Continuous mining and filling gangue grouting filling method

Abstract

The application discloses a gang mining and filling gangue grouting filling method, which comprises the following steps: excavating a branch roadway between an air inlet roadway and an air return roadway in a working face, and arranging a grouting pipe on the top of the branch roadway; installing a monitoring system in the branch roadway; closing the first end opening of the branch roadway to be filled, gradually filling gangue into the branch roadway from the first end to the second end, and synchronously spraying cementing materials during the filling process from bottom to top; after the gangue is filled into the second end of the branch roadway, the second end opening of the branch roadway is closed, high-pressure grouting is carried out in the branch roadway through the grouting pipe, so that all the space in the branch roadway is filled; after a set time of grouting is completed, the stress of the filling body in the branch roadway and the subsidence of the top of the branch roadway are monitored through the monitoring system. The gang mining and filling gangue grouting filling method has the advantages that the filling body formed in the branch roadway has high strength and high support stability.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, in particular to a continuous mining and filling gangue grouting filling method. Background Art

[0002] Shortwall continuous mining technology, with its advantages of flexibility, adaptability, low investment, and rapid results, has effectively recovered various types of coal pillars in mines, achieving remarkable results. Combining continuous mining with backfilling technology has resulted in continuous mining and backfilling technology, solving the challenges of coal resource recovery and solid waste disposal. It has been widely used in numerous mines across key mining areas, recovering significant amounts of coal resources and generating significant technical and economic benefits.

[0003] Continuous mining and continuous filling can be categorized as solid filling, paste filling, and gangue grouting, depending on the filling material. Paste filling systems require significant investment and are relatively costly, hindering their application and development. While solid filling offers advantages such as low investment and low cost, it suffers from disadvantages such as low coal resource recovery and poor filling effectiveness, leading to a gradual decline in its scope of application. Gangue grouting, on the other hand, is prone to poor internal air evacuation, resulting in the grouting failing to fill all gaps between the gangue, resulting in low strength and poor support stability in the filling mass formed by the gangue and grouting. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a continuous mining and continuous filling waste rock grouting filling method, which has the advantages of high strength and high support stability of the filling body formed in the branch tunnel.

[0006] The continuous mining and filling method of waste rock grouting according to the embodiment of the present invention comprises the following steps:

[0007] Dig in and out branch tunnels between the air intake tunnel and the return air tunnel in the working face, and set grouting pipes on the top of the branch tunnels;

[0008] Install monitoring systems in branch lanes;

[0009] The first end opening of the branch tunnel to be filled is closed, and gangue is gradually filled into the branch tunnel from the first end toward the second end, and cementitious material is sprayed synchronously during the gangue filling process from bottom to top;

[0010] After the gangue is filled to the second end of the branch tunnel, the second end opening of the branch tunnel is blocked, and high-pressure grouting is carried out into the branch tunnel through the grouting pipe to fill the entire space in the branch tunnel;

[0011] After the grouting is completed for a set time, the stress of the filling body inside the branch tunnel and the subsidence of the branch tunnel top are monitored through the monitoring system.

[0012] According to the continuous mining and continuous filling gangue grouting filling method of the embodiment of the present invention, during the process of gradually filling the gangue into the branch tunnel, the cementitious material will be sprayed synchronously, and the cementitious material at this time can fill the tiny gaps between the gangue. When the gangue completely fills the branch tunnel, the grouting pipe located at the top of the branch tunnel injects the cementitious material into the tunnel. Under the action of high pressure, the cementitious material can fill the larger gaps between the gangue, as well as the gaps between the gangue and the inner wall of the branch tunnel, without having to pass through a longer path to reach the gaps between the gangue near the bottom of the tunnel as in the related art, thereby avoiding the risk of not being able to reach the gaps between the gangue near the bottom of the tunnel due to insufficient grouting pressure of the grouting pipe. As a result, the filling body finally formed in the branch tunnel has a higher structural compactness, and thus higher strength and stronger support. In addition, the gangue grouting filling method has the advantage of low investment cost compared to solid filling and paste filling.

[0013] In some embodiments, the grouting pipe extends from the first end of the branch tunnel to the second end of the branch tunnel, and the grouting pipe is provided with multiple groups of slurry holes arranged at intervals along the extension direction of the branch tunnel. The first end of the grouting pipe is connected to a mobile grouting machine.

[0014] In some embodiments, a plurality of switch valves are connected in series to the grouting pipe, and the plurality of switch valves are arranged at intervals along the extension direction of the grouting pipe.

