Non-metallic mineral grouting material for reinforcing road subgrade
Technical Field
The invention relates to the technical field of grouting materials for reinforcing a road subgrade, in particular to a non-metallic mineral grouting material for reinforcing the road subgrade.
Background
The grouting material for reinforcing the roadbed used in the current market is mainly prepared by taking a cement base as a main material, assisting with some additives and blending admixtures, and the roadbed belongs to underground concealed engineering, the underground base material and the geographic structure of the roadbed are complex and changeable, but the traditional grouting material has poor adaptability, is usually good in using effect in a certain area or a certain road section, but has no effect when used in a changed area or road section, and causes serious reworking and waste phenomena.
The reason for the failure of the roadbed is various, and the most important of the reasons are: the traditional grouting material can not immediately form a wrapping material for fixing a roadbed loose material in a complex underground environment (particularly a water environment and sometimes a dynamic water environment) so as to generate strength, and the traditional grouting material is often lost and dispersed along with underground water or can not be solidified with underground argillaceous materials to form a reinforcing effect. Therefore, the roadbed reinforcement is similar to a dummy roadbed and does not play any role.
Disclosure of Invention
In order to overcome the defects of the traditional grouting material, the invention aims to provide the non-metallic mineral grouting material for reinforcing the road bed, which has a water squeezing function, wide compatibility with a foundation material of the road bed, high strength generated by penetration, wrapping and squeezing, good construction performance and wide adaptability.
In order to solve the technical problem, the invention aims to realize that:
the invention relates to a non-metallic mineral grouting material for reinforcing a road subgrade, which comprises 50-60 parts by weight of calcined kaolin, 20-30 parts by weight of blast furnace slag powder, 10-20 parts by weight of double-flying powder and an additive; the additive comprises a water-fixing and coagulation-maintaining agent, a softening agent and a flatting agent; the water-fixing and coagulation-keeping agent is cellulose ether which contains 23-65 wt% of hydroxypropoxyl and 16.5-20 wt% of methoxyl, the ash content is less than or equal to 1.0%, the water content is less than or equal to 3.0%, and the gel temperature is 60-70 ℃.
As further illustration of the above scheme, the additive is used in an amount of 0.3 to 1 part by weight.
As further illustration of the above scheme, the solid-water coagulant is used in an amount of 0.1 to 0.3 parts by weight; the using amount of the softening agent is 0.1-0.6 part by weight; the using amount of the flatting agent is 0.1-0.2 weight part.
The invention has the beneficial effects that: the invention relates to a non-metallic mineral grouting material for reinforcing a road subgrade, which comprises calcined kaolin, blast furnace slag powder, fly ash, a water-fixing and coagulation-maintaining agent, a softening agent and a leveling agent. The hydraulic solidification mineral substance, the double flying powder and the industrial waste residue are adopted and are supplemented with the additive, only water is needed to be added for stirring when the cement mortar is used, the cement mortar has the characteristics of high early strength, good injection fluidity, high density after the solidified slurry is formed, and the like, can effectively improve the mechanical compression strength of the road foundation, and has the remarkable characteristics of good water damage resistance, high durability and the like.
Detailed Description
The present invention is further illustrated by the following specific examples.
Example one
The embodiment relates to a non-metallic mineral grouting material for reinforcing a road subgrade, which is prepared by preparing calcined kaolin and blast furnace slag into powder. Then adding the powdery calcined kaolin, the blast furnace slag powder, the double-flying powder and the additive into a dry mixing stirrer according to the weight ratio, mixing and stirring for about 15 minutes to obtain uniform dry powder, and packaging and warehousing. The 100 mesh passage rate of the prepared powder was 99%.
The main chemical components of the selected calcined kaolin are silicon dioxide, ferric oxide and aluminum oxide. The main chemical component of the selected double flying powder is calcium carbonate.
