A method for detecting the amount of rubber powder in rubber asphalt from waste tire rubber powder

Abstract

The present invention discloses a method for detecting the amount of rubber powder in waste tire rubber powder rubber asphalt. The detection method uses the fact that waste tire rubber powder has ash classification substances remaining but asphalt has no residue under high-temperature calcination conditions, and uses the ash classification substances remaining after high-temperature calcination of waste tire rubber powder as a marker, and calculates the amount of rubber powder in waste tire rubber powder rubber asphalt by the amount of ash classification substance residue obtained by high-temperature calcination of waste tire rubber powder rubber asphalt. The present invention has the advantages of convenient operation, strong feasibility, high accuracy, and good reproducibility, and can achieve the effect of "one method and two inspections", which can not only detect the amount of rubber powder in waste tire rubber powder rubber asphalt, but also control the quality of the rubber powder used, which can achieve two goals at one stroke.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber powder content determination in rubber asphalt, and particularly relates to a method for detecting the rubber powder content in waste tire rubber powder rubber asphalt. Background Art

[0002] Rubber asphalt is recognized worldwide as the most effective way to recycle waste tires and reduce the "black pollution" of waste tires. It is not only unique in environmental protection, but also has excellent stability, durability, and anti-skid and noise reduction capabilities.

[0003] The amount of rubber powder in rubber asphalt is an important indicator for evaluating the quality of rubber asphalt, and it is also one of the intuitive ways to evaluate the degree of technological advancement. In principle, the more rubber powder the rubber asphalt absorbs, the better the economy, and the better the social benefits achieved thereby. The preparation of high-content rubber asphalt is an intuitive representation of technological advancement. More and more design documents will require a lower limit for the amount of rubber powder in rubber asphalt. Among the existing rubber asphalts, some have a rubber powder content significantly lower than the normal level, and there is no simple and effective detection method for the amount of rubber powder in rubber asphalt in the existing technical specifications. How to establish an efficient and convenient method for detecting the amount of rubber powder in rubber asphalt is one of the technical problems that technicians in this field urgently need to solve. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for detecting the amount of rubber powder in waste tire rubber powder rubber asphalt.

[0005] The method for detecting the amount of rubber powder in waste tire rubber powder rubber asphalt is to use the fact that under high-temperature calcination conditions, the waste tire rubber powder has ash-classified substances remaining but the asphalt has no residue, and the ash-classified substances remaining after the high-temperature calcination of the waste tire rubber powder are used as markers. The amount of rubber powder in the waste tire rubber powder rubber asphalt is calculated by the amount of ash-classified substances remaining after the high-temperature calcination of the waste tire rubber powder rubber asphalt.

[0006] The specific steps of the method for detecting the amount of rubber powder in the waste tire rubber powder rubber asphalt are:

[0007] (1) Clean and dry the crucible to constant weight, and accurately weigh the mass of each crucible;

[0008] (2) Weigh the waste tire rubber powder sample and the waste tire rubber powder rubber asphalt sample;

[0009] (3) Place the waste tire rubber powder samples in a crucible and calcine them to constant weight. After accurate weighing, subtract the mass of the crucible to obtain the mass of the ash classification substance remaining after calcination of each waste tire rubber powder sample. Divide the mass of the remaining ash classification substance by the mass of the corresponding waste tire rubber powder sample to obtain the residual rate of each waste tire rubber powder sample. The average value is calculated to be the residual rate of the batch of waste tire rubber powder, which is recorded as B.

[0010] (4) After heating the waste tire rubber powder rubber asphalt sample into a fluid state, pour it into a crucible and calcine it to constant weight at the same temperature as the waste tire rubber powder sample. After accurately weighing, subtract the mass of the crucible to obtain the mass of the ash classification material remaining after calcining each waste tire rubber powder rubber asphalt sample. The mass of the residual ash classification material is divided by the mass of the corresponding waste tire rubber powder rubber asphalt sample to obtain the residual rate of each waste tire rubber powder rubber asphalt sample. The average value is calculated to be the residual rate of the batch of waste tire rubber powder rubber asphalt samples, which is recorded as J.

[0011] (5) From this, it can be calculated that the mass of waste tire rubber powder in waste tire rubber powder rubber asphalt = the mass of waste tire rubber powder rubber asphalt × J / B, and the mass proportion of waste tire rubber powder in waste tire rubber powder rubber asphalt is J / B × 100%.

