Polymer mortar material composed of epoxy resin and bottom ash as well as preparation method and application of polymer mortar material

Abstract

The invention belongs to the technical field of new materials, and particularly discloses a polymer mortar material composed of epoxy resin and bottom ash and a preparation method and application thereof.The mortar material comprises an adhesive and bottom ash, the mass percent of the adhesive to the bottom ash is 15%-25%, the adhesive comprises epoxy resin, a curing agent and a diluent, and the curing agent comprises epoxy resin, a curing agent and a diluent. The mass of the diluent accounts for 0-30% of the mass of the epoxy resin, and the mass ratio of the epoxy resin to the curing agent is 2-2.6. According to the polymer mortar material composed of the epoxy resin and the bottom ash as well as the preparation method and the application of the polymer mortar material, the epoxy polymer composed of the epoxy resin and the bottom ash can form a rapid repair material which is high in strength, rapid to form and easy to construct, and the rapid repair material is applied to repair and reinforcement of a damaged concrete structure.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and particularly to a polymer mortar material composed of epoxy resin and bottom ash, a preparation method thereof, and an application thereof. Background Art

[0002] Due to environmental effects such as freeze-thaw cycles, corrosion fatigue, and shrinkage constraints, concrete structures will gradually crack and degrade during use. The durability of concrete structures decreases, and under the combined action of the environment and loads, the service life is greatly shortened and finally damaged. In today's construction industry, repairing and strengthening these damaged concrete structures is a major problem.

[0003] Since the 1980s, polymer mortar materials have been increasingly used for defect and damage repair of concrete structures due to their advantages such as fast curing, high strength, good adhesion, low permeability, and excellent chemical resistance. Polymer mortar is composed of its embedded resin matrix and filling materials. The formation process of the strength and flexibility of the polymer matrix is determined by the chemical reaction between the resin and the curing agent. In the past, researchers have studied different resin systems in polymer mortar. The most commonly used thermosetting resins are vinyl ester, polyester, and epoxy resin. Although vinyl ester and polyester are cheaper, epoxy resin has been more widely used due to its superior mechanical properties, moisture resistance and heat resistance, low shrinkage rate, and high elongation rate.

[0004] Adding filling materials to epoxy resin not only reduces the cost of the epoxy polymer matrix but also improves the mechanical properties and durability of epoxy mortar. This is because the filler has the potential to enhance the filling density of the matrix. The fillers reported in previous studies include fly ash, silica fume, rubber particles, river sediments, red mud, etc.

[0005] The research on some traditional building materials represented by fly ash as fillers for epoxy mortar has been very extensive, but the research on bottom ash as a filler is very little. Bottom ash, as the main by-product of municipal solid waste incineration treatment, contains some heavy metal elements. At present, the main treatment method for bottom ash mainly relies on landfill, etc. However, due to the increasingly scarce land resources, landfill treatment is no longer a feasible option. Many studies are also exploring effective treatment methods for bottom ash. For the treatment of bottom ash, its characteristics should be fully considered. Not only the utilization rate during reuse should be improved, but also the impact of the heavy metal elements contained therein on the environment should be reduced. Using epoxy resin to solidify bottom ash materials can not only produce new building materials with good performance in all aspects, but also the good bonding performance of epoxy resin can well solidify bottom ash and effectively prevent the leaching of harmful substances therein.

[0006] In addition, although polymers composed of epoxy resin and lightweight fillers in specific proportions possess excellent mechanical properties and durability, previous researchers have not paid sufficient attention to the early strength of epoxy polymer systems. The maintenance of certain concrete structures, such as airport runways, highway pavements, bridge decks, and municipal main roads, is subject to heavy traffic flow and frequent damage. Repairing these civil engineering structures not only requires restoring their strength to an acceptable level but also completing the repair within a short period to minimize traffic disruptions. Based on this, another objective of the present invention is to explore whether an epoxy polymer composed of epoxy resin and bottom ash can form a rapid repair material with high strength, rapid forming, and easy construction. Summary of the Invention

[0007] The objective of the present invention is to provide a polymer mortar material composed of epoxy resin and bottom ash, as well as its preparation method and application. The epoxy polymer composed of epoxy resin and bottom ash can form a rapid repair material with high strength, rapid forming, and easy construction, and is applied to repair and reinforce damaged concrete structures.

[0008] To achieve the above objective, the present invention provides a polymer mortar material composed of epoxy resin and bottom ash, including an adhesive and bottom ash. The mass percentage of the adhesive to the bottom ash is 15%-25%. The adhesive includes epoxy resin, a curing agent, and a diluent. The mass of the diluent accounts for 0% to 30% of the mass of the epoxy resin. The mass ratio of the epoxy resin to the curing agent is 2-2.6.

