Performance Introduction

With the development of passenger and freight transportation in my country, the burden of road transportation has increased sharply in recent years. Due to the early underestimation of road load, long-term disrepair of roads, the increase in vehicle tonnage, acid rain erosion, and extreme weather such as large-scale snowfall in the south in winter, the road surfaces of highways at all levels across the country have peeled, flaked, potholes, and even collapsed to varying degrees. Therefore, many roads are in urgent need of repair or even reconstruction. However, the most severely damaged roads are often those sections with important traffic positions, and it is difficult to achieve long-term closed construction.

The use of SY-D geopolymer grouting materials can realize trenchless construction of road repairs. The roadbed and base layer can be reinforced by injecting the slurry under the original road surface with a special grouting pump. According to the actual needs of the project, the company has developed three types of geopolymer grouting materials, namely SY-D geopolymer grouting materials for foundation reinforcement, SY-D base layer reinforcement (fast setting and early strength type) geopolymer grouting materials, and SY-D base layer reinforcement (ordinary type) geopolymer grouting materials.

Damage caused by water accumulation in the road foundation is a major cause of road foundation settlement and reflection cracks on the road surface. The usual method is to dig the access road and then replace the foundation, which not only consumes a lot of manpower, financial resources and material resources, but also seriously affects the traffic of the relevant roads. After the SY-D foundation reinforcement geopolymer grouting material produced by our company is injected into the foundation through a grouting pump, the soft foundation can be effectively solidified to achieve trenchless reinforcement of the road foundation.

The reinforcement of the road base is crucial to ensure the quality of the road. According to the different construction periods, our company has developed two types of grouting materials for base reinforcement. Among them, the SY-D base reinforcement (ordinary type) geopolymer grouting material has a relatively low price and a relatively long operation time, which is suitable for use in situations with sufficient construction period.

For some heavy traffic sections, when the traffic closure time is short, the reinforcement materials will be required to set and harden quickly. At this time, the road rapid repair materials must meet the following requirements: (1) Appropriate fluidity to meet the needs of pouring density and construction and operation workability and simplicity. (2) Super early strength, which can quickly reach the designed initial strength, and the later strength can continue to increase under the load to reach the designed final strength. (3) Good volume stability, the expansion rate is kept within a very small range during the entire age from hardening to the full service life. (4) High bonding strength with the old foundation to ensure a close connection between the new and old materials. SY-D geopolymer grouting material for base reinforcement (fast setting and early strength type) is designed based on the above requirements: (1) The initial setting time of the slurry is ≥45min, ensuring sufficient operation time during construction; the 30min fluidity of the slurry is controlled at 20~35s to ensure the self-compactness of the pouring. (2) The 2h flexural strength of the material is ≥2.0MPa and the compressive strength is ≥15.0MPa, ensuring that it can quickly harden to the designed initial strength and enter the next process in time; the 1d, 3d, 7d, and 28d strength of the material increases steadily and its 28d strength is ≥60.0MPa, ensuring that the final strength required by the design can be achieved. (3) The 3h, 3d, and 28d free expansion rates of the material are all controlled within 0.5~1.0%, ensuring that the material has excellent volume stability after hardening.

(4) The 28d tensile bonding strength of the material is ≥2.0MPa, ensuring that the material is tightly connected to the old foundation after hardening.

The above indicators of SY-D geopolymer grouting material only represent the performance of the company's general products. For special requirements of customers on certain aspects of performance, appropriate adjustments can be made based on the provided technical indicators, design data, etc. to meet actual needs.

 

Product manual

Product composition: SY-D geopolymer grouting material is prepared by high-efficiency water reducer, activator, rheological agent, micro-expansion agent, thickener, metakaolin, fly ash and other mineral admixtures in appropriate proportions.

Main features: Change the road repair process to achieve trenchless reinforcement; good water resistance, suitable for the reinforcement of foundations and bases with high water content, excellent durability after solidification: good fluidity, small flow rate out of the machine and half-hour flow loss, ensuring good filling of the slurry; convenient construction, add the rated amount of water and stir it before use.

