Composite curing agent and in-situ filling construction process using the same

Abstract

The application relates to a construction technology of on-site filling with a composite curing agent and the composite curing agent, which comprises the following steps: before construction, the ground elevation of the center line of a road is surveyed, filling material is tested and analyzed, a filter cake is cut into pieces by a crusher to form uniform soil material, the soil material is transported to a construction site, and is then spread, a curing agent formed by uniformly mixing blast furnace slag, gypsum powder, high water absorption resin and non-ionic polyacrylamide is uniformly spread on the soil material and is mixed for multiple times to form a mixture, a layer of the soil material is spread on the mixture, a layer of quicklime is uniformly spread on the soil material, and a road mixer is used to uniformly mix the quicklime, compaction, maintenance and quality acceptance are carried out, the composite curing agent comprises the blast furnace slag, the quicklime, the gypsum powder, the high water absorption resin and the polyacrylamide, and compaction, maintenance and quality acceptance are carried out, the construction technology saves a large amount of construction period, improves engineering construction efficiency and improves the stability of a roadbed structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a composite curing agent and a site filling construction process using the composite curing agent. BACKGROUND

[0002] Traffic engineering in China is developing rapidly, and the traffic network is becoming more and more convenient. However, a large amount of roadbed filling material is often needed for traffic engineering construction, resulting in a shortage of filling material resources. At the same time, the state is continuously strengthening environmental protection, and the exploitation of sand and stone filling materials is decreasing year by year, further exacerbating the shortage of roadbed filling materials, seriously affecting the development of traffic engineering.

[0003] At present, the disposal idea of solid waste by using waste soil as roadbed filling material is popular, and the waste soil is usually made into mud cake through pressure filtration and solidification, and then used as filling material. However, due to the influence of material source conditions and production conditions, the performance of the pressure filtration mud cake varies greatly, the water content is generally high, the strength is low, and the pressure filtration mud cake cannot be directly used as roadbed filling material, especially after being soaked in water, it is easy to soften and even collapse, and the poor water stability of the pressure filtration mud cake has become one of the key problems restricting the development of related technical processes.

[0004] In order to improve the performance of the pressure filtration mud cake, the main method at present is to carry out solidification treatment, and cement, lime, fly ash and the like are usually used as solidifying agents. Although the strength is improved, the water stability of the pressure filtration mud cake is still seriously insufficient after being solidified by cement, lime and fly ash, especially in the rainy season, the roadbed base is easy to cause large deformation and damage, resulting in engineering hazards such as roadbed subsidence, collapse and sliding. Therefore, it is of great significance to improve the water stability of the roadbed filling material and reduce the strength loss under water immersion, so as to improve the stability and service life of the roadbed structure. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application aims to provide a composite curing agent which can play a decisive role in the conversion between the pressure filtration mud cake and the roadbed filling material, effectively solving the problem of waste pressure filtration mud cake, and a site construction process using the composite curing agent, which can save a lot of construction period, improve the efficiency of engineering construction and improve the stability of the roadbed structure.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: To achieve the above-mentioned purpose, the present application provides the following technical solutions: a site filling construction process using a composite curing agent, which is as follows:

[0007] Step S1: Before construction, the ground elevation of the center line is surveyed and checked with the design longitudinal section, after the road center stake is measured and set, the filling roadbed boundary is measured and set according to the design drawing, and the road elevation control stake is measured and set according to the road stake number.

[0008] Step S2: filler test analysis, composite curing agent includes blast furnace slag, quicklime, gypsum powder, non-ionic polyacrylamide, superabsorbent resin, take filter cake and composite curing agent for cooperation design, and determine the water content, liquid-plastic limit, maximum dry density, unconfined compression test, water stability test.

[0009] Step S3: the filter cake is cut by the agglomerated material shredder, and the large soil blocks are stirred to form uniform soil material, which is placed in the aggregate tank.

[0010] Step S4: the soil material is transported to the construction site for paving, and the curing agent mixed uniformly by blast furnace slag, gypsum powder, superabsorbent resin and non-ionic polyacrylamide is uniformly paved on the soil material, and the road mixer is used for loose mixing for multiple times, so that the soil material and the composite curing agent are uniformly mixed to form the mixture.

