Concrete paving blocks with high strength and low weathering

Abstract

The weathering resistance of concrete bricks is enhanced by using glass powder in a concrete composition. The glass powder can reduce the cement content and also produce a pozzolanic reaction, converting free calcium ions in calcium hydroxide into calcium silicate, thereby fixing the calcium ions within the concrete. The composition includes 20 to 25 weight percent (wt.%) of a cement binder material comprising ordinary Portland cement, fly ash, calcium sulfoaluminate cement, and ground granulated blast furnace slag; 10 to 15 weight percent (wt.%) of coarse aggregate; and 32 to 39 weight percent (wt.%) of fine aggregate. The composition further includes 17 to 23 weight percent (wt.%) of glass powder, with a diameter of less than about 75 microns. The water content is 6 to 9 weight percent (wt.%). The resulting paving brick has a dry density of 1800-2200 kg / m 3 .

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 278,109, filed on November 11, 2021, and to U.S. Patent Application No. 17 / 984,217, filed on November 9, 2022, the disclosures of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a composition for concrete paving blocks, and more particularly, to a composition for preparing concrete paving blocks having high strength and low efflorescence. Background Art

[0004] Concrete paving blocks are widely used in sidewalks and roads. Mechanical properties are fundamental criteria for evaluating the performance of concrete blocks, with strength being particularly crucial. While increasing the amount of cement in the concrete composition can improve compressive strength, this also results in increased costs and accelerated weathering. Generally speaking, weathering of cement-based materials occurs when exposed to high humidity levels. This occurs when water containing dissolved mineral salts reaches the surface of the concrete. As the water evaporates, the salts are left on the surface. The mineral salt deposits are typically whitish in color and difficult to remove. While this is not an indication of internal damage, it can be aesthetically pleasing and can lead to product rejection, resulting in financial losses. This can be a long-term problem, especially with colored blocks, due to the strong color contrast between the deposits and the block body.

[0005] Of all dry-cast products, concrete paving blocks (CPBs) are most susceptible to weathering. As the blocks set or harden, they produce free calcium hydroxide, which is soluble in water, even if only slightly. Therefore, free calcium hydroxide can migrate through the hardened concrete to the surface of the concrete blocks, either through mixing water dissolved in fresh concrete or through exposure to rain or dew. Once on the concrete surface, the calcium hydroxide can react with carbon dioxide in the air to form water-insoluble calcium carbonate. The following are the chemical reactions of weathering:

[0006] Ca(OH)2+CO2→CaCO3+H2O→evaporation=weathering

[0007] Generally speaking, there are two types of weathering: primary and secondary. The difference between the two lies in the origin of the substance that causes the weathering. Primary weathering is caused by the elements of the original material's composition within a limited time after the concrete is created. Secondary weathering is caused by environmental conditions, such as exposure to water or other liquids in the form of rain, ice, or dew.

[0008] Therefore, there is a need in the art for improved compositions that have sufficient strength and reduced efflorescence and that can be used to prepare high-strength concrete paving blocks with long life. Summary of the Invention

[0009] The present invention enhances the weathering resistance of concrete bricks by using glass powder in the concrete composition. The use of glass powder reduces the cement content and produces a pozzolanic reaction, converting free calcium ions in calcium hydroxide into calcium silicate. This fixes the calcium ions within the concrete, preventing the calcium hydroxide from reacting with carbon dioxide in the air and causing weathering.

[0010] In one aspect, the present invention provides a weathering-resistant concrete paving slab composition comprising a cement binder material comprising ordinary Portland cement (OPC), fly ash, calcium sulfoaluminate cement (CSA), ground-granulated blast-furnace slag (GGBS), metakaolin (MK), silica fume (SF), or mixtures thereof. The composition further comprises coarse aggregate, wherein at least 90% of the coarse aggregate has a diameter less than about 10 mm, and fine aggregate having a diameter of about 0.75 mm to about 4.75 mm, the composition further comprising glass frit having a diameter less than about 75 microns, water, and optionally a superplasticizer. In the composition, the weight ratio of water to the cement binder material is 0.2 to 0.5. The weight ratio of the coarse aggregate plus the fine aggregate to the cement binder material is 2 to 6. The weight ratio of the fine aggregate to the coarse aggregate is 2 to 5, and the formed paving slab has a dry density of 1800-2200 kg / m 3 .