Application scope: SY-D geopolymer grouting material is suitable for the reinforcement and rapid repair of foundations and bases of highways at all levels and other similar repair projects.

Usage: Mix SY-D geopolymer material with water according to the water consumption indicated in the product manual at the project site, stir evenly with a high-speed mixer, and inject the slurry into the project site through a grouting pump.

Implementation standard: SY-D geopolymer material performance index complies with: SZ-G-B04-2007

Technical index: Mechanical properties determined by the admixture used in the project. Water consumption is 35-40%, and specific technical indexes are shown in Table 1. (Insert a table)

Packaging and storage: 25Kg/bag moisture-proof bag packaging, attention should be paid to moisture-proof during storage, and the product should be used up as soon as possible after opening the bag. If it is stored for more than 3 months or agglomeration occurs, it can be used only after passing the test.

Table 1 SY-D Geopolymer Grouting Materials

Project Type	Fluidity (s)	Initial Setting Time (min)	Final Setting Time (min)	Bleeding Rate (%)	Expansion rate (%)	Water resistance (%)	Compressive strength (Mpa)
							ld	7d	28d
For roadbed reinforcement	≤17.00	≥30	≤400	≤0.40	0.01	95	0	≥2.47	≥4.2
For base reinforcement (fast setting and early strength type)	≤20.00	≥10	≤30	≤0.40	0.01	95	≥20.0	≥25.0	≥30.0
For base reinforcement (Ordinary type)	≤20.00	≥10	≤400	≤0.40	0.01	95	≥5.0	≥20.0	≥30.0

Construction methods and process requirements

1. Construction preparation

(1) Before construction, the deflection of the entire road section shall be tested, and the grouting area shall be determined based on the test results. The deflection test shall be conducted at a section every 20m, and the deflection of each lane on the left and right sides of each section shall be tested separately.

(2) After the grouting range is determined, the geopolymer grouting section shall be marked and holes shall be arranged, and safety and technical instructions shall be provided to the construction team and workers.

(3) The mix ratio of the geopolymer grouting mixture shall be verified to be qualified, the geopolymer grouting material shall be qualified after on-site retest, and the river water used for mixing shall be tested to be free of harmful components and shall not be acidic.

(4) Before the construction of continuous reinforced concrete, all kinds of construction machinery and auxiliary tools shall be fully prepared and kept in good working condition.

(5) After all construction tools and equipment enter the site, they should be piled on the road surface that does not hinder construction; during the drilling and grouting stages, the cleaning of the on-site roads should be strengthened, and sufficient wooden or plastic pads should be laid in the non-operating areas to ensure that construction personnel can pass through the grouting area.

(6) The equipment must be equipped with pressure gauges, flow meters, data storage and printing equipment, and the metering meters should be calibrated; the flowability meter must be self-calibrated on site before use, and the generator, grouting equipment and other machinery must have safety protection facilities.

2. Resource allocation plan

According to the design requirements and the actual situation on site, the construction machinery and tools equipped in this plan and their quantity are shown in Table 2, and the labor allocation plan is shown in Table 3.

Table 2 Main construction equipment equipment table

Serial number	Equipment name	Specifications	Unit	Quantity	Remarks
1	Drilling equipment	φ70	Unit	1
2	Hydraulic grouting pump	HYB-50/50-1	SET	2
3	Lime (sand) mortar mixer	400L, speed 800~2000r/min	SET	1
4	submersible pump	Hit 50	tower	2
5	water tank	2t	Only	1
6	Mobile generator	45kw	1
7	Truck	4t	Vehicles	1
8	Data storage and printing equipment	One	Units	1

 

Table 3 Labor force planning table for each shift

Serial number	Type of work	Quantity	Remarks
1	Mechanical operator	3 people
2	General worker	3 people

 

3. Measure the hole layout According to the design requirements, the hole spacing is tentatively set at 1-2m (it can be slightly adjusted according to the actual situation); the cross layout is in the shape of a "plum blossom", all of which are vertical holes. The plan layout of the grouting holes is shown in Figure 1. After the grouting holes are laid out, a release hole should be left. One release hole should be set for each of the four grouting holes, and the adjacent grouting holes can be used as release holes. The grouting hole diameter is selected to be φ50mm (the diameter of the grouting pipe is φ32mm).