[0011] Step S5: on the basis of the mixture, a layer of soil material is paved, a layer of quicklime is uniformly paved on the basis of the soil material, and the road mixer is used for uniform mixing.

[0012] Step S6: filler stirring, paving and recompaction, multiple times of rolling are adopted by using a 25t road roller, so that the compaction degree of the filler reaches the requirement, and the road surface is ensured to be free of wheel marks.

[0013] Step s7: roadbed finishing and forming, the level gauge, the line and the ruler are used to check the elevation and flatness, and the roadbed is finished and formed.

[0014] Step s8: after each construction section is completed and the compaction degree is checked and qualified, the corresponding plastic film is paved on the road surface, and maintenance is carried out.

[0015] Step s9: quality acceptance, after the maintenance is completed, the core is taken from the formed base layer, and the compaction degree, strength and water content are tested.

[0016] Further, in the test in step S2, the components in the composite curing agent and the percentage of the mass of the soil body are as follows: the blast furnace slag accounts for 6% to 8% of the mass of the soil body, the quicklime accounts for 3% to 5% of the mass of the soil body, the gypsum powder accounts for 1% to 2% of the mass of the soil body, the superabsorbent resin accounts for 0.1% to 0.2% of the mass of the soil body, and the polyacrylamide accounts for 0.2% to 0.4% of the mass of the soil body.

[0017] Further, in the test in step S2, the components in the composite curing agent and the percentage of the mass of the soil body are as follows: the blast furnace slag accounts for 8% of the mass of the soil body, the quicklime accounts for 4.4% of the mass of the soil body, the gypsum powder accounts for 2% of the mass of the soil body, the superabsorbent resin accounts for 0.2% of the mass of the soil body, and the polyacrylamide accounts for 0.4% of the mass of the soil body.

[0018] The beneficial effects of the application are as follows:

[0019] 1、The composite curing agent includes blast furnace slag, quicklime, gypsum powder, super absorbent resin and polyacrylamide. The quicklime reacts with water in the soil to generate calcium hydroxide to provide an alkaline environment. The calcium hydroxide reacts with the blast furnace slag to generate hydrated calcium silicate gel and hydrated calcium aluminate, which produces a cementing effect between the soil particles. The hydrated calcium aluminate further reacts with the gypsum powder to generate hydrated calcium sulphoaluminate crystals (ettringite) to fill the pores between the soil particles. The non-ionic polyacrylamide has strong adhesion, and its molecular chain is fixed on the surface of different soil particles to play a bridging role between the soil particles, so that the soil is cemented to form a network structure, thereby enhancing the structural strength. The super absorbent resin can absorb water in the filter cake to make the filter cake more fully mixed during the mixing process, thereby improving the uniformity of the cured soil. The cementing material and crystalline material generated through the above series of reactions can effectively improve the strength and water stability of the soil material.

[0020] 2、The on-site filling construction process using the composite curing agent directly mixes the soil material and the composite curing agent in a loosening manner, which can avoid the paving and drying of the soil material, save a large amount of construction period, and improve the efficiency of engineering construction.

[0021] 3、The on-site filling construction process includes two loosening and mixing processes. The first loosening and mixing process uniformly mixes the soil material and the blast furnace slag, gypsum powder, super absorbent resin and non-ionic polyacrylamide in the composite curing agent. In the second loosening and mixing process, the loosening of the soil body produces gaps that are beneficial to air flow, thereby rapidly reducing the water content of the mixture. Quicklime is added in the second mixing process to absorb water in the filter cake, improve the combination of water in the filter cake and the surface of the soil particles, and facilitate the loosening and mixing. In addition, the mixing process shortens the carbonation reaction of the quicklime and carbon dioxide in the air, avoids the deterioration of the quicklime, and affects the full reaction with other components, thereby reducing the strength and water stability of the soil material. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The present application relates to a cured filter cake and a roadbed filling construction process thereof. DETAILED DESCRIPTION

[0023] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific embodiments, structures, features and effects of the present application will be described in detail below with reference to the drawings and preferred embodiments.