[0011] In another aspect, the present invention provides a weathering-resistant concrete paving block composition having 20 wt.% to 25 wt.% of a cement binder material comprising ordinary Portland cement (OPC), fly ash, calcium sulfoaluminate cement (CSA), and ground granulated blast furnace slag (GGBS); 10 wt.% to 15 wt.% of coarse aggregate having a diameter of less than about 10 mm; and 32 wt.% to 39 wt.% of fine aggregate having a diameter of less than about 3 mm. The composition further comprises 17 to 23 (19.9) wt.% of glass powder having a diameter of less than about 75 microns, wherein the water content is 6 to 9 wt.%, and the resulting paving block has a dry density of 1800-2200 kg / m 3 . BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a graph of compressive strength and water-cement ratio.

[0013] Figure 2 It is a graph of compressive strength versus aggregate cement ratio.

[0014] Figure 3 It is a graph of compressive strength versus fine-coarse aggregate ratio.

[0015] Figure 4 It is a graph of compressive strength and glass content.

[0016] Figure 5 It is the gradation curve of fine aggregate.

[0017] Figure 6 This is the curve graph for 10mm aggregate.

[0018] Figure 7 It is a scatter plot of 28-day compressive strength.

[0019] Figure 8 Here are photos of two samples after weathering testing.

[0020] Figure 9 Shows the electrical conductivity of the fly ash group.

[0021] Figure 10 Shows the electrical conductivity of the glass frit group. DETAILED DESCRIPTION

[0022] Masonry and cement-based materials with high alkali content are often susceptible to weathering due to the unavoidable formation of soluble salts during hydration during concrete formation. To mitigate weathering in concrete pavers, the present invention provides an appropriate cement content, water-cement ratio, and permeability. Furthermore, since the primary source of free calcium ions, Ca(OH)₂, is generated by cement hydration, the present invention provides a mechanism for consuming the Ca(OH)₂ generated by cement through a pozzolanic reaction. Regarding the water-cement ratio, minimizing it reduces the medium (water) that brings soluble ions to the surface to react with CO₂ in the air. Furthermore, good aggregate gradation enhances permeability and reduces the pores available for soluble salt migration.

[0023] In particular, glass powder is used in concrete compositions to reduce the cement content and, at the same time, reacts to convert free calcium ions in calcium hydroxide into calcium silicate, thereby fixing the calcium ions within the concrete to prevent the calcium hydroxide from reacting with carbon dioxide in the air.

[0024] Various ratios between the different concrete components are provided to establish an appropriate balance between strength, cost and efflorescence reduction. In particular, the present invention provides an appropriate water-cement ratio, aggregate-cement ratio, fine-coarse aggregate ratio and glass content.

[0025] The resulting composition can be formed into low-efflorescence concrete tiles. As used herein, the term "low-efflorescence" means that the developed formula exhibits lower efflorescence than existing formulas, as measured by electrical conductivity and water absorption tests. The electrical conductivity test value can be reduced by more than 20% compared to existing formulas, and the water absorption can be reduced to 2.5% compared to the water absorption of the existing formula (3.91%).

[0026] Water-cement ratio

[0027] Water is one of the essential substances in the cement hydration process; that is, hydration is the chemical reaction necessary to form a strong cement product. Aggregate strength, interfacial bonding strength, and the strength of the cement matrix all contribute to the compressive strength of the concrete brick formed from the composite. The water-cement ratio primarily influences the strength of the cement matrix. Excessive water leads to reduced strength, drying shrinkage, and reduced wear resistance, while a low water-cement ratio results in insufficient hydration and poor workability. Therefore, an optimal water-cement ratio allows for a complete coating to form on the aggregate surface.

[0028] The present invention tested five formulations with water-cement ratios of 0.2, 0.25, 0.3, 0.35, and 0.4, and used the 7-day compressive strength as an indicator. According to previous tests, the compressive strength and dry density have a linear regression equation Y = 0.1628X-297.08. In addition, the sample has density variation. In order to eliminate the influence of density variation, the present invention converts the true compressive strength into 2150 kg / m by the following formula. 3 Compressive strength at fixed dry density:

[0029] P c =P o +0.1628×(2150-ρ . )

[0030] P c : Converted compressive strength

[0031] P o : Actual compressive strength

[0032] ρ o : Actual dry density

[0033] Table 1 shows the water-cement ratios of different compositions to determine the water-cement ratios used in the compositions of the present invention.