[0015] In some embodiments, the method of closing the first end opening of the branch tunnel to be filled, gradually filling the branch tunnel with gangue from the first end toward the second end, and simultaneously spraying the cementitious material in the process of filling the gangue from bottom to top, further includes:

[0016] The cementitious material is sprayed synchronously through the grouting pipe when filling the gangue, and / or the cementitious material is sprayed synchronously through the grouting mechanism when the scraper or the gangue thrower fills the gangue into the tunnel.

[0017] In some embodiments, a flow meter is provided at the first end of the grouting pipe, and a pressure sensor is connected in series between the grouting pipe and the mobile grouting machine.

[0018] In some embodiments, the mobile grouting machine is located in the return air lane, and the intake air lane is provided with one of a scraper conveyor, a shuttle car and a transfer crusher for transporting gangue.

[0019] In some embodiments, the monitoring system includes a stress sensor installed on the tunnel floor and a displacement sensor installed at the center of the tunnel, and the displacement sensor extends from the bottom wall of the tunnel to the top wall of the tunnel.

[0020] In some embodiments, a plurality of the branch gateways are excavated between the air inlet gateway and the air return gateway, the plurality of the branch gateways are arranged at intervals along the extension direction of the air inlet gateway, and the ratio of the width of the isolated support coal pillar formed between any two adjacent branch gateways to the width of the branch gateway is 0.1-0.3.

[0021] In some embodiments, the plurality of the branch gateways are excavated in turn in a manner of every one excavated, every two excavated or every three excavated.

[0022] In some embodiments, the cementing material comprises cement slurry, cement fly ash slurry, gangue cement slurry or high water material slurry. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Fig. 1 is a schematic diagram of the distribution of various components on the working face according to an embodiment of the present application.

[0024] Figure 2 Fig. 2 is a schematic diagram of the distribution of various components in the branch gateway according to an embodiment of the present application.

[0025] Figure 3 Fig. 3 is a schematic diagram of the branch gateway when partially filled with gangue according to an embodiment of the present application.

[0026] Figure 4 Fig. 4 is a schematic diagram of the branch gateway when completely filled with gangue according to an embodiment of the present application.

[0027] Figure 5 Fig. 5 is a schematic diagram of the branch gateway after grouting is completed according to an embodiment of the present application.

[0028] Figure 6 Fig. 6 is a schematic diagram of the arrangement of the branch gateway on the working face according to an embodiment of the present application.

[0029] Figure 7 Fig. 7 is another schematic diagram of the arrangement of the branch gateway on the working face according to an embodiment of the present application.

[0030] REFERENCE SIGNS

[0031] 1, air inlet gateway; 2, air return gateway; 3, branch gateway; 4, gangue; 5, cementing material; 6, grouting pipe; 7, stress sensor; 8, displacement sensor; 9, pressure sensor; 10, on-off valve; 11, mobile grouting machine; 12, scraper conveyor; 13, first retaining wall; 14, second retaining wall; 15, isolated support coal pillar; 16, flow meter. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described in detail below with reference to examples shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0033] The following combination Figure 1-Figure 7 A method for continuous mining and filling with waste rock grouting according to an embodiment of the present invention is described.

[0034] The continuous mining and filling method of gangue 4 according to the embodiment of the present invention comprises the following steps:

[0035] A branch tunnel 3 is excavated between the air intake tunnel 1 and the return air tunnel 2 in the working face, and a grouting pipe 6 is set at the top of the branch tunnel 3;

[0036] Install a monitoring system in branch lane 3;

[0037] The first end opening of the branch tunnel 3 to be filled is closed, and gangue 4 is gradually filled into the branch tunnel 3 from the first end toward the second end, and the cementitious material 5 is sprayed synchronously during the gangue 4 filling process from bottom to top;

[0038] After the gangue 4 is filled to the second end of the branch tunnel 3, the second end opening of the branch tunnel 3 is blocked, and high-pressure grouting is performed into the branch tunnel 3 through the grouting pipe 6 to fill the entire space in the branch tunnel 3;

[0039] After the grouting is completed for a set time, the stress of the filling body inside the branch tunnel 3 and the subsidence of the top of the branch tunnel 3 are monitored by the monitoring system.