[0024] Example 3

[0025] An on-site filling construction process using a composite curing agent includes the following steps:

[0026] Step S1: Before construction, the current ground elevation of the road centerline is surveyed and checked with the design longitudinal section. After the road center stake is measured and set, the fill roadbed boundary is measured and set according to the design drawings, and the road elevation control stake is measured and set according to the road stake number;

[0027] Step S2: Fill material testing and analysis, composite curing agent includes blast furnace slag, quicklime, gypsum powder, non-ionic polyacrylamide, and superabsorbent resin. The pressure filtration mud cake is mixed with the composite curing agent for design, and the water content, liquid-plastic limit, maximum dry density, unconfined compression test, and water stability test are measured;

[0028] Step S3: The pressure filtration mud cake is cut into pieces with a clumping material shredder, and the large soil blocks are stirred to form uniform soil material, which is stacked in a collection tank;

[0029] Step S4: After the soil material is transported to the construction site, it is spread on the soil material, and the curing agent mixed uniformly from the blast furnace slag powder, gypsum powder, superabsorbent resin, and non-ionic polyacrylamide is evenly spread on the soil material. The road mixer is used for loosening and mixing several times to obtain a mixture of soil material and composite curing agent;

[0030] Step S5: On the basis of the mixture, a layer of soil material is spread, and a layer of quicklime is evenly spread on the basis of the soil material, and the road mixer is used for uniform mixing;

[0031] Step S6: Fill material stirring, spreading, and compaction, using a 25t road roller for multiple times of rolling to achieve the required compaction degree of the fill material, ensuring no wheel marks on the road surface;

[0032] Step s7: Roadbed finishing and shaping, using a level gauge, a line and a ruler to check the elevation and flatness, and adjusting the roadbed to the required shape;

[0033] Step s8: After each construction section is completed and the compaction degree is checked and qualified, the corresponding plastic film is spread on the road surface for maintenance;

[0034] Step s9: Quality acceptance, after the maintenance is completed, the core of the formed base layer is taken for testing the compaction degree, strength, and water content.

[0035] The components in the composite curing agent and the percentage of the soil body mass are as follows: blast furnace slag accounts for 6% to 8% of the soil body mass, quicklime accounts for 3% to 5% of the soil body mass, gypsum powder accounts for 1% to 2% of the soil body mass, superabsorbent resin accounts for 0.1% to 0.2% of the soil body mass, and polyacrylamide accounts for 0.2% to 0.4% of the soil body mass.

[0036] Example 4

[0037] A site filling construction process using a composite curing agent, including the following steps:

[0038] Step S1: Before construction, the current ground elevation of the road centerline is surveyed and checked with the design longitudinal section. After the road center stake is measured and set, the fill roadbed boundary is measured and set according to the design drawings, and the road elevation control stake is measured and set according to the road stake number;

[0039] Step S2: Fill material testing and analysis, composite curing agent includes blast furnace slag, quicklime, gypsum powder, non-ionic polyacrylamide, superabsorbent resin, and the pressure filtration mud cake is mixed with the composite curing agent for design, and the water content, liquid plastic limit, maximum dry density, unconfined compression test, and water stability test are measured;

[0040] Step S3: The pressure filtration mud cake is cut into pieces with a clumping material shredder, and the large soil blocks are stirred to form uniform soil material, which is stacked in a material collecting tank;

[0041] Step S4: The soil material is transported to the construction site and spread, and the curing agent mixed uniformly from slag powder, gypsum powder, superabsorbent resin, and non-ionic polyacrylamide is uniformly spread on the soil material, and the road mixer is used for multiple times of loosening and mixing to obtain a mixture of soil material and composite curing agent;

[0042] Step S5: On the basis of the mixture, a layer of soil material is spread, and a layer of quicklime is uniformly spread on the basis of the soil material, and the road mixer is used for uniform mixing;

[0043] Step S6: Fill material stirring, spreading and recompaction, multiple times of rolling with a 25t road roller to achieve the required compaction degree of the fill material to ensure that there is no wheel trace on the road surface;

[0044] Step s7: Roadbed finishing and shaping, using a level gauge, a line and a ruler to check the elevation and flatness, and the roadbed is finished and shaped;

[0045] Step s8: After each construction section is rolled and the compaction degree is checked and qualified, the corresponding plastic film is spread on the road surface for maintenance;

[0046] Step s9: Quality acceptance, after maintenance, the formed base is cored to test the compaction degree, strength, and water content.