[0034] Table 1: Water-cement ratio

[0035]

[0036] The compressive strength-water-cement ratio curve is shown in Figure 1Medium. When the water-cement ratio is low, fluidity is low and the aggregate is not fully coated. Increasing the water-cement ratio enhances bond strength; when the water-cement ratio is high, the aggregate is fully coated; however, excess water reduces the strength of the cement matrix.

[0037] Figure 1 Among the compositions tested, the highest strength water-cement ratio was determined to be 0.32.

[0038] 2. Aggregate-cement ratio and compressive strength

[0039] The strength of the cement matrix is ​​related to both compressive strength and aggregate strength. Aggregate and cement are the primary components of solid concrete. To determine the optimal aggregate-to-cement ratio, the amount of cement is adjusted while maintaining the total solids content. Generally, compressive strength increases with increasing cement content. However, excessive cement can lead to poor fluidity because the cement consumes most of the water. Table 2 shows six test compositions with aggregate-to-cement ratios of 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0.

[0040] Table 2: Aggregate-cement ratio:

[0041]

[0042] As predicted, the compressive strength decreases with increasing aggregate-cement ratio, and the R-squared value is 0.8436, indicating a high correlation. Figure 2 As can be seen from the results, when the aggregate-cement ratio is greater than 3, the compressive strength hardly changes.

[0043] 3. Fine-coarse aggregate ratio and compressive strength

[0044] Coarse aggregate has a large area to volume ratio, so the binder can more effectively connect the coarse aggregate, while the fine aggregate can fill the gaps between the coarse aggregate and enhance the interlocking strength of the concrete. Table 3 shows the five test compositions used to determine the optimal fine-coarse aggregate ratio and compressive strength of concrete. Figure 3 As shown, the compressive strength test composition shows that the optimal fine / coarse aggregate ratio is 4.5, and the compressive strength fluctuates slightly when the fine / coarse ratio is in the range of 4.0 to 5.0.

[0045] Table 3: Fine-coarse aggregate ratio

[0046]

[0047] 4. Glass content and compressive strength

[0048] Glass sand has a similar gradation to fine aggregate, but contains ultrafine glass (<100 μm) to improve compressive strength and optimize aggregate gradation. However, due to its brittle nature, the strength of glass is lower than that of aggregate. To identify the optimal glass content, five compositions with different glass contents were tested. Glass content is defined as:

[0049] By quality.

[0050] like Figure 4 As can be seen in the figure, the compressive strength reaches its peak when the glass content is 0.3, and then slowly decreases. By observing the appearance of the samples, the pits on the surface increase with increasing glass content. Therefore, 0.35 is the optimal glass content, which can both improve compressive strength and avoid surface defects when using glass.

[0051] Table 4: Glass content

[0052]

[0053] Based on the above, a composition for low-efflorescence, high-strength paving blocks includes a cement binder material selected from ordinary Portland cement (OPC), fly ash, calcium sulfoaluminate cement (CSA), ground granulated blast furnace slag (GGBS), or a mixture thereof. The composition further includes coarse aggregate, at least 90% of which has a diameter less than about 10 mm, and fine aggregate having a diameter less than about 0.75 to 4.75 mm. The composition also includes glass frit having a diameter less than about 75 microns, water, and an optional superplasticizer. In the composition, the weight ratio of water to cement binder material is 0.2 to 0.5, the weight ratio of coarse aggregate plus fine aggregate to cement binder material is 2 to 6, and the weight ratio of fine aggregate to coarse aggregate is 2 to 5. The resulting paving block has a dry density of 1800-2200 kg / m 3 .

[0054] The composition may optionally include various recycled components. For example, recycled fine aggregate (e.g., stone fines) and recycled coarse aggregate (e.g., recycled concrete aggregate) may be used, and the glass component may also optionally include recycled glass.

[0055] In another aspect, the present invention provides a weathering-resistant concrete paving block composition having 20 to 25 wt. % of a cement binder material comprising ordinary Portland cement (OPC), fly ash, calcium sulfoaluminate cement (CSA), ground granulated blast furnace slag (GGBS), 10 to 15 wt. % of a coarse aggregate having a diameter of less than about 10 mm, and 32 to 39 wt. % of a fine aggregate having a diameter of less than about 3 mm; the composition further comprising 17 to 23 (optimum 19.9) wt. % of glass powder having a diameter of less than about 75 microns, wherein the weight ratio of water is 6 to 9 wt. %; and the formed paving block has a dry density of 1800-2200 kg / m 3 .