[0009] Preferably, the epoxy resin is bisphenol A epoxy resin, and its chemical structural formula is as follows:

[0010]

[0011] Preferably, the viscosity of the epoxy resin is 9000-14000 mPa·s / 25°C, and the epoxy value is 0.48-0.54 mol / 100 g.

[0012] Preferably, the curing agent is an aliphatic amine curing agent, and its chemical structural formula is as follows:

[0013]

[0014] Preferably, the viscosity of the curing agent is 80-150 mPa·s / 25°C, and the amine value is 600-700 mgKOH / g.

[0015] Preferably, the diluent is C12-14 alkyl glycidyl ether, and its chemical structural formula is as follows:

[0016]

[0017] Preferably, the diluent has a viscosity of 15 CPS / 25°C, an epoxy value of 0.32 mol / 100 g, an organic chlorine value of ≤0.020 mol / 100 g, and an inorganic chlorine value of ≤0.001 mol / 100 g.

[0018] Preferably, the particle size of the bottom ash is less than 4.75 mm.

[0019] The present invention also provides a method for preparing a polymer mortar material composed of epoxy resin and bottom ash, comprising the following steps:

[0020] S1. First, dry the bottom ash in an oven at 100°C for 48 h, and take it out for later use;

[0021] S2. Add epoxy resin and a curing agent into a container, and at the same time add a diluent. After stirring evenly, pour it into the bottom ash and stir well to obtain the polymer mortar material.

[0022] The present invention also provides the application of the polymer mortar material composed of epoxy resin and bottom ash, which is applied to repair and reinforce damaged concrete structures.

[0023] The advantages and beneficial effects of the polymer mortar material, preparation method and application composed of the above epoxy resin and bottom ash in the present invention are as follows:

[0024] 1. The epoxy polymer composed of epoxy resin and bottom ash in the present invention can form a rapid repair material with high strength, rapid forming and easy construction, and is applied to repair and reinforce damaged concrete structures.

[0025] 2. The present invention uses epoxy resin, a curing agent and a diluent as adhesives, and bottom ash as a filler, prepares epoxy mortar specimens with different ratios of adhesive dosages and different ratios of diluent dosages, tests the mechanical properties such as flexural strength and compressive strength of the specimens at different ages, and obtains the optimal ratio of the dosages of the adhesive and the diluent.

[0026] 3. The dosages of the adhesive and the diluent in the present invention jointly affect the early mechanical properties of the specimens.

[0027] The technical solutions of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0028] Figure 1 is the density of the sample after curing for 3 days in the verification example of the present invention;

[0029] Figure 2 is the change in the flexural strength of the specimens in the verification example of the present invention, where (a) is E15, (b) is E20, (c) is E25, and (d) is the specimens cured for 3 d;

[0030] Figure 3It is the change in the compressive strength of the epoxy resin specimen in the verification example of the present invention. Among them, (a) is E15, (b) is E20, (c) is E25, and (d) is the specimen cured for 3 days;

[0031] Figure 4 It is the water absorption rate of the sample in the verification example of the present invention after curing for 3 days and soaking for 28 days;

[0032] Figure 5 It is the compressive strength of the sample in the verification example of the present invention after curing for 3 days and soaking for 28 days;

[0033] Figure 6 It is the MIP result diagram of the verification example of the present invention. Among them, (a) is the proportion of each pore size analogy of the sample and the corresponding total porosity, (b) is the ratio of the cumulative intrusion of the sample to the pore diameter and the ratio of the incremental intrusion of the sample to the pore diameter, and (c) is the ratio of the incremental intrusion of the sample to the pore diameter;

[0034] Figure 7 It is the three-dimensional phase distribution of the sample captured by the X-CT test in the verification example of the present invention. Among them, (a) is E15D0, (b) is E20D0, (c) is E20D15, (d) is E20D30, and (e) is E25D0;

[0035] Figure 8 It is the number of pores of the sample in the verification example of the present invention;

[0036] Figure 9 It is the porosity of the sample in the verification example of the present invention;

[0037] Figure 10 It is the frequency distribution of the sample in the verification example of the present invention;

[0038] Figure 11 It is the frequency of the specimen in the verification example of the present invention. Detailed implementation mode

[0039] The technical solution of the present invention will be further described below with reference to the drawings and embodiments.

[0040] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meaning understood by those of ordinary skill in the field to which the present invention belongs.

[0041] Unless otherwise defined, the reagents, equipment and other materials used in the present invention can all be obtained through regular commercial channels.

