CN104860554B - The composite base material of slag room temperature reconstruct preparation foundation stabilization - Google Patents

Abstract

The present invention is the NEW TYPE OF COMPOSITE base material of slag room temperature reconstruct preparation foundation stabilization, belongs to the technical field of basement process in Communication and Transportation Engineering and civil engineering；The NEW TYPE OF COMPOSITE base material of slag room temperature reconstruct preparation foundation stabilization, it is characterised in that: in slag, add metakaolin and Calx, Con trolling index respectively: control SM between 2 ~ 2.4；IM is between 1.2 ~ 1.6, and KH is between 0.9 ~ 0.94, after having configured mixture, according to this water requirement sample preparation, puts into standard curing room, sample preparation.After being reconstructed by slag according to cement proportion, the composition of slag is made up and is supplemented, and is significantly improved in early days in intensity, it is possible to greatly reduce cost.

Description

The composite base material of slag room temperature reconstruct preparation foundation stabilization

Technical field

The present invention is the NEW TYPE OF COMPOSITE base material of slag room temperature reconstruct preparation foundation stabilization, is that one utilizes metakaolin, ripe Calx, a small amount of composite high-early strength water reducer, excite the composite reactive base material of slag at normal temperatures, belong to Communication and Transportation Engineering and building The technical field of basement process in engineering.

Background technology

Cut-off reaches about 8.3 hundred million tons to crude steel yield in 2012, accounts for about the 50% of Gross World Product.At present, China's slag produces Amount accounts for the 15～20% of crude steel yield, there are about 100,000,000～1.5 hundred million tons of slags the most every year and produces and output along with crude steel.But China's steel slag utilization rate, but less than 25%, has big steel slag to be not used the most every year, cause soil to be contaminated, soil micro- Biota suffers the problems such as destruction, body of groundwater pollution.

Slag is a kind of material with potential gelling, is mainly CaO, SiO in its slag chemical composition₂, and on a small quantity Al₂O₃, Fe₂O₃, MnO equal size fluctuating margin bigger；The essential mineral composition of mineralogical composition mainly slag has tricalcium silicate (C₃S), dicalcium silicate (C₂S), RO (solid solution that R represents magnesium, ferrum, the oxide of manganese are formed), free lime (free CaO； F-CaO) etc..Due to C in slag₂S accounts for 30～60%, and C₃S content is but only less than 20%, and therefore slag hydration rate ratio is general Logical portland cement is the most many, is usually used to do roadbed filling, aggregate, asphalt aggregate use, and past Toward not using slag as making Binder Materials use.Inside its reason mainly slag, activity is more difficult ejects, its early water Change degree is low, shows as early strength low.

On the other hand, existing slag reconfiguration technique is to add to adjust material (aluminum matter, siliceous and calcareous material) in slag, Make it that chemical reaction at high temperature to occur, absorb f-CaO, and generate active mineral C₂S、C₃S and C₃A etc., improve the gelling of slag Activity.Existing slag reconfiguration technique specifically includes that front end reconstruct and rear end reconstruct.Front end reconstruct refers under keeping high temperature to steel Add modulator in slag, slag component is adjusted；Rear end reconstruct refers to mix at normal temperatures modulator, the most at high temperature forges Cool down after burning a period of time, reach the purpose that slag component is adjusted.Two kinds of reconfiguration techniques can make the slag after reconstruct Composition is similar to cement, but is directed to hot conditions, relatively costly, is not directly applied for Communication and Transportation Engineering and building work As soil body firming agent in basement process in journey.Meanwhile, hot conditions reconstruct slag needs to consume substantial amounts of electric energy, heat energy, disappears Consumption mass energy, to environmental conservation, reduces CO2 emission unfavorable.