[0056] Examples:

[0057] The example involves determining a low-efflorescence composition using glass powder. Analysis of the raw materials shows that 10 mm aggregate contains approximately 10% fine aggregate, so the 10% fine aggregate is specifically taken into account when calculating the fine to coarse aggregate ratio, that is:

[0058]

[0059] Figure 5 shows the fine aggregate gradation curve, while Figure 6 The 10 mm aggregate curve is shown.

[0060] The moisture content of the solid starting ingredients influences the choice of a specific water-cement ratio. In the plant, operators can measure the moisture content after mixing, and the water-cement ratio can be used as an indicator, with the moisture in the solids increasing the actual water-cement ratio.

[0061] Recycled glass contains almost no moisture. For coarse sand and 10mm aggregate, the moisture content can be measured by the following steps:

[0062] The sample was weighed and placed in an oven.

[0063] After 24 hours, the samples were removed and weighed.

[0064] Compare the mass differences and calculate the moisture content.

[0065]

[0066] The moisture content of the coarse sand is 4.17% while the moisture content of the 10 mm aggregate is 1.01%. Therefore, a drying oven is used to remove the moisture content of the coarse sand and 10 mm aggregate before mixing.

[0067] Sample preparation

[0068] There are two methods that can be used to prepare the sample. One method is to compact the material on a vibration table. By controlling the vibration and load, the height and density are controlled within acceptable ranges.

[0069] Another method is to compact the material without vibration. In the embodiment using the second method, it may not be possible to obtain a very high density sample without vibration.

[0070] Compressive strength test

[0071] The compressive strength in the axial direction was tested using an advanced testing machine with a load rate set at 15kN / s. Prior to the compressive strength test, the mass and height were measured to calculate the dry density.

[0072] Dry density and compressive strength

[0073] Three batches of 80mm paving bricks (each batch containing 54 bricks) were analyzed. The average 28-day compressive strength was 69.04MPa, the maximum 28-day compressive strength was 88.03MPa, and the minimum 28-day compressive strength was 50.4MPa. The relationship between the 28-day compressive strength and the dry density was analyzed by linear regression. The results are shown in Figure 7 The linear regression equation is Y = 0.1628X - 297.08, and the R square value is 0.7753, which is greater than 0.7. Therefore, it can be determined that the dry density has a strong correlation with the 28-day compressive strength. Based on the regression equation, the dry density should not be less than 2100 kg / m 3 , in order to achieve 45MPa compressive strength, considering the possible changes during commercial production, 2150kg / m 3 As the minimum dry density.

[0074] It is important to note that mass loss occurs after mixing. For example, when a weighed mixture is filled into a mold, the mixture may fall or water may evaporate during curing. Therefore, in order to accurately predict the dry density, a correlation between wet and dry densities is further constructed. A set of samples is also prepared to determine the mass loss rate. The mass loss rate is defined as:

[0075]

[0076] Wet mass: the mass of the mixture before filling with materials

[0077] Dry mass: the mass of the paving block after curing

[0078] After removing the inaccurate data of samples 4 and 7, the average mass ratio is 2.30%. Therefore, the designed wet density should not be less than 2200 kg / m 3 .

[0079] Table 5: Mass loss rate

[0080]

[0081] Optimal formula design

[0082] Taking the above factors into consideration, a specific optimal formulation is recorded in Table 6.

[0083] Table 6: Optimal formulation

[0084]

[0085] The above formulations are based on considerations for maximum compressive strength. However, from an environmental and cost perspective, saving 15% of Portland cement is also a goal. Increasing the A / C ratio and reducing the dry density are the two main methods for saving cement. Based on the optimal formulation, six formulations were selected for compressive strength testing in the laboratory. Their height should be 80±2mm, and the 28-day compressive strength should be greater than 45MPa. Generally speaking, the 7-day compressive strength is about 70% of the 28-day compressive strength, but for safety reasons, the 7-day compressive strength must be greater than 38.25MPa (80% of 45MPa) when tested in the laboratory.

[0086] Table 7: Compressive strength of concrete at various ages

[0087] Age Strength percentage 1 day 16％ 3 days 40％ 7 days 65％ 14 days 90％ 28 days 99％

[0088] Table 8: Summary of formulations and results (experimental formulations)

[0089]

[0090] Commercial field trials

[0091] The formulation was adjusted based on industry feedback at a commercial site. Aggregates were exposed to the ground without covering and were not heated prior to mixing. The water-to-cement ratio was substituted by the water-to-solid ratio indicated on a moisture indicator. The moisture indicator displayed a lower value than the actual moisture content. Based on field records, the composition is listed in Table 9. (Note: The F / C ratio values ​​here assume 10% of 10 mm aggregate as fine aggregate.)

