A kind of evaluation method of slag as aggregate stability
Technical field
The invention belongs to field of material technology, and in particular to a kind of evaluation method of slag as aggregate stability.
Background technique
With the fast development of China's steel and iron industry, slag as aggregate is annual as the byproduct generated in steelmaking process
Yield is up to 100,000,000 tons or more, however the utilization rate of China's slag as aggregate only only has 30%, and steel slag volume of cargo in storage is every year with tens million of
The increased number of ton, the bulk deposition of steel slag cause serious pollution to environment.If steel slag is handled and is comprehensively utilized not in time,
More and more soils can be occupied, environment is polluted, causes the waste of resource, while influencing the sustainable development of steel and iron industry.
Domestic and international correlative study shows that slag as aggregate has good physical and mechanical properties, as hardness is high, density is big, strong
Degree is high, polishing value is high, graininess is good etc..And slag as aggregate belongs to alkali aggregate, and it is good with the adhesiveness of pitch.With state, China
People's rapid development of economy drives the continuous improvement of living standards of the people, and the highway people's livelihood engineering important as one obtains
Quickly development.What asphalt concrete road faced to gather materials is in great demand, at present the used mainly limestone that gathers materials
With basalt etc. is high-quality gathers materials, however the natural aggregate of this kind of non-renewable resources has been in the state that supply falls short of demand, uses steel
Slag aggregate substitution it is natural it is high-quality gather materials after, can be well solved the problem of high-quality natural aggregate shortage in recent years.
The main problem that limitation slag as aggregate uses at present is that its volume stability is poor.In steelmaking process, lime conduct
Slag making materials are put into converter, and in the initial stage of smelting or low alkalinity clinker, lime particle and acidic oxide are combined into stabilization
Mineral facies float on molten steel surface, thus achieve the purpose that remove impurity improve quality of molten steel, with addition lime solubility by
Gradually in saturation, making steel the later period has put into excessive lime, and the primary lime of these non-scorification and in melt cinder crystallization time
Quick lime is the main source that free calcium oxide is formed in slag as aggregate.Wherein part that not sufficiently dissolved lime is formed
F-CaO structure is comparatively dense, and aquation is very slow.And gather materials the lime of middle precipitation from molten steel slag, in annealing process, in warm sludge
C3S is extremely unstable, is changed into C at 1250 DEG C -1100 DEG C2S and f-CaO is mainly trapped in slag as aggregate surface, part f-
CaO is the main reason for causing slag as aggregate unstable.
Since the presence of labile element in slag as aggregate produces during road surface is on active service by its volume of rain drop erosion
Raw expansion, the friction in vehicle travel process at the same time, effect of impact lead to its further cracking destruction, so slag as aggregate
It needs to evaluate its stability before use.China is directed to the main evaluation method of slag as aggregate volume stability at present
There are two types of, one of method is evaluated using the pressure steaming rate index of slag as aggregate, another is then measurement steel slag
F-CaO content contained in gathering materials is evaluated.But when evaluating using former approach, kettle is steamed using pressure to measure pressure steaming
Friction and the influence of effect of impact are not accounted for when rate.Simultaneously after use a kind of method evaluate when be difficult to differentiate between f-CaO and
Ca (OH) 2 causes measured value to be greater than true value.
Therefore, it is necessary to which Service Environment actual conditions can more be reflected by finding one kind, and simplicity, Fast Evaluation slag as aggregate are steady
Qualitative method accurately and effectively assesses the stability of slag as aggregate.
Summary of the invention
It is an object of that present invention to provide a kind of easy, Fast Evaluation slag as aggregate stability methods, thus more accurate
The stability of slag as aggregate is quickly determined, effectively to control the quality of slag as aggregate.
In order to achieve the above objectives, as follows using technical solution:
A kind of evaluation method of slag as aggregate stability, comprising the following steps:
1) the slag as aggregate sample that particle size range is 2.36-4.75mm is screened out first, in accordance with grade;
2) Los Angeles Abrasion Test is directly carried out to gained slag as aggregate sample, obtains Los Angeles abrasion retention rate y%;
3) by fitting formula y=120.66-5.7343x, it is calculated 9d water bath with thermostatic control treated Los Angeles abrasion
Retention rate decreasing value x%;
4) abrasion retention rate decreasing value in slag as aggregate sample Los Angeles is less than or equal to be determined as that slag as aggregate is steady when 5%
It is fixed, it is determined as that slag as aggregate is unstable when greater than 5%.