[0042] Example 1

[0043] The polymer mortar material composed of epoxy resin and base ash includes adhesive and base ash, the mass percentage of adhesive and base ash is 15%, the adhesive includes epoxy resin, curing agent and diluent, the mass of diluent accounts for 0% of the mass of epoxy resin, and the mass ratio of epoxy resin to curing agent is 2.49.

[0044] The epoxy resin is bisphenol A type epoxy resin, and its chemical structure is as follows:

[0045]

[0046] The viscosity of the epoxy resin is 9000-14000 (mPa·s / 25°C), and the epoxy value is 0.48-0.54 (mol / 100g).

[0047] The curing agent is an aliphatic amine curing agent, and its chemical structure is as follows:

[0048]

[0049] The viscosity of the curing agent is 80 to 150 (mPa·s / 25° C.), and the amine value is 600 to 700 (mgKOH / g).

[0050] The diluent is C12-14 alkyl glycidyl ether, and its chemical structure is as follows:

[0051]

[0052] The viscosity of the diluent is 15 (CPS / 25°C), the epoxy value is 0.32 (mol / 100g), the organic chlorine value is ≤0.020 (mol / 100g), and the inorganic chlorine value is ≤0.001 (mol / 100g).

[0053] The particle size of bottom ash is less than 4.75mm.

[0054] A method for preparing a polymer mortar material composed of epoxy resin and base ash comprises the following steps:

[0055] S1. Dry the bottom ash in an oven at 100℃ for 48h, then take it out and set it aside for use;

[0056] S2. Add epoxy resin and curing agent into a container, add diluent at the same time, stir evenly, then pour into the base ash and stir thoroughly to obtain polymer mortar material.

[0057] The application of polymer mortar materials consisting of epoxy resin and render is used to repair and reinforce damaged concrete structures.

[0058] Example 2

[0059] Different from Example 1, the mass percentage of the adhesive to the base ash is 20%, the mass of the diluent accounts for 10% of the mass of the epoxy resin, and the mass ratio of the epoxy resin to the curing agent is 2.53. The rest is the same as in Example 1.

[0060] Example 3

[0061] Different from Example 1, the mass percentage of the adhesive to the base ash is 25%, the mass of the diluent accounts for 20% of the mass of the epoxy resin, and the mass ratio of the epoxy resin to the curing agent is 2.48. The rest is the same as in Example 1.

[0062] Verification Example

[0063] Epoxy resin, curing agent, and diluent were used as adhesives, and base ash was used as a filler to prepare polymer mortar material specimens with different adhesive dosage ratios and different diluent dosage ratios. The flexural strength and compressive strength and other mechanical properties of the specimens at different ages were tested.

[0064] Preparation of polymer mortar material specimens: First, dry the base ash in an oven at 100 °C for 48 hours. Add epoxy resin and curing agent to a container, and at the same time add the diluent. After stirring evenly, pour the mixture into the base ash and stir well. Finally, pour the completely mixed mixture into a mold with an inner diameter of 40*40*160 mm 3 and tamp it. After curing to the corresponding age, demold it, and then conduct corresponding tests. The above operations were all carried out at room temperature. The ratios of each component of the specimens are shown in Table 1.

[0065] Table 1 Polymer mortar ratio

[0066]

[0067]

[0068] I. Test methods and results.

[0069] 1. Density.

[0070] Use a high-precision electronic balance with a sensitivity of 0.01 g to measure the mass of the specimen after demolding at 3 days of curing. The density of a single specimen is calculated as the ratio of its weight to its volume. By comparing the densities of the mortar under different ratios, analyze the changes in the density of the formed specimens and the polymerization ability of the base ash material with different adhesive contents and diluent dosages.

[0071] Figure 1 Shows the density changes of the epoxy resin specimens in each group after 3 days of curing. The density ranges under different polymer ratios are 1311 kg / m 3 -1583 kg / m 3。According to the experimental results, it can be observed that when the dosage of the diluent is 20%, as the content of the adhesive increases, the density of the specimen first increases and then shows a slight decrease. This may be due to the fact that the increase in the adhesive content leads to the generation of excess voids that the adhesive cannot fill. In addition, when the proportion of the diluent dosage remains unchanged, within the range of 15% to 25% of the adhesive dosage, as the adhesive content increases, the density of the specimen increases. When the diluent dosage is 15%, the epoxy resin specimens are most significantly affected by the adhesive content, rising from 1326 kg / m 3 (15%) to 1523 kg / m 3 (25%), an increase of approximately 14.9%. The increase in density observed in the experiment can be attributed to the increase in the crosslinking density of the epoxy polymer adhesive. During the mixing process, the adhesive can cover the surface of the bottom ash more and fill the voids between the bottom ash, and can better polymerize the bottom ash particles during the compaction process.