[0092] Table 9: Summary of composition and results (commercial trial formulation)

[0093]

[0094] Table 10: Summary of compositions and results (commercial compositions)

[0095]

[0096] Table 11: Summary of commercial trial results

[0097]

[0098] Composition No. 3 exhibited good properties, with an average 28-day compressive strength greater than 55.5 MPa. All samples had a 28-day compressive strength greater than 45 MPa and a height within 80 ± 2 mm. For this batch, the 7-day compressive strength was approximately 90% of the 28-day compressive strength.

[0099] Water absorption characteristic test

[0100] Because Composition No. 3 met the basic requirements, further testing was performed on samples of Composition No. 3. According to AS / NZS 4456.14:2003, the characteristic water absorption of samples after a 24-hour cold water immersion should be less than 6%. The average cold water absorption of these samples was 3%, as shown in Table 12.

[0101] Table 12: Characteristic water absorption

[0102]

[0103] According to the requirements of paving bricks, the anti-slip value should be greater than 60.

[0104] The average unpolished anti-slip value of this sample is 88, as shown in Table 13.

[0105] Table 13 Unpolished anti-slip value

[0106]

[0107] The average value of the compressive strength is 50 MPa, and the characteristic compressive strength is 44 MPa, as shown in Table 14.

[0108] Table 14: Feature Strength

[0109]

[0110] Weathering characteristics

[0111] Weathering acceleration and comparison

[0112] According to the test standard ASTM C67-08, the severity of the weathering level was first assessed visually. Before the test, 5 control samples and 5 experimental samples were prepared. The detailed steps include:

[0113] Step 1: Soak the sample in water at a depth of 25 mm for seven days.

[0114] Step 2: Place the sample in an environmental chamber without contact with water for seven days.

[0115] Step 3: Dry the sample in a drying oven without contact with water for 24 hours.

[0116] Step 4: Observe and compare weathering levels.

[0117] In addition, to investigate the possibility of accelerating the weathering process in concrete specimens, the immersion depth in water was increased from 25 mm to 100 mm, and the contact time with water was extended from 7 days to 14 days.

[0118] The samples for weathering comparison were prepared based on the above optimized formula. Figure 8 As shown in the photos, almost no white deposits were found in the optimized formulation (left), while white weathered deposits leached out in the conventional composition (right).

[0119] Table 15: Compositions used for weathering comparison

[0120]

[0121] Conductivity

[0122] Based on the aforementioned mechanism, efflorescence is primarily caused by soluble ions in the concrete paving slabs. To assess the potential for efflorescence, samples were immersed in deionized water to allow the diffusion of soluble ions, including free calcium, sodium, and potassium ions, into the water. The conductivity of the immersion solution was measured using a conductivity meter. Samples were then immersed in the same volume of deionized water in the same container and measured on days 3, 7, and 14 until a stable ion concentration was reached.

[0123] Based on the optimized composition, the electrical conductivity of the compositions containing fly ash and glass powder in Table 16 was tested; the relevant results are shown in Figure 9 and Figure 10 middle.

[0124] Generally speaking, conductivity increases during the first 7 days and then tends to stabilize. In these groups, the addition of 5% fly ash can reduce the conductivity by 34%.

[0125] Table 16. Formulations used for conductivity comparison

[0126]

[0127] Compared to the fly ash group, glass powder performed poorly in reducing efflorescence, with only 21% at day 7 in the 2.5% glass powder group. After day 7, the conductivity tended to increase (e.g. Figure 7This may be due to the high reactivity of the ultrafine glass powder, which causes the ion concentration to reach equilibrium early.

[0128] Water absorption

[0129] Water absorption is related to the permeability of the paving bricks. If there are more pores in the concrete paving bricks, they can not only absorb more water, but also serve as a path for soluble ions to migrate to the surface of the concrete bricks. In addition, external water (raindrops and dew) can also more easily penetrate into the concrete bricks, causing secondary weathering.

[0130] To demonstrate the effect of ultrafine glass powder or fly ash, samples were prepared according to the compositions listed in Table 17.

