that the roof base material test sample 1 cut out in an appropriate size as described above is fixed on a plate-like table 2 that serves as a solid support as shown in FIG. As the plate-like table 2, a plywood having a thickness of about 12 mm is preferable because it is easy to obtain, but any material that does not readily deteriorate at a temperature of about 80 ° C. may be used, such as a metal plate, a plastic plate, and various fiber plates. It can also be used. These can be cut into the same size as the test sample 1 of the roof base material and used as the table 2. The test sample 1 can be fixed to the upper surface of the table 2 by any method such as driving a nail 3. After fixing the roof base material test sample 1 to the table 2, the frame 4 is attached to the surface of the test sample 1. This frame 4 is used for blocking by putting an acid aqueous solution 5 inside, and is formed of a material having acid resistance and heat resistance, such as a plastic such as acrylic, a metal such as stainless steel, and an inorganic material such as glass. It is what is done. The frame 4 can be formed into a circle or square with a height of 30 to 50 mm, and the acid aqueous solution 5 is prevented from leaking by being in close contact with the surface of the test sample 1 with an adhesive or caulking material. It is.

  In the present invention, an aqueous solution of sulfuric acid, nitric acid or hydrochloric acid can be used as the aqueous acid solution, but an aqueous solution of an acid having relatively low volatility such as sulfuric acid or nitric acid is preferably used. The pH of the acid aqueous solution is preferably in the range of 2.0 to 4.0, more preferably in the range of pH 2.5 to 3.5. By using sulfuric acid or nitric acid as an acid, it becomes easy to reproduce deterioration close to aging during actual use, and by setting the pH in the range of 2 to 4, It is easy to reproduce deterioration close to aging.

Then, the acid aqueous solution 5 is put inside the frame 4, and the acid aqueous solution is supplied to the surface of the roof base material test sample 1. The supply amount of the acid aqueous solution 5 is 0.2 to 1. per 1 cm ² of the surface of the test sample 1 of the roof base material so that the height of the liquid surface of the acid aqueous solution 5 in the frame 4 is about ² mm to 10 mm. It is preferable to set in the range of 0 ml. Thus, after supplying the acid aqueous solution 5 to the test sample 1 of a roof base material, the test sample 1 is put into a dryer and heated. The heating temperature is preferably in the range of 50 to 90 ° C. When the test sample 1 is placed in a dryer set at this temperature and left to stand, the acid aqueous solution 5 evaporates and the surface of the test sample 1 becomes dry. The dryer is preferably capable of adjusting the temperature and circulating the air inside with a fan. The heating time is not particularly limited as long as the moisture of the acid aqueous solution is sufficiently volatilized and the acid sufficiently acts on the roof base material, but by setting it in the range of 6 to 30 hours, It becomes easy to reproduce deterioration close to aging during actual use. The heating time may be changed slightly for each cycle when a plurality of cycles are repeated as will be described later.

Thus, by supplying the acid aqueous solution 5 to the roof base material test sample 1 and heating and drying it, the acid aqueous solution acts on the roof base material under heating conditions, and the roof base material filler and core material Can be simultaneously deteriorated. Here, reproducing the deterioration close to the secular change in actual use by setting the amount of the acid aqueous solution supplied to the test sample 1 of the roof base material to the range of 0.2 to 1.0 ml per 1 cm ^2. In addition, by setting the heating temperature to dry the acid aqueous solution in the range of 50 to 90 ° C., it becomes easy to reproduce deterioration close to aging during actual use. Is.

  As described above, the acid aqueous solution 5 is supplied to the roof base material test sample 1 and heated and dried to promote the deterioration of the roof base material. However, the acid aqueous solution 5 is supplied and dried only once. Then, since the acceleration of deterioration is small, the above-described step of supplying the acid aqueous solution 5 and heating and drying the acid aqueous solution is defined as one cycle, and a plurality of predetermined cycles are repeated. Usually, it is preferable to repeat 10 cycles as a unit.