[0072] At the same time, it can be seen that when the adhesive dosage remains unchanged, at 15% (E15), 20% (E20), and 25% (E25) respectively, as the diluent increases, the density of the epoxy resin specimens changes slightly but is very close. When the diluent dosage is 25%, the density of the specimen is the largest, being 1355 kg / m 3 , 1483 kg / m 3 and 1583 kg / m 3 . When the adhesive dosage remains unchanged, when the diluent dosage is 25%, the polymerization effect on the bottom ash is the best. Followed by when the diluent dosage is 15%, the densities of the specimens are 1335 kg / m 3 , 1468 kg / m 3 and 1523 kg / m 3 .

[0073] 2. Mechanical strength.

[0074] The specimens were demolded after curing for 1 d, 2 d, and 3 d, and the flexural strength and compressive strength tests were carried out in accordance with the standard of GB / T17671 - 2021.

[0075] Figure 2 In (a)-(c), the changing trends of the flexural strength of the specimens with the increase of the age are shown as the diluent dosage changes under different adhesive dosages. All the test results were obtained by processing the measurement data of three samples. Through the grouped analysis of the test results, the effects of different adhesive dosages and different diluent dosages on the development of the flexural strength of the polymer cement mortar can be determined.

[0076] Overall, within 3 days, regardless of the amount of diluent added, as the age of the specimens increases, the flexural strength of the specimens increases accordingly. In the adhesive system, the epoxy polymers generated by the reaction of epoxy resin, diluent and curing agent partly act as the matrix directly providing strength. The other part wets inside the base ash and acts as an adhesive. The pores in the base ash are reduced by polymer bonding to form a dense whole, further enhancing the strength.

[0077] Polymer cement mortar is a typical early-strength material with relatively high flexural strength, which is much higher than that of ordinary concrete. The strength increment of polymer mortar in the first 4h accounts for about 80% of the total strength, and there is no obvious difference in the mechanical strength between the 3rd day and the 7th day. Therefore, it can be basically determined that the curing time is about 3 days. Figure 2 Figure (d) in the middle shows the numerical change of the compressive strength of the specimens cured for 3 days with the change of the diluent amount under different adhesive dosages. As the diluent amount increases, compared with the polymer mortar without diluent added, the flexural strength of all polymer mortars with diluent added decreases to varying degrees. In the epoxy resin-curing agent-adhesive system, the amine-type curing agent molecules open the oxygen rings at both ends of the epoxy resin and the diluent, and connect with each other on the amine molecules to form a network structure. Therefore, the reactive diluent becomes part of the network structure; however, compared with the harder epoxy molecules, since their aliphatic structure is small and flexible molecules, it increases the flexibility of the epoxy network. The reduction of the epoxy resin skeleton stiffness may lead to the reduction of strength performance. On the other hand, the smaller diluent molecules reduce the viscosity of the epoxy resin, thus improving the wetting performance of the fresh epoxy resin-diluent-hardener mixture. Due to the use of fine fillers in mortar production, the improvement of wetting performance may increase the adhesion between the epoxy mixture, the matrix and the filler particles. Therefore, these dual and opposite effects of using diluent in epoxy mortar interact with each other, and if the former has a greater impact on the strength of polymer cement mortar than the latter, they jointly lead to a decrease in strength to varying degrees.

[0078] From Figure 2 Figure (d) in the middle, it can be seen that regardless of the diluent content, when the adhesive dosage increases from 15% to 20%, the increase in the flexural strength of the specimens is almost above 100%. When the diluent content is 15%, the maximum increase can reach 257.1%. In contrast, when the adhesive dosage increases from 20% to 25%, the increase in the specimen strength is below 60%. When the diluent content is 10%, the minimum increase is only 28.0%. It can be seen from this that when the adhesive dosage is above 20%, the increase in the strength of polymer cement mortar by the adhesive becomes limited.

[0079] Figure 3Figures (a)-(c) show the variation trend of the compressive strength of specimens with the increase of age as the amount of diluent changes under different amounts of adhesive. All the test results are obtained by processing the measurement data of six samples. Similar to the change of the flexural strength mentioned above, overall within 3 days, regardless of the amount of diluent added, as the age increases, the compressive strength of the specimens increases accordingly.