[0040] According to the continuous mining and continuous filling method of gangue 4 grouting and filling in the embodiment of the present invention, during the process of gradually filling the branch tunnel 3 with gangue 4, a cementitious material 5 is sprayed simultaneously. At this time, the cementitious material 5 can fill the tiny gaps between the gangue 4. When the gangue 4 completely fills the branch tunnel 3, the grouting pipe 6 located at the top of the branch tunnel 3 injects the cementitious material 5 into the tunnel. Under the action of high pressure, the cementitious material 5 can fill the larger gaps between the gangue 4 and the gaps between the gangue 4 and the inner wall of the branch tunnel 3, without having to traverse a long path to reach the gaps between the gangue 4 near the bottom of the tunnel as in the related art. This avoids the risk of the grouting pipe 6 not being able to reach the gaps between the gangue 4 near the bottom of the tunnel due to insufficient grouting pressure. As a result, the filling body finally formed in the branch tunnel 3 has a higher structural compactness, higher strength, and stronger support. In addition, the method of using gangue 4 grouting and filling has the advantage of low investment cost compared to solid filling and paste filling.

[0041] It should be noted that after grouting is completed through the grouting pipe 6, the grouting pipe 6 and the monitoring system are permanently retained in the branch tunnel 3. After the cementitious material 5 cools down, the stress changes of the formed filling body and the subsidence of the roof of the branch tunnel 3 are monitored by the monitoring system to judge the supporting effect of the filling body, so as to facilitate subsequent corresponding debugging and improvement, or serve as an early warning to ensure the safety of subsequent coal mining.

[0042] In some embodiments, the grouting pipe 6 extends from the first end of the branch tunnel 3 to the second end of the branch tunnel 3. The grouting pipe 6 is provided with multiple groups of slurry holes arranged at intervals along the extension direction of the branch tunnel 3. The first end of the grouting pipe 6 is connected to a mobile grouting machine 11.

[0043] That is, the grouting pipe 6 injects the cementitious material 5 into the branch tunnel 3 through multiple groups of slurry outlet holes, ensuring that the cementitious material 5 is more evenly injected into the gaps between the gangue 4 in different areas of the branch tunnel 3. The setting of the mobile grouting machine 11 can provide high-pressure cementitious material 5 for the grouting pipe 6, and the adjustment of its position in the return air tunnel 2 is flexible and convenient, which can better realize the grouting operation in the grouting pipe 6 in different branch tunnels 3.

[0044] Specifically, a grouting pipe 6 is provided in each branch tunnel 3, and the grouting pipe 6 is located at the center of the roof of the branch tunnel 3 in the width direction of the branch tunnel 3. Each group of grouting holes may include multiple grouting holes arranged at intervals along the circumference of the grouting pipe 6, and the multiple groups of grouting holes are arranged at equal intervals along the extension direction of the grouting pipe 6.

[0045] In some embodiments, a plurality of switch valves 10 are connected in series to the grouting pipe 6 , and the plurality of switch valves 10 are arranged at intervals along the extension direction of the grouting pipe 6 .

[0046] At this time, when the gangue 4 is gradually filled into the branch tunnel 3, the on-off valve 10 on the grouting pipe 6 can be gradually opened, so that the grouting pipe 6 can spray the cementitious material 5 on the gangue 4 being filled, and will not spray it on the area of ​​the branch tunnel 3 that is not filled with gangue 4. This arrangement effectively avoids the need to deploy a new grouting mechanism when filling the gangue 4, effectively reducing the grouting cost.

[0047] Specifically, the switch valves 10 are preferably all manual mechanical valves, and the staff can manually open the switch valves 10 in sequence according to the filling progress of the gangue 4.

[0048] It should be noted that when the grouting pipe 6 sprays the cementitious material 5 during the filling process of the gangue 4, its spraying pressure can be adjusted to be lower than the injection pressure of the last process. At the same time, the concentration of the cementitious material 5 at this time is lower than the concentration of the cementitious material 5 in the last process.

[0049] In some embodiments, the first end opening of the branch tunnel 3 to be filled is closed, and the gangue 4 is gradually filled into the branch tunnel 3 from the first end toward the second end of the branch tunnel 3, and the cementitious material 5 is sprayed synchronously during the gangue 4 filling process from bottom to top, which also includes: synchronously spraying the cementitious material 5 through the grouting pipe 6 when filling the gangue 4, and / or, synchronously spraying the cementitious material 5 through the grouting mechanism when a scraper or a gangue thrower fills the gangue 4 into the tunnel.

[0050] That is, in addition to spraying the cementitious material 5 synchronously through the grouting pipe 6 when filling the gangue 4, the cementitious material 5 can also be sprayed through the grouting mechanism on the scraper or gangue thrower when filling the gangue 4 into the tunnel. The latter can mix the cementitious material 5 and the gangue 4 more specifically and evenly. The combination of the two can better ensure the filling reliability of the cementitious material 5 in the gaps between the gangue 4.