[0012] In the step (2), the waste tire rubber powder samples are weighed by using the quartering method to evenly weigh 3-8 portions of the waste tire rubber powder samples, each portion having a mass of 4-6 g.

[0013] In the step (2), 3-8 portions of waste tire rubber powder and rubber asphalt samples are weighed, each with a mass of 20-100 g.

[0014] The calcination temperature in step (3) is 800-1000°C

[0015] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0016] (1) Easy to operate and easy to implement

[0017] Ash content is a chemical technical indicator in the specifications of my country's road waste tire rubber powder. It is one of the inherent properties of the rubber powder itself. In the present invention, ash content is used as an important indicator to distinguish rubber powder from asphalt. The pyrolysis of rubber powder can be divided into the following three stages: pyrolysis of low-boiling point operating oil, pyrolysis of natural rubber and pyrolysis of synthetic rubber. The rubber powder generally loses weight at around 200°C, which mainly corresponds to the volatilization of the operating oil in the rubber powder. At 300°C, natural rubber and synthetic rubber begin to undergo pyrolysis reaction. At around 500°C, the initial pyrolysis is basically completed. At higher temperatures, only ash-classified substances remain. Asphalt is a dark brown complex mixture composed of hydrocarbons of different molecular weights and their non-metallic derivatives, mainly composed of four types of substances: saturated components, aromatic components, asphaltenes and colloids. Asphalt can be completely volatilized in a muffle furnace at 500°C, with almost no residue.

[0018] The present invention cleverly utilizes the characteristics that waste tire rubber powder still has ash-classified substances remaining under high-temperature calcination conditions, while asphalt has almost no residue, and creatively uses the ash-classified substances in waste tire rubber powder as markers, thereby achieving the measurement and detection of rubber powder content in waste tire rubber powder rubber asphalt. The method is easy to operate, simple in steps, highly feasible, and suitable for supplementing current specifications.

[0019] (2) High accuracy and good reproducibility

[0020] There are reports in published patents on using reagents to dissolve rubber asphalt to measure the amount of rubber powder. After the rubber powder is added to the hot asphalt, the rubber powder particles will absorb the light components in the asphalt to swell, and some will undergo desulfurization and depolymerization reactions, and then dissolve in the asphalt. However, the dissolution method for measuring the amount of rubber powder is cumbersome to operate, requires the use of a large amount of harmful reagents, and there is a problem that the reagents will swell with the rubber powder, thereby affecting the accuracy of the results. The present invention does not require the use of reagents, and only requires high-temperature calcination to calculate the proportion and range of rubber powder in the batch of waste tire rubber powder rubber asphalt. It has high accuracy, and there is no problem of result deviation caused by operating methods, etc., and it has good reproducibility.

[0021] (3) One method for dual inspection, intuitive and efficient

[0022] The current standards in my country have requirements for the ash content of rubber powder, which is also one of the control indicators of the quality of rubber powder itself. The test of the residual rate of rubber powder in the operation method of the present invention is highly similar to the detection of the ash content of rubber powder, and has a significant positive correlation, and can also control the quality of rubber powder. That is, the present invention can achieve the effect of "one method and two inspections", which can detect the amount of rubber powder in waste tire rubber powder rubber asphalt, and control the quality of the rubber powder used, which can achieve two goals at one stroke. DETAILED DESCRIPTION

[0023] The content of the present invention is further described in detail below in conjunction with the embodiments, and these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Those familiar with the art can make various changes or modifications to the present invention, and apply the general principle of this description to other embodiments without creative work, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0024] Example 1

[0025] (1) Prepare 8 high temperature resistant crucibles, clean and dry them to constant weight, and accurately weigh the mass of each crucible using an analytical balance;

[0026] (2) Weigh 4 portions of waste tire rubber powder samples evenly according to the quartering method, and accurately weigh the mass of each portion of rubber powder using an analytical balance; weigh 4 portions of waste tire rubber powder rubber asphalt samples;

[0027] (3) Four portions of waste tire rubber powder samples are placed in four crucibles in turn and calcined in a muffle furnace at 950°C to constant weight. The mass of the ash classification substance remaining after calcination of each portion of the waste tire rubber powder sample is obtained by accurately weighing and subtracting the mass of the crucible. The mass of the remaining ash classification substance is divided by the mass of the corresponding waste tire rubber powder sample to obtain the residual rate of each portion of the waste tire rubber powder sample. The average value is calculated to be the residual rate of the batch of waste tire rubber powder;