[0080] Figure 3 Figure (d) shows the numerical change of the compressive strength of specimens cured for 3 days as the amount of diluent changes under different amounts of adhesive. As the amount of diluent increases, compared with the polymer mortar without adding diluent, the compressive strength of all polymer mortars added with diluent decreases to varying degrees. As mentioned above, the diluent adheres to the epoxy resin and prevents the growth of molecules by occupying the reaction points of the curing agent (hydrogen atoms connected to nitrogen). Therefore, more diluent means a greater reduction in the reaction points and functions of the curing agent, and thus a greater reduction in the compressive strength.

[0081] When the adhesive content is 15%, 20% and 25%, the corresponding maximum compressive strengths are 9.4 MPa, 23.6 MPa and 35.9 MPa respectively. When diluent is incorporated, the corresponding minimum compressive strengths are 4.2 MPa, 12.2 MPa and 25.1 MPa respectively. The strengths are reduced by 55.3%, 48.3% and 30.1% respectively. It can be seen that as the amount of adhesive decreases, the influence of the incorporation of diluent on the change of the compressive strength of the polymer cement mortar system becomes more significant. This may be because the diluent molecules adhere to the amine curing agent. When the adhesive content is lower, more diluent molecules occupy the reaction points, terminating the growth of epoxy molecules, resulting in a greater decrease in the strength of the polymer mortar mixture.

[0082] 3. Durability.

[0083] To simulate the rainwater and seawater environments that the epoxy-based repair materials may face during use, two solutions were prepared, namely NaCl solution and Na 2 SO 4 (volume fraction of 5%). After the specimens were prepared and cured for 3 days, the specimens were immersed in the solution for 28 days and then the compressive strength of the specimens was measured. At the same time, the mass of the samples before and after immersion needs to be recorded to detect the absorption of water molecules and salt solution by the samples in the solution. The mass change rate ω (%) of the epoxy mortar specimens is shown in formula (1):

[0084]

[0085] where, m 0 represents the mass of the specimen before immersion in the solution, and m t represents the mass of the specimen after the immersion time of "t".

[0086] Figure 4 For the specimens cured for 3 days and immersed in NaCl and Na 2 SO 4 solution for 28 days, the change in water absorption rate. It can be seen that when the dosage of the diluent is 0, with the increase of the dosage of the adhesive, the water absorption rates of the specimens immersed in NaCl and Na 2 SO 4 solution all increase. And the water absorption rate of the specimens immersed in NaCl solution is significantly greater than that in Na 2 SO 4 solution. When the dosage of the adhesive is 15%, 20% and 25%, the corresponding water absorption rates are 13.1%, 8.1%; 14.1%, 9.0% and 15.2%, 10.1% respectively. Such a situation may be because in the NaCl solution environment, there is salt deposition on the surface of the specimens, resulting in a certain increase in the weight of the specimens.

[0087] When the dosage of the adhesive is 20%, with the increase of the diluent, the water absorption rates of the specimens immersed in NaCl and Na 2 SO 4 solution show a slight trend of first increasing and then decreasing, and when the dosage of the diluent is 15%, the water absorption rate reaches the maximum value, which are 14.5% and 9.2% respectively.

[0088] Figure 5 For the specimens cured for 3 days and immersed in NaCl and Na 2 SO 4 solution for 28 days, the change in compressive strength. Generally speaking, the compressive strength of the specimens after immersion can basically reach more than 90% of the original level. When the dosage of the diluent is 0, when the dosage of the adhesive is 15%, the strength of the specimens after immersion in NaCl and Na 2 SO 4 solution remains basically unchanged compared with that before immersion. When the dosage of the adhesive is 20%, the specimens in NaCl and Na 2 SO 4The strength after solution immersion decreased from 14.2 MPa before immersion to 13.3 MPa and 13.4 MPa, a decrease of 6.3% and 5.6% respectively. When the amount of adhesive reached 25%, this figure was even lower, decreasing from 31.3 MPa to 29.1 MPa and 28.9 MPa, a decrease of 7.0% and 7.7% respectively. It can be seen that the higher the content of the adhesive, the greater the decrease in the compressive strength of the specimen. This phenomenon can be explained as follows: the expansion mismatch caused by the diffusion of the solution inside the specimen leads to local deformation, resulting in debonding and cracks between the aggregate and the adhesive, causing a loss of the compressive strength of the specimen. When the adhesive content is low, the porosity and permeability of the specimen are high, and the permeability of the polymer cement mortar specimen decreases with the increase in the amount of adhesive. Chloride ions and sulfate ions in chloride solutions and sulfate solutions migrate into the specimen at the initial stage of immersion and gradually produce CaCl 2 crystals and CaSO 4 crystals. These erosion products will fill the original pores between the base ash, thus enhancing the strength of the specimen. Therefore, when the adhesive content is low, its higher porosity and permeability allow more CaCl 2 crystals and CaSO 4 crystals to fill the pores, thus maintaining the level of the compressive strength of the specimen. With the increase in the amount of adhesive, the decrease in porosity and permeability resists the erosion of chloride ions and sulfate ions, which will lead to a certain degree of decrease in the compressive strength of the specimen. However, with the increase in the immersion time, the combined action of crystallization and swelling pressure will increase the erosion depth of chloride ions and sulfate ions, and the erosion rate of chloride ions and sulfate ions will be greater than the generation rate of erosion products, ultimately leading to a decrease in compressive strength.