  After performing the test repeated for a predetermined cycle as described above, the test sample 1 of the roof base material is removed from the base 2, and a test piece is cut out from the portion of the test sample 1 to which the acid aqueous solution 5 is applied, to obtain the tensile strength and elongation rate. Measure mechanical strength characteristics such as. Since the test sample 1 of the roof base material is deteriorated by performing the test of the predetermined cycle, it changes with respect to the mechanical characteristic value of the roof base material in the initial state before the test of the predetermined cycle. Therefore, the degree of deterioration can be known by determining the ratio of the mechanical property value of the roof base material after repeating a predetermined cycle to the mechanical property value of the roof base material in the initial state.

  Here, about the roof base material actually used on the roof of the house, the mechanical property value of the roof base material before construction is measured, and the machine of the roof base material when a predetermined number of years have passed after construction Measure the characteristic value. In this way, the ratio of the mechanical property value of the roof base material that has passed a predetermined number of years in actual use to the mechanical property of the roof base material in the initial state can be obtained. And, as described above, the ratio of the mechanical property value of the test sample 1 of the roof base material after repeated predetermined cycles to the mechanical property value of the roof base material in the initial state is obtained and compared with that of actual use. By, it can be determined that the deterioration state of the test sample 1 of the roof base material after repeating the test of the predetermined cycle corresponds to the number of years after construction in the actual use actually constructed on the roof, The relationship between the number of cycles of repeated tests and the number of years of actual use can be obtained. Accordingly, the test sample 1 of the roof base material is subjected to repeated cycle tests so that the measured mechanical property value is deteriorated until it reaches the limit of durability, and the number of cycles is obtained. It is possible to estimate the useful life of the roof base material in actual use.

  In order to make it possible to automate the measurement of the durability of the roof base material in evaluating the durability of the roof base material as described above, the durability evaluation apparatus for the roof base material as in the configuration of claim 5 Can be formed. Here, as a measuring means for measuring the mechanical strength characteristic value of the roof base material, a tensile test apparatus can be used. In this measuring means, the mechanical strength in the initial state of the roof base material and a predetermined value are used. Each of the mechanical strength characteristic values of the roof base material after repeating the cycle can be measured. The mechanical strength characteristic value in the initial state of the roof base material measured by the measuring means is stored in the storage means, and the storage means is formed by a computer memory or a hard disk. In the processing means, a process of supplying the acid aqueous solution to the roof base material and heating it for a predetermined time to dry the acid aqueous solution as one cycle is performed, and the processing means repeats the predetermined cycle. And a chamber with a built-in heating device. Then, the ratio of the mechanical strength characteristic value of the roof base material measured by the measuring means after repeating the predetermined cycle by the processing means and the mechanical strength measured value in the initial state stored in the storage means is obtained by the calculating means. This calculation means is formed by a CPU of a computer or the like. Further, if necessary, the durability evaluation apparatus is provided with a display means, and a numerical value of a result obtained by the calculation means is displayed on the display means. The display means can be formed by a display such as liquid crystal or CRT.

  Next, the present invention will be specifically described with reference to examples.

Example 1
“Asphalt roofing 940” (JIS A 6005) manufactured by Nanao Kogyo Co., Ltd. was used as a roof base material, and this was cut into 300 mm × 300 mm to obtain Test Sample 1. And the test sample 1 was piled up on the board | substrate 2 which consists of a plywood of the same magnitude | size, and it fixed by hitting the nail 3 in the four corners. Further, a rectangular frame 4 having a thickness of 5 mm, a height of 50 mm, and a vertical and horizontal dimension of 200 mm is made of acrylic resin, and this frame 4 is bonded onto the test sample 1 by silicon caulking (manufactured by GE Toshiba Silicone Co., Ltd.). And fixed.

  Meanwhile, a pH 3 sulfuric acid aqueous solution was used as the acid aqueous solution 5. Then, this acid aqueous solution 5 was poured into the frame 4 so that the height of the liquid surface was about 5 mm and supplied to the test sample 1, and this was put into a dryer at 80 ° C. for 24 hours and dried. The feeding and drying steps of the acid aqueous solution 5 were taken as one cycle, and tests of 10, 20, 30, and 40 cycles were performed.