[0051] In some embodiments, as Figure 2 As shown, a flow meter 16 is provided at the first end of the grouting pipe 6 , and a pressure sensor 9 is connected in series between the grouting pipe 6 and the mobile grouting machine 11 .

[0052] The flow meter 16 and the pressure sensor 9 can detect the grouting flow and pressure in the grouting pipe 6 to effectively judge the grouting situation and grouting amount in the branch tunnel 3, and effectively avoid insufficient injection of the cementitious material 5 to affect the supporting strength of the filling body.

[0053] In some embodiments, as Figure 1-Figure 5 As shown, the mobile grouting machine 11 is located in the return air tunnel 2, and the air inlet tunnel 1 is provided with a scraper conveyor 12 for transporting the gangue 4, a shuttle car and one of a transfer crusher.

[0054] One of the scraper conveyor 12, shuttle car and transfer crusher can transport the gangue 4 to the branch tunnel 3 to be filled, so that the gangue thrower in the branch tunnel 3 can quickly fill the gangue 4 in the return air tunnel 2 into the branch tunnel 3, effectively improving the filling efficiency of the gangue 4 in the branch tunnel 3.

[0055] Specifically, if Figure 1 As shown, a scraper conveyor 12 extending along the length direction is provided in the air inlet tunnel 1, and the scraper conveyor 12 extends to the main transport tunnel.

[0056] In some embodiments, as Figure 2-Figure 5 As shown, the monitoring system includes a stress sensor 7 installed on the bottom plate of the tunnel and a displacement sensor 8 installed in the center of the tunnel. The displacement sensor 8 extends from the bottom wall of the tunnel to the top wall of the tunnel.

[0057] Positioning displacement sensor 8 at the center of branch tunnel 3 provides more reliable monitoring of roof subsidence. Stress sensor 7 is installed on the floor of branch tunnel 3, near its center. Both stress sensor 7 and displacement sensor 8 can be electrically connected to an external warning platform via a communication cable, which can be concealed within the floor of branch tunnel 3.

[0058] In some embodiments, as Figure 6 and Figure 7As shown, multiple branch tunnels 3 are excavated between the air intake tunnel 1 and the return air tunnel 2. The multiple branch tunnels 3 are arranged at intervals along the extension direction of the air intake tunnel 1. The ratio of the width of the isolation support coal pillar 15 formed between any two adjacent branch tunnels 3 to the width of the branch tunnel 3 is 0.1-0.3.

[0059] That is, considering the strength of the filling body, by leaving an isolation support coal pillar 15 at the working face, the isolation support coal pillar 15 and the filling body jointly ensure the support strength of the working face, the probability of subsidence when excavating other branch tunnels 3 is lower, and the coal mining safety is higher.

[0060] In addition, by setting the ratio of the width of the isolation and support coal pillar 15 to the width of the branch roadway 3 to be lower than 0.3, it is effectively avoided that the width of the isolation and support coal pillar 15 is too large, which causes low coal resource utilization.

[0061] Specifically, the width of the branch tunnel 3 is generally 4m-6m, and the length is generally 20m-100m.

[0062] In some embodiments, multiple branch tunnels 3 are excavated in sequence by mining every other tunnel, mining every other tunnel, or mining every other tunnel.

[0063] This setting effectively ensures the roof stability and coal seam strength reliability during the excavation of branch tunnel 3, making coal mining safer.

[0064] In some embodiments, the cementitious material 5 includes cement slurry, cement fly ash slurry, gangue 4 cement slurry, or high-water material slurry. In this case, the cementitious material 5 is less expensive and can effectively improve the bonding strength between the gangue 4, thereby increasing the supporting strength of the filling body formed in the branch tunnel 3.

[0065] It should be noted that the cementitious material 5 is preferably a cement fly ash slurry, and the cement fly ash slurry ratio is designed based on the required fill strength. Fill strength is achieved by adjusting the solid particle size distribution of the waste rock 4 and the cementitious material ratio. The waste rock 4 can be excavation waste rock 4, ground waste rock 4, waste rock 4 from coal washing plants, etc., and includes but is not limited to fly ash, gasified slag, etc.