[0089] Figure 5 It also shows the influence of the change in the diluent content on the salt solution resistance of polymer cement mortar when the amount of adhesive remains unchanged. When no diluent is added, in NaCl and Na 2 SO 4 solutions, the compressive strength of the specimen decreased by 6.3% and 5.6% respectively. When the diluent content was increased to 15%, the compressive strength decreased by 4.8% and 2.9%. When the diluent content reached 30%, the compressive strength decreased by 4.8% and 0. It can be seen that the addition of the diluent has improved the chemical resistance of polymer cement mortar to a certain extent.

[0090] 4. Mercury intrusion porosimetry (MIP) and X-ray computed tomography (X-CT).

[0091] The mercury intrusion porosimetry (MIP) and X-ray computed tomography (X-CT) were combined to comprehensively study the cementitious pore structure.

[0092] The instrument model used for the MIP test is AUTOPORE9600, with a pressure range of 0.10 psia to 61000 psia and a mercury temperature of 22.08 °C. The X-CT instrument used is the Vtomex type of GE.

[0093] In this invention, five groups of test blocks were selected for experiments, with the mass fraction of the adhesive being 15%, the dosage of the diluent being 0; the mass fraction of the adhesive being 20%, the dosage of the diluent being 0; the mass fraction of the adhesive being 20%, the dosage of the diluent being 15%; the mass fraction of the adhesive being 20%, the dosage of the diluent being 30%; the mass fraction of the adhesive being 25%, the dosage of the diluent being 0. The size of the test blocks is 15mm * 15mm * 15mm.

[0094] The pores in concrete are divided into five parts: <2.5 nm, mainly affecting creep and shrinkage; 2.5 nm - 10 nm, mainly affecting shrinkage; 10 nm - 50 nm, mainly affecting shrinkage rate, strength and permeability; 50 nm - 10 μm, mainly affecting strength and permeability; >10 μm, mainly affecting strength.

[0095] Figure 6 Figure (a) shows the change trends of the total porosity and the pore size distribution of each size. It can be seen that when the dosage of the diluent remains zero, with the increase of the mass fraction of the adhesive, the proportion of small pores gradually increases, and the proportion of large pores gradually decreases. Specifically, the proportion of pores with a diameter of <50 nm gradually increases, while the proportion of pores with a diameter of >10 μm gradually decreases. The former mainly affects permeability, and the latter mainly affects strength. The mass fractions of the adhesive of 15%, 20% and 25% correspond to porosities of 22.1%, 16.5% and 9.8% respectively. The total porosity of the sample decreases with the increase of the mass fraction of the adhesive. With the increase of the adhesive content, the reason for the decrease in porosity can be explained as the increase in the cross-linking density of the adhesive fills the pores and wraps the aggregates, thus reducing the porosity and the pore volume. Figure 6 As can be seen from Figure (b), the higher the adhesive content, the lower the mercury intrusion volume. Figure 6 Figure (c) shows the pore diameter with the widest distribution in the sample under different adhesive dosages. The curve shows that with the increase of the adhesive dosage, the pore size becomes more dispersed, and the pores with different diameters are more evenly distributed. This phenomenon is mainly due to the fact that increasing the adhesive dosage can make the aggregates better coated and lead to further filling of the voids between the aggregates. Thus, it can be seen that the content of the adhesive not only has a great influence on the porosity, but also can change the pore size distribution.

[0096] Specifically, the adhesive dosages of 15%, 20% and 25% correspond to porosities of 22.1%, 17.5% and 9.8% respectively. As is well known, the greater the porosity of the specimen, the lower its durability and strength.Figure 6 As can be seen from (a) in the figure, with the increase in the amount of adhesive, the porosity shows an obvious downward trend, while the proportion of pore sizes <50nm increases from 8% to 20%, and finally reaches 46%. As described above, the permeability of the specimen will also increase accordingly, which can fully explain Figure 4 the water absorption rate of the specimen shown increases with the increase in the amount of adhesive.