  And about what performed the test of each cycle, the test sample 1 was removed from the stand 2, and the tension test was done. A tensile test was also performed on the initial state before the cycle test. The tensile test is performed using an autograph “AGS-50A” manufactured by Shimadzu Corporation under the conditions of a measurement temperature of 20 ± 2 ° C., a relative humidity of 65 ± 20%, a measurement gauge distance of 30 mm, and a test speed of 3 mm / min. Strength and elongation were determined.

  In addition, for comparison, the actually used “asphal roofing 940” collected from the remodeling work site was similarly subjected to a tensile test for 10 years after construction and for 20 years after construction.

(Comparative Example 1)
“Asphalt roofing 940” was cut to 300 mm × 300 mm to prepare a test sample, and the test sample was fixed on a table made of plywood of the same size by nailing at four corners. And according to “6. Accelerated aging test A-1 method” of JIS K 6257, the test of 10 cycles, 20 cycles, 30 cycles, and 40 cycles is performed by cooling after heating at 80 ° C. for 24 hours. I did it. And about the thing which tested each cycle, the tension test was done similarly.

(Comparative Example 2)
“Asphalt roofing 940” was cut to 300 mm × 300 mm to prepare a test sample, and the test sample was fixed on a table made of plywood of the same size by nailing at four corners. Then, a cycle of 10 minutes, 20 cycles, and 30 cycles with a humidity test in which the sample is left in an atmosphere of 80 ° C. and 95% relative humidity for 4 hours and then left in an atmosphere of 80 ° C. and 10% or less relative humidity for 20 hours. A 40-cycle test was conducted. And about the thing which tested each cycle, the tension test was done similarly.

  As can be seen in Table 1, the changes in Comparative Examples 1 and 2 are greatly different from the changes in the aged deterioration of the actually used construction products, but the changes in Example 1 are close and those in Example 1 are not. It is confirmed that the same deterioration as the construction product can be reproduced.

It is a perspective view which shows the test method of the test sample of a roof base material.

Explanation of symbols

1 Roof base material test sample 5 Acid aqueous solution

Claims (5)

The step of measuring the mechanical strength characteristic value of the roof base material in the initial state, and the acid aqueous solution is poured inside the frame provided on the surface of the roof base material , and the acid aqueous solution is applied to the surface of the roof base material at a predetermined liquid level The process of evaporating and drying the acid aqueous solution supplied to the surface of the roof base material by heating it for a predetermined time and repeating the predetermined cycle is repeated. Measuring the mechanical strength characteristic value of the roof base material after the step, and determining the ratio between the mechanical strength measurement value in the initial state and the mechanical strength measurement value after repeating the predetermined cycle, The durability evaluation method of the roof base material characterized by this.   The method for evaluating the durability of a roof base material according to claim 1, wherein the acid aqueous solution has a pH of 2 to 4, and a heating temperature for drying the acid aqueous solution is 50 to 90 ° C.   The durability evaluation method for a roof base material according to claim 1 or 2, wherein the acid aqueous solution is an aqueous solution of sulfuric acid or nitric acid. The amount of the acid aqueous solution supplied to the roof base material is 0.2 to 1.0 ml per 1 cm ² of the surface of the roof base material in each cycle. Durability evaluation method of the base material. Measuring means for measuring the mechanical strength characteristic value of the roof base material, storage means for storing the mechanical strength of the roof base material in the initial state measured by the measuring means, and the inside of the frame provided on the surface of the roof base material After supplying the acid aqueous solution to the surface of the roof base material and supplying the acid aqueous solution to the surface of the roof base material, the acid aqueous solution supplied to the surface of the roof base material is evaporated by heating it for a predetermined time. The drying step is one cycle, the processing means for repeating the predetermined cycle, the mechanical strength characteristic value of the roof base material measured by the measuring means after repeating the predetermined cycle by the processing means, and the initial state machine stored in the storage means An apparatus for evaluating the durability of a roof base material, comprising: an arithmetic means for obtaining a ratio with a measured value of the mechanical strength.

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