The selected blast furnace slag is industrial waste material of blast furnace steel making, the commercially available S95 granulated blast furnace slag has a density of 2.86 g per cubic centimeter and has the main chemical components of calcium oxide, silicon dioxide and aluminum oxide, and the chemical components are shown in the following table:
chemical composition
|
Al2O3 |
SiO2 |
CaO
|
Fe2O3 |
MnO
|
P2O5 |
MgO
|
TiO2 |
LOI
|
Content/%
|
14.82
|
33
|
40.8
|
0.23
|
0.32
|
0.01
|
7.85
|
0.66
|
2.31 |
The non-metallic mineral grouting material in the embodiment comprises: 50 parts by weight of calcined kaolin, 20 parts by weight of blast furnace slag powder, 10 parts by weight of fly ash and 0.3 part by weight of additive; the used additives comprise a water-fixing and coagulation-maintaining agent, a softening agent and a leveling agent. In this embodiment, the softening agent is polymer powder 6034, and the leveling agent is PEG 8010.
The water-fixing and coagulation-maintaining agent used in this example is HPMC (cellulose ether) 400F developed by this company, and the specific chemical name and composition of HPMC (cellulose ether) are as follows:
the chemical name is Hydroxypropylmethyl Celulose.
Components
|
Content (wt.)
|
Hydroxypropoxyl radical wt%
|
23-32
|
Methoxy group wt.%
|
16.5-20
|
Ash content wt%
|
≤1.0
|
Water content wt%
|
≤3.0
|
Gel temperature C
|
60-70 |
The added additive ensures that the dry powder material has fluidity when being added with about 30 percent of water, keeps a solid flowing state in a water environment to squeeze water away (water squeezing property), permeates into gaps of the loose roadbed material to wrap the surface of the loose roadbed material to form a whole body, generates strength and plays a role in increasing and reinforcing the roadbed.
The cellulose ether is a cellulose derivative obtained by reacting cellulose from wood and cotton with caustic soda and etherifying the cellulose with an etherifying agent. Has thickening effect, and can increase the dispersion resistance and homogeneity of slurry body, and prevent material layering and segregation. When the cellulose ether is dissolved in water, the hydroxyl and the oxygen atoms on the ether bonds are associated with water molecules to form hydrogen bonds, so that free water becomes bound water, and the cellulose ether has certain water retention capacity, can prevent the substrate from excessively and quickly absorbing water and hindering the evaporation of the water, and ensures that the substrate has enough water when hydrated. The cellulose ether has both hydrophilic and hydrophobic groups, is a surfactant, and can increase the binding capacity between the grouting material and the soil particles,
the content of hydroxypropoxyl groups in cellulose ether affects the performance of the cellulose ether. The cellulose ether includes low-substituted 2-hydroxypropyl ether cellulose and high-substituted 2-hydroxypropyl ether cellulose. The content of hydroxypropoxyl in the low-substituted 2-hydroxypropyl ether cellulose is 7-16 percent, and the content of hydroxypropoxyl in the high-substituted 2-hydroxypropyl ether cellulose is 60-66 percent. The content of hydroxypropoxyl groups in the cellulose ether selected in this example was 23 to 32 wt.%. Through the test, when selecting low substituted 2-hydroxypropyl ether cellulose, because the low flowing speed that makes the slip casting material that this embodiment relates of hydroxypropoxyl content is too fast, moreover because water retention is poor, its crowded water performance is not good, and the setting time is too short, can not be fine infiltration to the granule that needs the reinforcement, forms a whole for bonding strength is not enough. The highly substituted 2-hydroxypropyl ether cellulose is used, and the content of the hydroxypropoxyl group is high, so that the flow speed of the grouting material related to the embodiment is too low, and the grouting material has good water squeezing performance, but the permeability is poor, and the bonding strength is influenced.
The non-metallic mineral grouting material related to the embodiment enters the micro-gap through filling, permeation and compaction due to high fluidity and permeability, so that the road base and pavement diseases are repaired, and the overall strength of the pavement structure is enhanced.
The grouting material can permeate into soil particles after being dissolved with free water on the surface of the soil particles and react to generate an irreversible gel, so that a stable colloid structure is formed between different particles, the mode that the soil particles are combined with each other through combined water is changed, the grouting material gradually and the active mineral substances in the soil particles are subjected to chemical reaction, inert silicon dioxide and aluminum oxide in a base layer or soil can be activated, the nonmetal mineral substance grouting material and the base layer or the soil form a stone body, the structure is compact after the reaction, the bearing capacity of a road is improved, and the water scouring resistance is high.
Compared with other types such as cement-based grouting material and asphalt grouting material, the grouting material can excite part of active substances in a reinforced structure layer to generate a new inorganic polymer gel body while filling and wrapping gaps and particle interfaces of the reinforced soil body, and the reinforcing effect is enhanced by the grouting material in cooperation.