[0097] When the amount of adhesive is 20%, the total porosity corresponding to a diluent content of 15% is 16.5%, which is the lowest. From the perspective of pore size distribution, the addition of diluent has only a slight impact on the pore size distribution of specimens with different sizes, and when the diluent dosage is 15%, the proportion of pore sizes >10μm in the specimen is the lowest, at 65%. Therefore, considering the total porosity and pore size distribution comprehensively, the specimen with an adhesive dosage of 20% and a diluent dosage of 15% has better strength and permeability.

[0098] Large pores (all >10μm) were specifically captured through X-CT testing to analyze the pores of polymer cement mortar.

[0099] Figure 7 shows the pore distribution of specimens with different sizes inside under different ratios. Figure 8 and Figure 9 shows the total pore number and porosity of specimens under different ratios. Figure 8 It can be seen that when the diluent dosage is 0, with the increase in the adhesive content, the number of pores inside the specimen gradually decreases. And when the adhesive content remains unchanged, with the increase in the diluent dosage, the number of pores inside the specimen shows a slightly increasing trend relatively. Figure 9 The changing trend of the porosity shown is the same as that of Figure 8 above. As described above, the existence of large pores inside the specimen will affect the mechanical properties of the specimen. Figure 8 and Figure 9 The changing trends of the pore number and porosity exactly verify Figure 2 in (d) and Figure 3The changing trends of the flexural strength and compressive strength shown in Fig. (d). When the dosage of the diluent is 0, increasing the dosage of the adhesive from 15 to 25 results in a decrease in the number and porosity of the specimens, and the corresponding flexural strength and compressive strength gradually increase. When the adhesive content is 20%, with the increase in the dosage of the diluent, the number and porosity also increase, so the corresponding flexural strength and compressive strength gradually decrease. It should be noted that the changes in the number and porosity brought about by the change in the dosage of the adhesive, and ultimately the change in mechanical properties, are much greater than the influence brought about by the change in the dosage of the diluent. When the dosage of the adhesive increases from 15% to 25%, the corresponding decreases in the number and porosity can reach 59.6% and 66.7%, while when the dosage of the diluent increases from 0 to 30%, the corresponding increases in the number and porosity are only 34.4% and 25.3%.

[0100] Figure 10 and Figure 11 Quantitatively analyzed the number and proportion of pores with different equivalent diameters generated inside the specimens under different ratios. Classified according to the pore diameter into 5 intervals: <30μm, 30μm - 50μm, 50μm - 70μm, 70μm - 100μm, and >100μm. It can be seen that when the dosage of the diluent is 0, with the increase in the dosage of the adhesive, the number of pores in different diameter ranges shows a downward trend, and the pore distribution gradually becomes uniform. This changing trend is consistent with the changing trend of the pore diameter in Fig. (a) above Figure 6 above. This indicates that whether it is the small pores affecting the permeability of the specimens or the large pores affecting the mechanical properties, their pore diameter distributions will tend to be average with the increase in the dosage of the adhesive, which is beneficial to the permeability and mechanical properties of the specimens. When the dosage of the adhesive is 20%, the increase in the dosage of the diluent slightly increases the proportion of pores with small pore diameters (<100μm) inside the specimens, while significantly reduces the proportion of pores with large pore diameters (>100μm). When the dosage of the diluent increases from 0 to 15% and 30%, the proportion of large-pore pores decreases from 20.5% to 13.9% and 15.3%. This shows that the addition of the diluent will change the overall porosity of the specimens by significantly changing the proportion of large-pore pores inside the specimens.

[0101] When the dosage of the diluent is constant, the density of the specimens will increase with the increase in the dosage of the adhesive. When the dosage of the diluent is 25%, the densities of the corresponding specimens are the largest, which are 1355 kg / m 3 , 1483 kg / m 3 and 1583 kg / m 3 respectively. When the dosage of the diluent is 15%, the density of the specimens is the second largest, which are 1335 kg / m 3 , 1468 kg / m 3 and 1523 kg / m 3 respectively.

[0102] The dosage of the adhesive and the content of the diluent jointly affect the early mechanical properties of the specimens. The results show that within 3 days, the flexural strength and compressive strength of the specimens will increase with the increase of the curing age. After curing for 3 days, regardless of the content of the diluent, when the content of the adhesive is higher, the early flexural strength and compressive strength of the specimens are higher. When the content of the adhesive increases from 15% to 20%, the flexural strength of the specimens cured for 3 days increases greatly, and the increase rate is above 100%. When the content of the adhesive increases from 20% to 25%, the compressive strength of the specimens cured for 3 days increases greatly. When the content of the adhesive remains unchanged, the addition of the diluent will, to a certain extent, reduce the mechanical properties of the specimens, which is the result of the combined action of the change of the overall wetting performance and curing performance of the adhesive due to the addition of the diluent.