[0028] (4) After heating the waste tire rubber powder rubber asphalt sample to a fluid state, pour it evenly into four weighed crucibles, calcine the four crucibles containing the waste tire rubber powder rubber asphalt samples in a muffle furnace at 950° C. to constant weight, accurately weigh and subtract the mass of the crucible to obtain the mass of the ash classification material remaining after calcination of each waste tire rubber powder rubber asphalt sample, divide the mass of the residual ash classification material by the mass of the corresponding waste tire rubber powder rubber asphalt sample to obtain the residual rate of each waste tire rubber powder rubber asphalt sample, and calculate the average value to obtain the residual rate of the waste tire rubber powder rubber asphalt sample of this batch;

[0029] Table 1 Data related to the test of residual rate of waste tire rubber powder

[0030]

[0031] Table 2 Data related to the test of residual rate of waste tire rubber powder and rubber asphalt

[0032]

[0033] (5) According to the data in Table 1 and Table 2, the formula: mass of waste tire rubber powder rubber asphalt × residual rate of waste tire rubber powder rubber asphalt sample / residual rate of waste tire rubber powder was used to calculate that the mass of waste tire rubber powder in the four waste tire rubber powder rubber asphalts was 12.5455g, 13.4647g, 13.2205g and 12.9736g respectively; the proportion of waste tire rubber powder in waste tire rubber powder rubber asphalt was 24.65%, 25.05%, 25.19% and 25% respectively. The average mass proportion of waste tire rubber powder in this batch of waste tire rubber powder rubber asphalt samples was 24.97%.

Claims

1. A method for detecting the amount of rubber powder in rubber asphalt from waste tire rubber powder, characterized in that: The detection method is to use the fact that waste tire rubber powder has ash-classified substances remaining under high-temperature calcination conditions but no residue in asphalt, and to use the ash-classified substances remaining after high-temperature calcination of waste tire rubber powder as a marker, and to calculate the amount of rubber powder in waste tire rubber powder rubber asphalt by the amount of ash-classified substances remaining after high-temperature calcination of waste tire rubber powder rubber asphalt; The specific steps of the detection method are: (1) Clean and dry the crucible to constant weight, and accurately weigh the mass of each crucible; (2) Weigh the waste tire rubber powder sample and the waste tire rubber powder rubber asphalt sample; (3) Place the waste tire rubber powder samples in a crucible and calcine them to constant weight. After accurate weighing, subtract the mass of the crucible to obtain the mass of the ash classification material remaining after calcination of each waste tire rubber powder sample. Divide the mass of the remaining ash classification material by the mass of the corresponding waste tire rubber powder sample to obtain the residual rate of each waste tire rubber powder sample. The average value is calculated to be the residual rate of the batch of waste tire rubber powder, which is recorded as B. (4) After heating the waste tire rubber powder rubber asphalt sample into a fluid state, pour it into a crucible and calcine it to constant weight at the same temperature as the waste tire rubber powder sample. After accurately weighing, subtract the mass of the crucible to obtain the mass of the ash classification material remaining after calcining each waste tire rubber powder rubber asphalt sample. The mass of the residual ash classification material is divided by the mass of the corresponding waste tire rubber powder rubber asphalt sample to obtain the residual rate of each waste tire rubber powder rubber asphalt sample. The average value is calculated as the residual rate of the batch of waste tire rubber powder rubber asphalt samples, which is recorded as J. (5) From this, it can be calculated that the mass of waste tire rubber powder in waste tire rubber powder rubber asphalt = the mass of waste tire rubber powder rubber asphalt × J / B, and the mass proportion of waste tire rubber powder in waste tire rubber powder rubber asphalt is J / B × 100%; The calcination temperature of step (3) is 800-1000°C.

2. The detection method according to claim 1, characterized in that: In the step (2), the waste tire rubber powder sample is weighed by using the quartering method to evenly weigh 3-8 portions of the waste tire rubber powder sample, each portion having a mass of 4-6 g.

3. The detection method according to claim 1, characterized in that: In the step (2), 3-8 portions of waste tire rubber powder rubber asphalt samples are weighed, each with a mass of 20-100 g.

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