Further, the dosage of the solid-water coagulant aid is 0.1 part by mass, the dosage of the softening agent is 0.1 part by mass, and the dosage of the flatting agent is 0.1 part by mass.
Example two
The non-metallic mineral grouting material for road bed reinforcement in the embodiment is different from the first embodiment in that: the non-metallic mineral grouting material in the embodiment comprises 55 parts by weight of calcined kaolin, 25 parts by weight of blast furnace slag powder, 15 parts by weight of double-flying powder and 0.5 part by weight of additive.
Further, the dosage of the solid-water coagulant aid is 0.3 mass part, the dosage of the softening agent is 0.1 mass part, and the dosage of the flatting agent is 0.1 mass part.
EXAMPLE III
The non-metallic mineral grouting material for road bed reinforcement in the embodiment is different from the first embodiment in that: the non-metallic mineral grouting material in the embodiment comprises 60 parts by weight of calcined kaolin, 30 parts by weight of blast furnace slag powder, 20 parts by weight of fly ash and 0.8 part by weight of additive.
Further, the dosage of the solid-water coagulant aid is 0.4 mass part, the dosage of the softening agent is 0.2 mass part, and the dosage of the flatting agent is 0.2 mass part.
Example four
The non-metallic mineral grouting material for reinforcing the roadbed of the road according to the embodiment is different from the third embodiment in that: the amount of the water-fixing and coagulation-maintaining agent used was 0.6 part by mass.
The non-metallic mineral grouting materials of the first and fourth examples were compared with those of the first and second comparative examples. The comparative example one used was a cement-based grout and the comparative example two was an asphalt grout. The non-metallic mineral grouting material of the first embodiment and the fourth embodiment is added with about 30% of water, so that the grouting material of the dry powder head has fluidity after being uniformly mixed with the water.
The key factors determining the grouting reinforcement effect are the permeation and flow properties of the grouting material and the strength after hardening. The grouting material can fully fill the void area due to good permeability and fluidity, and the strength of the hardened grouting material is matched with the strength of the original pavement as much as possible, so that the reinforcing and reinforcing effects can be achieved, and secondary damage caused by uneven distribution of internal stress of a road structure layer under the action of traffic load due to the fact that the difference between the strength of a grouting material concretion body and the strength of the original pavement is too large can be avoided.
In the cement-based grouting material, the proportion of cement, water reducing agent, early strength agent and expanding agent is 1: 0.01: 0.1: 0.005-0.01. The cement grouting material has the problems of poor stability, easy precipitation, limited permeability and the like.
The geopolymer grouting material comprises a liquid A and a liquid B, wherein the liquid A is prepared by mixing steel slag, slag and fly ash according to the ratio of 1: 1 and then adding water. The liquid B is water glass, and the modulus of the water glass is 3.3. The grouting material can be well mixed with original road materials such as soil, slag stones and the like after being injected into the road, and is filled into gaps between the soil and the broken stones.
The materials of the experimental examples are detected, and the technical data are as follows:
the fracture ratio is the ratio of the compressive strength to the flexural strength, and lower means better flexibility of the anti-crack mortar.
As can be seen from the above table, the non-metallic mineral slurries prepared in examples one to three have high fluidity and permeability. And the water-squeezing performance is good through testing, so that the solid flowing state can be kept in a water environment, particularly a dynamic water environment, the construction performance is good, and the adaptability is wide. The non-metallic mineral substance grouting material in the first embodiment is particularly suitable for grouting reinforcement of loose subgrade and grouting reinforcement of void semi-rigid pavement, and the non-metallic mineral substance grouting material in the second embodiment is suitable for wandering reinforcement of subgrade, particularly deep reinforcement of water environment subgrade and grouting reinforcement of void semi-rigid pavement. The non-metallic mineral grouting material related to the third embodiment is suitable for grouting reinforcement of a rigid roadbed and simultaneously suitable for supplementing slurry for void of a rigid pavement. The problem of pavement cracking caused by different durability caused by combination of new and old materials can be avoided. The nonmetal mineral grouting material related to the fourth embodiment is generally applicable to the grouting and rush-repair projects of various pavements, such as rush-repair reinforcement of pavements, and early recovery of traffic (within 1 day).
The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.