From Appropriate application material with given play to material maximum performance angularly under the suitable conditions, need slag Reconfiguration technique at room temperature excites making up of activity of steel slag.Conventional slag alkali-activator has Gypsum Fibrosum, grog, Calx With alkali-metal silicate, carbonate or hydroxide etc..Metakaolin is a kind of activity geopolymer, is to be former with Kaolin Material, the anhydrous aluminium silicate (Al that (600 DEG C～900 DEG C) are formed through dehydration at a proper temperature₂O₃·2SiO₂, AS₂).Higher ridge Soil can be inspired its activity, the most so-called pozzolanic activity, system during kaolin calcined under alkaline environment Free energy raise, structural stability reduce, Al-O structure occur restructuring thus show activity.In materials'use, often Needing to add compound additive in material and meet the actually used demand of material, these additives generally have water reducer, morning strong Agent, air entraining agent etc..

For this present invention with Calx and metakaolin as raw material, with composite high-early strength water reducer as additive, it is suitable to seek Proportioning, form the compound reconstruct base material that can excite slag under room temperature.

Summary of the invention

Technical problem: be high-temperature reconstruction technology for current slag reconfiguration technique, it is impossible to direct applied in engineering Problem, will be added in slag containing the metakaolin of activity, and is added thereto to alkali-activator and early strength water-reducing agent, is formed multiple Close reconstruct base material, reach on chemically composition, to supply slag and the difference on Portland cement, excite the potential gelling of slag Property, promote slag overall utilization rate, save the energy and reduce the purpose of CO2 emission.

Technical scheme: according to the rate value scope of Portland cement, adds metakaolin and Calx in slag, makes The chemical composition of mixture is similar in Portland cement.Con trolling index is respectively:

1. silicon rate (Silica Modulus, SM) SM=SiO₂/(Al₂O₃+Fe₂O₃)

2. aluminum rate (Iron Modulus, IM) IM=Al₂O₃/Fe₂O₃

3. lime saturation factor (Lime Saturation Coefficient, KH)

$\mathrm{KH}=\frac{(\mathrm{CaO}-1.65{\mathrm{Al}}_2{O}_3-0.35{\mathrm{Fe}}_2{O}_3)}{2.8{\mathrm{SiO}}_2}$ (when IM >=0.64)

$\mathrm{KH}=\frac{(\mathrm{CaO}-1.1{\mathrm{Al}}_2{O}_3-0.7{\mathrm{Fe}}_2{O}_3)}{2.8{\mathrm{SiO}}_2}$ (when IM < when 0.64)

Control SM between 2～2.4；IM is between 1.2～1.6, and KH is between 0.9～0.94.Configure mixture After, add water sample preparation according to normal consistency water requirement, at standard curing box.

Beneficial effect: after being reconstructed by slag according to cement proportion, the composition of slag is made up and supplements, the most by force It is significantly improved on degree.Do not add metakaolin, 3 days unconfined compressive strengths of slag of Calx are 0.3MPa, within 7 days, resist without lateral spacing Compressive Strength is 1.6MPa, and 28 days unconfined compressive strengths are 18.4MPa；And the 3 days non-confining strengths of slag after reconstruct Degree for 2.5MPa～5.9MPa, 7 days unconfined compressive strengths are 5.4MPa～11.8MPa, and within 28 days, unconfined compressive strength is 19.6～25.4MPa.From the point of view of the change of unconfined compressive strength, the early stage reconstructing slag after mixing metakaolin, Calx is strong Degree is enhanced, and later strength increase rate is less.Slag after reconstruct can preferably ensure project progress and safety.

Due to the difference of steel manufacturing process, pretreatment of slag technique etc., cause slag difference on composition, therefore The Activiation method in past tends not to enough be replicated, and does not has same standard.Employing rate value method, reconstructs slag, it is possible to unification goes out The formula that slag activates in room temperature reconstruct, is a kind of method that can be expanded.