[0103] Epoxy resin cement mortar has good resistance to chloride and sulfate solutions. The mechanical properties of the specimens with different ratios basically can be maintained above 90% of that before immersion in the solution, but with the increase of the adhesive content, the decline rate of the mechanical properties of the specimens increases and the water absorption rate rises. When the content of the adhesive remains unchanged, with the increase of the diluent content, the decline rate of the mechanical properties of the specimens decreases to a certain extent. It can be seen that the addition of the diluent will improve the chemical resistance of the specimens.

[0104] The MIP test is mainly used to study the small pores (<10μm) inside the specimens. It can be seen from the results that with the increase of the adhesive dosage, the total porosity of the specimens decreases, the pore distribution of different pore sizes inside the specimens gradually becomes uniform, the proportion of pores larger than 10μm gradually decreases, and the proportion of pores smaller than 10μm gradually increases, resulting in the gradual increase of the permeability of the specimens and affecting the chemical resistance of the specimens. When the content of the adhesive remains unchanged, when the diluent content is 15%, the specimens have the smallest total porosity and the most uniform pore size distribution.

[0105] The X-CT test is mainly used to study the large pores (>10μm) inside the specimens. It can be known from the results that with the increase of the adhesive dosage, the total porosity of the specimens decreases, and the pore distribution of different equivalent diameter pore sizes becomes more uniform, indicating that the mechanical properties of the specimens are improved. When the content of the adhesive remains unchanged, the addition of the diluent will significantly reduce the pores with a pore diameter larger than 100μm inside the specimens, which is beneficial to the development of the mechanical properties of the specimens.

[0106] Considering comprehensively the factors such as the above-mentioned mechanical properties, durability performance, internal pores, processing performance and cost, the ratio with an adhesive content of 20% and a diluent content of 15% is the optimal one.

[0107] Therefore, the present invention adopts the polymer mortar material composed of the above epoxy resin and bottom ash, as well as the preparation method and application thereof. The epoxy polymer composed of epoxy resin and bottom ash can form a rapid repair material with high strength, rapid forming and easy construction, and is applied to repair and reinforce damaged concrete structures.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A polymer mortar material composed of epoxy resin and base ash, characterized in that: The invention comprises adhesive and base ash, wherein the mass percentage of the adhesive and the base ash is 15%-25%. The adhesive comprises epoxy resin, curing agent and diluent, wherein the mass of the diluent accounts for 0%-30% of the mass of the epoxy resin, and the mass ratio of the epoxy resin to the curing agent is 2-2.

6.

2. The polymer mortar material composed of epoxy resin and primer according to claim 1, characterized in that: The epoxy resin is a bisphenol A epoxy resin, and its chemical structure is as follows:

3. The polymer mortar material composed of epoxy resin and primer according to claim 2, characterized in that: The epoxy resin has a viscosity of 9000-14000 mPa·s / 25° C. and an epoxy value of 0.48-0.54 mol / 100 g.

4. The polymer mortar material composed of epoxy resin and primer according to claim 1, characterized in that: The curing agent is an aliphatic amine curing agent, and its chemical structure is as follows:

5. The polymer mortar material composed of epoxy resin and primer according to claim 4, characterized in that: The viscosity of the curing agent is 80-150 mPa·s / 25° C., and the amine value is 600-700 mgKOH / g.

6. The polymer mortar material composed of epoxy resin and primer according to claim 1, characterized in that: The diluent is C12-14 alkyl glycidyl ether, and its chemical structure is as follows:

7. The polymer mortar material composed of epoxy resin and primer according to claim 6, characterized in that: The viscosity of the diluent is 15 CPS / 25° C., the epoxy value is 0.32 mol / 100 g, the organic chlorine value is ≤0.020 mol / 100 g, and the inorganic chlorine value is ≤0.001 mol / 100 g.

8. The polymer mortar material composed of epoxy resin and primer according to claim 1, characterized in that: The particle size of the bottom ash is less than 4.75 mm.

9. The method for preparing a polymer mortar material composed of an epoxy resin and a base ash according to any one of claims 1 to 8, characterized in that: The steps include: S1. Dry the bottom ash in an oven at 100℃ for 48h, then take it out and set it aside for use; S2. Add epoxy resin and curing agent into a container, add diluent at the same time, stir evenly, then pour into the base ash and stir thoroughly to obtain polymer mortar material.

10. Use of the polymer mortar material composed of epoxy resin and primer as claimed in any one of claims 1 to 8, characterized in that: Used to repair and reinforce damaged concrete structures.

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