According to the above scheme, step 1 is according to the correlation of T0302 in " highway engineering gather materials testing regulations " (JTGE42-2005)
Step requires to screen out the slag as aggregate sample to be measured that particle size range is 2.36-4.75mm.
According to the above scheme, step 2 is according to the correlation of T0317 in " highway engineering gather materials testing regulations " (JTGE42-2005)
Step requires to carry out Los Angeles Abrasion Test.
According to the above scheme, the specific requirement of the Los Angeles Abrasion Test are as follows: slag as aggregate sample mass be 2500 ±
10g, steel ball gross mass are 2500 ± 25g, and it is 500r that Los Angeles abrasion machine, which rotates all numbers, rotative speed control 30r/min~
33r/min。
According to the above scheme, the specific heating temperature of the water bath with thermostatic control is 70~80 DEG C.
Beneficial effect is as follows compared with the existing technology by the present invention:
The present invention provides a kind of evaluation method of slag as aggregate stability, is not necessarily to by Los Angeles Abrasion Test to steel slag collection
Various labile elements are measured respectively in material, directly can wear away retention rate by untreated slag as aggregate Los Angeles to count
Calculate the stability that its retention rate decreasing value size of Los Angeles abrasion before and after the processing determines slag as aggregate sample, evaluation method behaviour
Make simply, data are reliably convenient for analyzing.
The present invention provides a kind of evaluation method of slag as aggregate stability, which had both considered slag as aggregate and existed
Keep its unstable by rainwater weathering during pavement usage, and simulates the friction in vehicle travel process and effect of impact
Influence.
Detailed description of the invention
Fig. 1 slag as aggregate Los Angeles wears away retention rate with the variation relation of water bath with thermostatic control processing time
Fig. 2 slag as aggregate estimation of stability linear fit relationship
Specific embodiment
Following embodiment further illustrates technical solution of the present invention, but not as limiting the scope of the invention.
Take three kinds of separate sources, the slag as aggregate of different disposal technique is denoted as A, B and C respectively, chemical component such as the following table 1
It is shown:
Table 1
Equipment uses HHW21-600 type constant water bath box, DM-II type Los Angeles machine.
Embodiment
It is required according to the correlation step of T0302 in " highway engineering gather materials testing regulations " (JTG E42-2005) by steel slag collection
It is stand-by for the slag as aggregate sample of 2.36-4.75mm that material uses standard square hole screen to screen out particle size range.
(1) the 1st group of slag as aggregate is mainly tested as follows: each slag as aggregate is respectively weighed 2 parts, every part of quality is
2500g requires to carry out Los Angeles according to the correlation step of T0317 in " highway engineering gather materials Experimental Procedures " (JTG E42-2005)
Abrasion test.The parameter setting of test is specially that all numbers of machine rotation are 500r, and steel is added in 30r/min in rotative speed control
Ball quality is 2500g, and about 4-5 is a.It after Los Angeles Abrasion Test, needs to sieve slag as aggregate again, record sieve
Divided data, and calculate slag as aggregate Los Angeles abrasion retention rate.
Calculation formula are as follows:Wherein, Pi is that slag as aggregate Los Angeles wears away retention rate, %;Mi is raw steel slag collection
The mesh screen of material partial size is improved quality, g;M is the gross mass for testing slag as aggregate sample used, g.Calculated result is as shown in table 2.It should
Experimental result represents abrasion and the jolt capacity of the anti-vehicular load of slag as aggregate.
(2) water bath with thermostatic control immersion treatment, specific heating condition are carried out to the 2nd group of slag as aggregate are as follows: temperature holding 70~
80 DEG C, the time takes 3,6,9 and 12 days.
Slag as aggregate after water bath with thermostatic control immersion treatment is required to be heated to constant weight in 105 DEG C of baking oven.
Each slag as aggregate Jing Guo different disposal duration is respectively weighed 2 parts, every part of quality is 2500g, according to " highway
Engineering is gathered materials Experimental Procedures " correlation step of T0317 requires to carry out Los Angeles Abrasion Test in (JTG E42-2005).Test
Parameter setting after Los Angeles Abrasion Test, needs to sieve slag as aggregate again with the 1st group, records size data,
And slag as aggregate Los Angeles abrasion retention rate is calculated, calculated result is as shown in table 2.