At present, the price of slag is uneven on the market, and test slag used is the product after wet magnetic separation, the market price It is about 50 yuan/ton.In addition the Calx market price is about 150 yuan/ton, and metakaolin is about 400 yuan/ton, and cement price is about 450 yuan/ton.The slag gone out according to proportion design accounts for 31%, and Calx accounts for 60%, and metakaolin accounts for 9%, then with one ton Calculate the slag after this reconstruct and be about 138 yuan/ton, although exceed 2.8 times than slag price, but be but only cement valency The 30% of lattice, it is possible to greatly reduce cost.

Detailed description of the invention

Selection specific surface area is 300m²/ g～500m²Slag between/g, and it is carried out chemical composition test, utilize and survey Test result compares with cement composition, is added thereto to metakaolin, Calx.Add fashionable, the composition of material after should controlling to mix Meet cement rate value requirement.Control SM between 2～2.4；IM is between 1.2～1.6, and KH is between 0.9～0.94.The strongest Water reducer selects SEU type to compound early strength water-reducing agent, and its proportioning is shown in Table 2, and the incorporation of early strength water-reducing agent is 2%.

Example: the slag after selecting Jiaxing Area to carry out wet magnetic separation, its chemical composition is shown in Table 1:

Table 1 slag chemical composition (mass fraction)

CaO	Al2O3	SiO2	Fe2O3	MgO
					49.83～55.46	4.77～4.82	28.47～34.28	10.19～14.17	2.17～5.83

Table 2 SEU type compounds early strength water-reducing agent match ratio

Material name	Mass ratio	Material name	Mass ratio
				Anhydrous sodium sulfate	12	Sodium nitrite	2
NF naphthalene series high-efficiency water-reducing agent	8	Wollastonite in powder	29.4
				Triethanolamine	0.6	Flyash (2 grades)	48

According to the regulation of " steel-making slag powder in cement and concrete " (GB/T20491 2006), slag is passed through The sieve of 0.9mm, screen over-size is less than 0.5%.Test slag normal consistency water requirement is 0.23, according to this water requirement sample preparation, puts Enter form removal after standard curing room (20 DEG C, 90% ± 4%) maintenance one day, standard curing to age, survey its 3 days, 7 days and 28 days Unconfined compressive strength value.Result is as shown in table 2.After result shows to mix metakaolin, Calx and a small amount of early strength water-reducing agent, energy Enough significantly improve the early strength of slag, promote slag aquation, slag later strength is also had certain contribution simultaneously.3 days intensity Improve nearly 20 times, and 7 days intensity also improves 7 times, the superiority after embodying incorporation, slag activation effect stimulated.

Table 2 result of the test

Claims (3)

1. the composite base material of slag room temperature reconstruct preparation foundation stabilization, it is characterised in that: in slag, add metakaolin and ripe Calx, Con trolling index respectively:

Silicon rate SM=SiO₂/ (Al₂O₃+Fe₂O₃)

Aluminum rate IM=Al₂O₃/Fe₂O₃

Lime saturation factor KH

KH=, when IM >=0.64；

KH, when IM is < when 0.64；

Control SM between 2 ~ 2.4；IM is between 1.2 ~ 1.6, and KH is between 0.9 ~ 0.94, and mixes the morning that mass ratio is 2% Strength water-reducing agent, after having configured mixture, according to this water requirement sample preparation, puts into standard curing room, sample preparation finished product.

The composite base material of slag room temperature the most according to claim 1 reconstruct preparation foundation stabilization, it is characterised in that described Slag be specific surface area be 300m²/kg~500m²Steel-making slag powder between/kg, slag: Calx: the mass ratio of metakaolin exists 26 ~ 36:55 ~ 64:7 ~ 10.

The composite base material of slag room temperature the most according to claim 1 reconstruct preparation foundation stabilization, it is characterised in that described Early strength water-reducing agent proportioning is: according to the mass fraction:

Anhydrous sodium sulfate 12 parts, sodium nitrite 2 parts, NF naphthalene series high-efficiency water-reducing agent 8 parts, wollastonite in powder 29.4 parts, triethanolamine 0.6 Part, 2 grades 48 parts of flyash.