[0047] The components in the composite curing agent and the percentage of the soil body mass are as follows: blast furnace slag accounts for 8% of the soil body mass, quicklime accounts for 4.4% of the soil body mass, gypsum powder accounts for 2% of the soil body mass, superabsorbent resin accounts for 0.2% of the soil body mass, and polyacrylamide accounts for 0.4% of the soil body mass.

[0048] The unconfined compressive strength of the existing roadbed filler standard curing for 7 days reaches 2490kPa, the unconfined compressive strength of the solidified soil standard curing for 7 days and curing for 1 day after being soaked in water can reach 2250kPa, the effect of the solidifying agent such as cement, lime, fly ash and the like is generally 0.6 or less; and the strength (7-day age) of the composite solidifying formula in the application, which adopts 8% of blast furnace slag of the soil body quality, 4.4% of quicklime of the soil body quality, 2% of gypsum of the soil body quality, 0.4% of non-ionic polyacrylamide of the soil body quality, and 0.2% of superabsorbent water-absorbing resin of the soil body quality, can reach 2490kPa, the water stability coefficient after curing for 7 days and soaking in water for 1 day reaches 0.9 or more, which is better than 0.6 of the solidifying agent such as cement, lime, fly ash and the like; and further effectively improves the water stability and service life of the roadbed structure after being eroded by water.

[0049] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, and which is based on the technical essence of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. A construction process of on-site filling with composite curing agent, specifically as follows: Step S1: Before construction, the current ground elevation of the road centerline is surveyed and checked with the design profile. After the road center stake is measured, the filling roadbed boundary is measured according to the design drawing, and the road elevation control stake is measured according to the road stake number; Step S2: Filling material test analysis, the composite curing agent includes blast furnace slag, quicklime, gypsum powder, non-ionic polyacrylamide, and superabsorbent resin. The components in the composite curing agent and the percentage of the soil mass are as follows: blast furnace slag accounts for 6-8% of the soil mass, quicklime accounts for 3-5% of the soil mass, gypsum powder accounts for 1-2% of the soil mass, superabsorbent resin accounts for 0.1-0.2% of the soil mass, and polyacrylamide accounts for 0.2-0.4% of the soil mass. The pressure filtration mud cake is combined with the composite curing agent, and the water content, liquid-plastic limit, maximum dry density, unconfined compression test, and water stability test are measured; Step S3: The pressure filtration mud cake is cut into pieces with a clumping material crusher, and the large soil blocks are stirred to form uniform soil material, which is stacked in a collection tank; Step S4: The soil material is transported to the construction site for paving. The curing agent mixed uniformly from slag powder, gypsum powder, superabsorbent resin, and non-ionic polyacrylamide is evenly spread on the soil material, and the road mixer is used for multiple times of loosening and mixing to obtain a mixture of soil material and composite curing agent; Step S5: On the basis of the mixture, a layer of soil material is paved, and a layer of quicklime is evenly spread on the basis of the soil material, and the road mixer is used for uniform mixing; Step S6: Filling material mixing, paving, and recompaction, multiple times of rolling with a 25t road roller to achieve the required compaction degree of the filling material, ensuring no wheel marks on the road surface; Step S7: Roadbed finishing and shaping, using a level gauge, a line and a ruler to check the elevation and flatness, and trimming and shaping the roadbed; Step S8: After each construction section is rolled and the compaction degree is checked and qualified, the corresponding plastic film is paved on the road surface for maintenance; Step S9: Quality acceptance, after maintenance, the formed base is cored to test the compaction degree and strength, and the water content.

2. The in-place fill construction process with composite curing agent of claim 1, wherein: The components in the composite curing agent and the percentage of the soil mass are as follows: blast furnace slag accounts for 8% of the soil mass, quicklime accounts for 4.4% of the soil mass, gypsum powder accounts for 2% of the soil mass, superabsorbent resin accounts for 0.2% of the soil mass, and polyacrylamide accounts for 0.4% of the soil mass.

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