Table 2
According to the data of table 2, slag as aggregate A is drawn out, Los Angeles abrasion retention rate of B, C handle the time with water bath with thermostatic control
Situation of change it is as shown in Figure 1.As shown in Figure 1: three kinds of slag as aggregate, under the water bath with thermostatic control effect of natural wind simulating, with
Processing the time extension, Los Angeles abrasion retention rate show the trend gradually decreased.In the constant temperature Jing Guo same time
Los Angeles abrasion retention rate of the slag as aggregate B of water bath processing is maximum, and slag as aggregate C takes second place, and slag as aggregate A is minimum.But three
Its Los Angeles abrasion retention rate changes less when kind slag as aggregate is handled 6 to 12 days by water bath with thermostatic control, shows slag as aggregate
Internal labile element has been cleared up substantially, and slag as aggregate tends towards stability state.In order to ensure the accuracy of the evaluation method, this hair
It is bright that Los Angeles at water bath with thermostatic control processing 9 days is selected to wear away retention rate as evaluation criterion.Steel slag after can learning 9d by table 2
Gather materials A, and Los Angeles abrasion retention rate of B and C are respectively 73.09%, 88.21% and 78.98%, and Los Angeles wears away retention rate phase
6.92%, 4.77% and 6.38% is reduced respectively than untreated slag as aggregate.
Since variety classes steel slag is in Los Angeles abrasion retention rate value difference after water bath with thermostatic control handles 9d, so it becomes
Standard when stablizing is just different, i.e. none unified standard.But it can be seen that the Lip river after water bath with thermostatic control handles 9d
There is reversed related passes between the two for Shan Ji abrasion retention rate decreasing value and untreated steel slag Los Angeles abrasion retention rate value
System, i.e., untreated slag as aggregate Los Angeles abrasion retention rate is higher, and retention rate decreasing value is smaller when tending towards stability.So this hair
The bright linear fit relationship using the two carries out united analysis to Los Angeles abrasion retention rate, to pass through Los Angeles Abrasion Test
To evaluate the stability of variety classes slag as aggregate.Linear fit relationship is shown in Fig. 2.Fit correlation formula such as formula (1):
Y=120.66-5.7343x R2=0.9683 (degree of fitting of the linear relationship, the value show to be fitted closer to 1
Degree is better, and correlation is stronger) (1)
In formula:
Y --- untreated steel slag Los Angeles wears away retention rate, %;
Steel slag Los Angeles wears away retention rate decreasing value, % after x --- water bath with thermostatic control handles 9d.
Steel slag Los Angeles abrasion retention rate is higher, and slag as aggregate stability is better, becomes after 9d water bath with thermostatic control processing
Retention rate decreasing value when stablizing is also smaller.Therefore it can be by testing untreated slag as aggregate Los Angeles abrasion retention rate (y)
Above-mentioned fitting formula (1) is brought into come steel slag Los Angeles abrasion retention rate decreasing value (x) when determining that it tends towards stability.Due to steel slag collection
Material requires its free calcium oxide content not higher than 3% when in use, and the free calcium oxide content of the slag as aggregate B chosen is
2.91%, it tends towards stability near unstable critical value, slag as aggregate A and C are respectively that 3.86% and 3.29% are above
3%.Therefore it is worn away referring to Los Angeles of slag as aggregate B and retains decreasing value 4.77% to determine that estimation of stability standard, the present invention take x
=5%.It is determined as that slag as aggregate is unstable when i.e. x value is greater than 5%, x is less than or equal to be determined as that slag as aggregate is stablized when 5%.
In conclusion the present invention provides a kind of evaluation method of slag as aggregate stability, can directly be worn away by Los Angeles
Slag as aggregate Los Angeles abrasion retention rate (y) bring formula (1) into and calculate whether x value is greater than 5% to determine slag as aggregate after test
The stability of sample, without being measured respectively to labile elements various in slag as aggregate, easy to operate, data are reliably convenient for
Analysis, while simulating variety classes steel under the friction in vehicle travel process and effect of impact and natural environment slacking
The stability of slag aggregate, so the present invention is suitble to promote and apply in actual production.
Theory of the invention is only illustrated in above-described embodiment, and is not intended to limit the present invention.It is any to be familiar with this technology
Personage without departing from the spirit and scope of the present invention, carry out modifications and changes to above-described embodiment.Therefore, Ju Fansuo
Belong to all for having usually intellectual in technical field and being completed without departing from the spirit and technical ideas disclosed in the present invention
Equivalent modification or change should be covered by the claims of the present invention.