CN1069956A

CN1069956A - Swelling agent for tuff

Info

Publication number: CN1069956A
Application number: CN 91108533
Authority: CN
Inventors: 张秀兰
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-09-05
Filing date: 1991-09-05
Publication date: 1993-03-17
Anticipated expiration: 2006-09-05
Also published as: CN1033574C

Abstract

The present invention is a kind of cement, cement expansive material, mixes 10～12% when preparation concrete or mortar, can prepare expansive concrete or mortar, obtains 0.03～0.08% limited expansion rate, improves the anti-crack and anti-seepage ability.

Swelling agent for tuff is by 46～56% the dihydrate gypsum through 600～900 ℃ of incinerating tuffs and 44～54%, the powder that common grinding forms, and grinding fineness is 3～10%.

Description

Swelling agent for tuff

The present invention is a kind of concrete or mortar expansion agent, mix in proportion in concrete or the mortar, but the contraction of compensating concrete improves cracking resistance, impervious ability, improves building performance.

The technology close with the present invention has the manufacture method of cement expansive material, the calcium sulphoaluminate that discloses as " Japan's special permission communique " clear 47-2506 is an expanding material, the constituent of the lime cement expansive material that clear 56-23936 discloses, composite expansive agents for concrete and manufacture method thereof that " Gazette of Patent for Invention " (application number 851009026) discloses, " operating technique " (1987, No.5) U type cement expansive material etc., they all have improves concrete anticracking, impervious effect.On manufacturing process, they all are to need " two mills, burn ", and calcining temperature is 1300～1500 ℃, the manufacturing process complexity, and the alumine that also needs that has is made raw material, so the cost height, and lime and the easy weathering of composite expanding agent, and preservation period is short." expansive concrete " (China Railway Press, nineteen ninety) though the report the alumite plumping agent production technique fairly simple, the alkali (K of this swelling agent ₂O, Na ₂O) content is higher, existing under the situation of reactive aggregate, alkali takes place easily, influences the weather resistance of engineering.

The present invention is directed to the swelling agent the deficiencies in the prior art, develop a kind of swelling agent for tuff.The tuff (or high-alumina clay) that reserves are abundant is through 600～900 ℃ of calcinings, with the calcining tuff (weight ratio) that consists of 46～56%, with 44～54% dihydrate gypsum, common grinding, grinding fineness is the SO that 0.08 mm sieve tails over this swelling agent of 3～10%( ₃Content is 20～29%), promptly can be made into swelling agent for tuff of the present invention.Raw materials used, Al in the calcining tuff ₂O ₃Content is 20～50%, SO in the dihydrate gypsum ₃Content is 34～50%.

The present invention 10～12% mixed (weight ratio) just can prepare expansive concrete or mortar in the Portland cement, improve cracking resistance, antiseepage ability, prolong the work-ing life of buildings.

The calcining of tuff: in brick kiln, put one deck timber earlier, put one deck coal, put a tuffite piece above, put one deck coal again, a tuffite piece, heap from level to level gets on, the igniting calcining.Along with the rising of the intensity of a fire, it is high to continue heap again, and materials such as topped in the above at last one deck clay or powdery iron powder are incubated.Calcining temperature is 600～900 ℃, can use after the cooling.

The present invention is based on ettringite is to produce the expansible root, and ettringite is to rely on the calcining tuff that active A l is provided ₂O ₃, gypsum provides SO ₃The Ca(OH that separates out with hydrated cementitious) ₂Between react to each other and form.At CaO-Al ₂O ₃-SO ₃-H ₂In the O system, as long as there is active A l ₂O ₃, SO ^-2 ₄And Ca(OH) ₂Or CaO just can form ettringite and produce expansion.

The present invention has opened up another active A l ₂O ₃The source, promptly the tuff under 600-900 ℃ of calcining can provide active A l ₂O ₃, have very big meaning.

Compare with the cement expansive material prior art, raw material sources of the present invention are wide, and price is low, only need a grinding on the manufacture method, save the process of general swelling agent raw meal preparation; The present invention only accounts for tuff about half needs calcining, and calcining temperature is than low one times of existing swelling agent, the saving energy consumption, so production technique is simple, cost is low.Alkali content of the present invention is very low, and no alkali-aggregate reaction can guarantee the permanent stability and the weather resistance of engineering.The present invention's easy-weathering not in addition, preservation period is more than 2 years.

Embodiment one:

Raw material Chemical Composition table 1

Title	loss	SiO ₂	Al ₂O ₃	Fe ₂O ₃	CaO	MgO	SO ₃	Crystal water	K ₂O	Na ₂O	Σ
												The calcining tuff	1.35	52.30	32.04	9.79	1.87	0.08	0.12	/	0.44	0.69	98.68
The calcining tuff	2.80	50.75	28.44	9.90	2.55	0.23	/	/	0.43	0.70	95.80
												The calcining tuff	5.09	49.30	27.48	10.29	4.60	0.23	/	/	0.45	0.68	98.12
The calcining tuff	3.80	52.58	26.25	10.25	3.01	0.53	/	/	0.43	0.69	97.52
												The calcining high-alumina clay	6.10	64.35	22.70	1.45	0.65	0.94	/	/	1.00	0.05	97.27
Dihydrate gypsum	19.15	1.94	0.16	0.28	32.71	0.28	45.02	18.88	/	/	99.39
												Dihydrate gypsum	19.0	0.73	0.15	0.08	39.45	1.50	38.95	18.2	/	/	99.86