[0131] Table 17. Compositions used for water absorption testing

[0132]

[0133] As can be seen from Table 18, the conventional composition has the highest water absorption value (3.91%) among these groups, while the 5% glass frit + 9.5 g SP formulation has the lowest water absorption (2.5%). In addition, due to the higher reactivity of the glass frit group, it has a lower water absorption than the fly ash group.

[0134] Table 18. Water absorption test results

[0135]

[0136] Fly ash content:

[0137] To further enhance the quality of concrete pavers, particularly in terms of long-term compressive strength and weathering control, experiments were conducted using fly ash and glass powder (<75 microns). Given the early-stage effect of glass powder (<75 microns) in accelerating cement hydration, fly ash was the focus of these cement binder experiments. Table 19 shows the results of fly ash replacement of cement at various rates (0 wt.% to 10 wt.%) and the corresponding 28-day compressive strength.

[0138] Table 19. Different replacement ratios and corresponding 28-day compressive strength

[0139] cement fly ash Glass sand 10mm water SP 28-day compressive strength (MPa) Mixture 1-0% 2256.7 0 2221.9 4123.6 2114.1 803.7 4.8 46 Mixture 2-2.5% 2200.3 56.4 2221.9 4123.6 2114.1 803.7 6.5 45.4 Mixture 3-5% 2125.9 112.8 2221.9 4123.6 2114.1 803.7 8 41.1 Mixture 4-7.5% 1974.7 169.2 2221.9 4123.6 2114.1 803.7 8.5 40.6 Mixture 5-10% 2031.1 225.6 2221.9 4123.6 2114.1 803.7 9.5 44.4

[0140] As can be seen from the table, due to the low reactivity of fly ash, the compressive strength of the mixture decreases slightly with increasing cement replacement (fly ash content), however, there is no significant change in compressive strength. Since the compressive strength of the final sample tested (44 MPa) is very close to the original predicted strength (45 MPa), its compressive strength could be further enhanced through water jet curing. In other words, within a certain range (e.g., 5%), replacing cement with fly ash may be a promising approach for maintaining sufficient strength while effectively controlling weathering.

[0141] It will be apparent to those skilled in the art that many modifications other than those already described are possible without departing from the inventive concepts herein. Accordingly, the subject matter of the present invention is not limited except in the spirit of the present disclosure. Furthermore, in interpreting the present disclosure, all terms should be interpreted in as broad a manner as is consistent with the context. In particular, the terms "include / including" and "comprises / comprising" should be interpreted as referring to components, assemblies, or steps in a non-exclusive manner, indicating that the mentioned components, assemblies, or steps may be present, utilized, or combined with other components, assemblies, or steps not expressly mentioned.

Claims

1. A weathering-resistant concrete paving brick composition comprising: A cementitious binder material comprising a mixture of ordinary Portland cement and fly ash, wherein the fly ash in the mixture accounts for no more than 5%; Coarse aggregate, wherein at least 90% of the coarse aggregate has a diameter of less than 10 mm; fine aggregate, wherein the fine aggregate has a diameter of 0.75 to 4.75 mm; Glass powder, wherein the diameter of the glass powder is less than 75 microns; water; as well as Plasticizers; wherein the weight ratio of the water to the cement binder material is 0.3 to 0.35; The weight ratio of the coarse aggregate plus the fine aggregate to the cement binder material is 2 to 6; The weight ratio of the fine aggregate to the coarse aggregate is 2 to 5; as well as The dry density of the paving brick prepared from the composition is 1800-2200 kg / m 3 .

2. The composition according to claim 1, wherein the glass powder is recycled glass powder.

3. A weathering-resistant concrete paving brick, prepared from the composition according to claim 1.

4. A weathering-resistant concrete paving brick composition comprising: 20% to 25% by weight of a cement binder material, wherein the cement binder material comprises a mixture of ordinary Portland cement and fly ash, wherein the fly ash accounts for no more than 5% of the mixture; 10% to 15% by weight of coarse aggregate, wherein the coarse aggregate has a diameter of less than 10 mm; 32% to 39% by weight of fine aggregate, wherein the fine aggregate has a diameter of 0.75 to 4.75 mm; 17% to 23% by weight of glass powder, wherein the glass powder has a diameter less than 75 microns; 6 to 9 weight percent water, wherein the weight ratio of water to cementitious binder material is 0.3 to 0.35; and Plasticizers; The dry density of the paving brick prepared from the composition is 1800-2200 kg / m 3 .

5. The composition of claim 4, wherein the glass powder is recycled glass powder.

6. A weathering-resistant concrete paving block formed from the composition according to claim 4.

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