 

Figure 1 Grouting hole layout

4. Drilling

(1) For road base reinforcement, the grouting depth should be based on penetrating the road base and reaching the bottom surface of the base. The scope of base reinforcement is determined according to the on-site conditions. The main function is to restore the integrity of the original three-slag base.

(2) For soil roadbed reinforcement, the grouting depth should be 80cm below the top surface of the roadbed. See Figure 2 for the cross-section diagram of drilling grouting.

(3) Drill holes to the designed depth. If any abnormality is found, appropriate measures should be taken.

Figure 2 Drilling grouting section

5. Slurry preparation

(1) Requirements before mixing: Add water and run the mixer for a few minutes to drain the accumulated water and make the inner wall of the mixer fully wet. The mixed mortar should be basically unloaded. Unmixed materials should not be added before all the mortar is unloaded, and the method of discharging and feeding at the same time should not be adopted. While meeting the fluidity requirements, reduce the amount of water as much as possible and avoid adding too much water.

(2) Pour the weighed water and geopolymer grouting material into the mixer and stir.

(3) Pump the material as soon as possible after discharge, otherwise stir it continuously.

(4) According to the geopolymer grouting regulations and the technical specifications of geopolymer grouting materials, increase the fluidity control of geopolymer grouting materials, and require the fluidity to be no more than 20s.

(5) For grouting materials that have not been used in time and have reduced fluidity, it is strictly forbidden to use the method of adding water to improve the fluidity of the mortar.

6. Grouting

(1) The grouting pipe adopts straight pipe grouting. During the grouting process, the road facilities around the grouting area should be monitored to prevent the road surface from lifting or slurry loss. The lifting height of the road surface should be controlled during the grouting process, and the road surface lifting should not exceed 3cm.

(2) Add the grouting material to the grouting pump. When the slurry concentration discharged from the high-pressure rubber tube outlet of the grouting pump is the same as the concentration in the grouting pump, connect the high-pressure rubber tube to the grouting pipe of the hole and fix it;

(3) Observe the slurry discharge from the release hole. When the slurry consistency is the same as before grouting, continue grouting for 1~2 minutes.

(4) During the grouting process, the grouting pressure of the base layer is controlled at about 0.3 MPa, and the grouting pressure of the roadbed is controlled at 1.2~1.5MPa.

(5) After the grouting is completed, the pipe can be pulled out only when the slurry reaches the initial setting state.

(6) After pulling out the pipe, it should be sealed with a wooden plug in time to ensure that the hole is filled densely. After the hole is finally set, the hole should be filled with mortar in time.

(7) After the grouting construction is completed, the road deflection detection should be carried out according to the design requirements. For unqualified parts, the holes should be re-filled and grouting should be carried out to reach the designed deflection value.

(8) When grouting geopolymer, construction records such as hole spacing, depth, pressure, flow rate and material consumption should be kept.

7. Maintenance

After grouting reinforcement with fast-setting and early-strength geopolymer materials, the closed curing time should be 4~8h, and after grouting reinforcement with ordinary geopolymer materials, the closed curing time should be 1~3d

With the development of passenger and freight transportation in my country, the burden of road transportation has increased sharply in recent years. Due to the early underestimation of road load, long-term disrepair of roads, the increase in vehicle tonnage, acid rain erosion, and extreme weather such as large-scale snowfall in the south in winter, the road surfaces of highways at all levels across the country have peeled, flaked, potholes, and even collapsed to varying degrees. Therefore, many roads are in urgent need of repair or even reconstruction. However, the most severely damaged roads are often those sections with important traffic positions, and it is difficult to achieve long-term closed construction.