The composition of swelling agent for tuff and Chemical Composition table 2

Numbering	Form (%)		Fineness 0.08 mm tails over %	Chemical Composition %
														Dihydrate gypsum	The sintering limestone	loss	SiO ₂	Al ₂O ₃	Fe ₂O ₃	CaO	MgO	SO ₃	K ₂O	Na ₂O	Σ
	1	25		75	7.8	5.80	39.72	24.07	7.41	9.58	0.13	11.45	0.33													0.51	99.0
2			46											54	4.7	9.54	29.13	17.37	5.42	16.06	0.17	21.05	0.24	0.37	99.35
	3	50		50	5.0	10.26	27.12	16.10	5.04	17.30	0.18	22.77	0.22													0.34	99.33
4			58											42	4.5	11.68	23.10	13.55	4.27	19.76	0.19	26.39	0.18	0.29	99.41
	5	75		25	8.0	14.70	14.54	8.13	2.66	25.0	0.23	34.10	0.11													0.17	99.64

The physicals of swelling agent for tuff (continuous table 2)

Above-mentioned test: initial set time of coagulation 2: 20～3: 50, final set 3: 05～4: 50.Stability: excellent.

Test shows, tests by the cement expansive material national standard, and the mortar strength of this swelling agent of admixture descend along with increasing of gypsum content in the swelling agent, and swell increment strengthens along with increasing of gypsum content; But the gypsum content of swelling agent 〉=75% o'clock, amount of gypsum increase to expand and reduce on the contrary.

Embodiment two: in order to find out the ratio range of this swelling agent, the basic cement of inquiring into different labels is to its Effect on Performance, and we have done following test again.

The composition of swelling agent for tuff and Chemical Composition table 3

Numbering	Form (%)		Fineness 0.08 mm tails over %	Chemical Composition %
														Dihydrate gypsum	The sintering limestone	loss	SiO ₂	Al ₂O ₃	Fe ₂O ₃	CaO	MgO	SO ₃	K ₂O	Na ₂O	Σ
	7	32		68	6.6	7.05	36.18	21.84	6.76	11.74	0.15	14.61	0.30													0.47	99.1
8			40											60	8.5	8.47	32.16	19.28	5.98	14.20	0.16	18.24	0.26	0.41	99.16
	9	44		56	6.8	9.19	30.14	18.01	5.60	15.44	0.16	20.05	0.25													0.38	99.22
10			46											54	4.7	9.54	29.13	17.37	5.42	16.06	0.17	21.05	0.24	0.37	99.35
	11	50		50	5.0	10.26	27.12	16.10	5.04	17.30	0.18	22.77	0.22													0.34	99.33

The physicals of swelling agent for tuff (continuous table 3)

Above-mentioned test: 2: 20～4: 00 presetting period, final set 3: 00～5: 00, stability: excellent.

Numbering 11-1 is numbering 11 swelling agents of usefulness; Compiling 10-1 is numbering 10 swelling agents of usefulness.

The test of table 2, table 3 shows: 1. the composition of swelling agent for tuff is a calcining tuff 46～56%, dihydrate gypsum 44～54%(weight ratio).Dihydrate gypsum ratio 〉=58%, its strength degradation is more, can not satisfy the requirement of swelling agent national standard to intensity; And if dihydrate gypsum is less than 44%, and then swell increment is too little, can not satisfy the requirement of national standard to swell increment, does not also have the effect of cracking resistance, antiseepage.

2. the grinding fineness of swelling agent be that 0.08mm tails over is 3～10%.

When 3. preparing mortar or concrete, addition content of the present invention is 10～12%, and the limited expansion rate of its 1: 2 mortar is 0.03～0.08%, and 28 days ultimate compression strength of 1: 2.5 mortar is 49～53MPa, reaches the requirement of swelling agent national standard first grade.

4. improve about 5% than its intensity under the free condition under the restricted condition.

5. total SO ₃Content (the SO that swelling agent mixes ₃Mix SO with basic cement ₃Summation) be 4.4～5.9% o'clock, best results.

Example three

Swelling agent for tuff is formed and Chemical Composition table 4

Numbering	Form (%)		Fineness 0.08 mm tails over %	Chemical Composition %
														Dihydrate gypsum	The sintering limestone	loss	SiO ₂	Al ₂O ₃	Fe ₂O ₃	CaO	MgO	SO ₃	K ₂O	Na ₂O	Σ
	12	50		50	6.4	12.31	33.14	11.43	0.86	16.68	0.91	22.51	0.62													0.03	98.49

The physicals of swelling agent for tuff (continuous table 4)

The time of coagulation of above-mentioned test and stability are all qualified.

Test shows, 600～900 ℃ of incinerating high-alumina claies and the common grinding of dihydrate gypsum also can be made swelling agent, and the also available incinerating aluminium of this explanation incinerating tuff clay replaces.

Claims

1, the present invention is a kind of swelling agent for tuff that is used for concrete or mortar, it is characterized in that swelling agent for tuff be by weight ratio 46～56% be that 44～54% the common grinding of dihydrate gypsum to fineness be that 0.08 mm sieve tails over is the powder of 3～10% (weight ratios) through 600～900 ℃ of incinerating tuffs and weight ratio.

2,, it is characterized in that its Al of incinerating tuff as the said swelling agent for tuff of claim 1 ₂O ₃Content is weight ratio 20～50%, and the calcining tuff also can replace with the incinerating high-alumina clay.

3,, it is characterized in that the SO of dihydrate gypsum as the said swelling agent for tuff of claim 1 ₃Content is weight ratio 34～50%, and also available dehydrated gyp-replaces dihydrate gypsum.

4,, it is characterized in that in Portland cement, mixing 10～12%(weight ratio as the said swelling agent for tuff of claim 1) swelling agent for tuff, can prepare expansive concrete or mortar.