[0066] In addition, the first and second ends of branch tunnel 3 are blocked by first retaining wall 13 and second retaining wall 14, respectively. A cloth strip can be used to seal the gap between each of first retaining wall 13 and second retaining wall 14 and branch tunnel 3. The cloth strip prevents the cementitious material 5 from overflowing from the first and second ends of branch tunnel 3. Furthermore, the gas inside branch tunnel 3 can be discharged through the micropores of the cloth strip as the cementitious material 5 is injected, ensuring reliable injection of the cementitious material 5. An exhaust pipe can also be installed in branch tunnel 3 to facilitate the discharge of gas in the middle section of branch tunnel 3.

[0067] At the same time, the current cost of continuous mining and continuous filling with paste is approximately 100-150 yuan / ton, with a recovery rate of approximately 95%, and the system investment is generally around 150 million yuan. The cost of continuous mining and continuous filling with waste rock and solid filling is approximately 30-50 yuan / ton, with a recovery rate of approximately 50%, and the system investment is generally around 50 million yuan. However, the continuous mining and continuous filling with waste rock and solid grouting and cementing method of this embodiment costs approximately 50-100 yuan / ton, with a recovery rate of 75%-95%, and the system investment is approximately 75 million yuan. This method has comprehensive advantages in terms of coal resource recovery rate, filling cost, and system investment.

[0068] This invention is suitable for recovering corner coal, main lanes, and protective coal pillars in virtually all fully-mechanized mining operations, and is particularly suitable for resource-depleted mines. It boasts strong market competitiveness, broad market prospects, and excellent economic benefits. It is particularly suitable for resource-depleted mines, effectively improving resource recovery rates and extending mine service life.

[0069] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0071] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0072] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0073] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0074] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. A continuous mining and filling gangue grouting method, characterized in that: The following steps are involved: A branch tunnel is excavated between the air intake tunnel and the return air tunnel in the working face, and a grouting pipe is provided on the top of the branch tunnel. The grouting pipe extends from the first end of the branch tunnel to the second end of the branch tunnel. The grouting pipe is provided with a plurality of grouting holes arranged at intervals along the extension direction of the branch tunnel, and the first end of the grouting pipe is connected to a mobile grouting machine; Install monitoring systems in branch lanes; The first end opening of the branch tunnel to be filled is closed, and gangue is gradually filled into the branch tunnel from the first end to the second end by a scraper or a gangue dumper, and cementitious material is sprayed synchronously through the grouting pipe and the grouting mechanism during the gangue filling process from bottom to top; After the gangue is filled to the second end of the branch tunnel, the second end opening of the branch tunnel is sealed, and high-pressure cementitious material is injected into the branch tunnel through the grouting pipe to fill the entire space in the branch tunnel. The concentration of the high-pressure cementitious material is higher than the concentration of the cementitious material sprayed during the filling process. After the high-pressure cementitious material is injected for a set time, the stress of the filling body inside the branch tunnel and the subsidence of the branch tunnel top are monitored through the monitoring system.

2. The continuous mining and filling gangue grouting method according to claim 1, characterized in that: A plurality of switch valves are connected in series on the grouting pipe, and the plurality of switch valves are arranged at intervals along the extending direction of the grouting pipe.

3. The continuous mining and filling gangue grouting method according to claim 1, characterized in that: A flow meter is provided at the first end of the grouting pipe, and a pressure sensor is connected in series between the grouting pipe and the mobile grouting machine.

4. The continuous mining and filling gangue grouting method according to claim 1, characterized in that: The mobile grouting machine is located in the return air lane, and the air inlet lane is provided with one of a scraper conveyor, a shuttle car and a transfer crusher for transporting gangue.

5. The continuous mining and filling gangue grouting method according to claim 1, characterized in that: The monitoring system includes a stress sensor installed on the bottom plate of the tunnel and a displacement sensor installed in the center of the tunnel. The displacement sensor extends from the bottom wall surface of the tunnel to the top wall surface of the tunnel.

6. The continuous mining and filling gangue grouting method according to any one of claims 1 to 5, characterized in that: A plurality of branch tunnels are excavated between the air intake tunnel and the return air tunnel, and the plurality of branch tunnels are arranged at intervals along the extension direction of the air intake tunnel. The ratio of the width of the isolation support coal pillar formed between any two adjacent branch tunnels to the width of the branch tunnel is 0.1-0.

3.

7. The continuous mining and filling gangue grouting method according to claim 6, characterized in that: The plurality of branch tunnels are excavated in sequence by mining one every other tunnel, mining one every other tunnel, or mining one every other tunnel.

8. The continuous mining and filling gangue grouting method according to claim 1, characterized in that: The cementitious material includes cement slurry, cement fly ash slurry, gangue cement slurry or high water material slurry.

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