CN102276176A - High-performance Portland cement for dam - Google Patents

Abstract

The invention provides a high-performance Portland cement for a dam, aiming at solving the problem that an admixture is not used in moderate-heat Portland cement and low-heat Portland cement but clinker is used completely, therefore the environment friendliness is not facilitated and the cost of cement is also increased. The high-performance Portland cement disclosed by the invention is characterized by being formed by homogenizing ground general Portland cement clinker and the admixture, wherein the admixture accounts for 30% to 75% of total weight of the cement. The invention has the advantages that: the performance of the cement is obviously enhanced after the addition quantity of the admixture is increased; especially, the hydration heat effect is obviously reduced; after the addition quantity of the admixture is increased, the proportion of the clinker in the cement is reduced; the environment friendliness is facilitated, and the cost is also reduced; and simultaneously, the effective and cyclic utilization of industrial waste residues is also realized.

Description

High-performance dam silicate cement

Technical field

The present invention relates to a kind of cement, is a kind of hydro project and tunnel, culvert specifically, the cement that uses in the prevention of mass concrete engineerings such as bridge.

Background technology

At present China in the ocean, hydro project such as rivers, reservoir and tunnel, culvert, the cement that uses in the prevention of mass concrete engineerings such as bridge is according to GB200-2003 standard production moderate-heat portland cement, low-heat portland cement and low heat portland blast-furnace-slag cement.The blending amount of mixture material of this standard centering heat and low-heat portland cement is stipulated; i.e. admixture blended material not; regulation low heat portland blast-furnace-slag cement allows to mix 20% ~ 60% granulated blast-furnace slag, and (per-cent is meant that this material accounts for the per-cent of whole cement weight; together following), and allow to come the instead of part granulated blast-furnace slag with the granulation electric furnace phosphoric slag or the flyash that are no more than blended material total amount 50%.The component of heat and low-heat portland cement mainly is a grog in above-mentioned, and a spot of gypsum; The component of low heat portland blast-furnace-slag cement is: except that grog and a spot of gypsum, and no more than 60% the blended material of having gone back admixture.As seen do not use blended material in heat and the low-heat portland cement in, its main raw material all uses grog.This both had been unfavorable for environmental protection, had also increased the cost of cement.

Summary of the invention

For reducing the usage quantity of grog, reduce cost, help environmental protection, the object of the present invention is to provide a kind of admixture to be not more than 75% blended material, all the other are the general purpose portland cement grog, reduce hydration heat, particularly suitable in hydro project and tunnel, culvert, the high-performance dam silicate cement that uses in the prevention of mass concrete engineerings such as bridge.

The object of the present invention is achieved like this: its main raw material is grog and the blended material behind the grinding, and wherein blended material accounts for the 30-75% of cement gross weight.

Said grog, before grinding, tricalcium aluminate≤8%, free calcium oxide≤1.5%, alkali content≤0.8%, 3d ultimate compression strength 〉=25.0MPa28d, ultimate compression strength 〉=52.5MPa, its specific surface area 400-500 ㎡/kg behind the grinding; 80 μ m square hole sieves tail over to be not more than and omit square hole sieve below the 2.0%(), 45 μ m tail over and are not more than 5.0%;

Said each composition of main blended material and requirement thereof are:

(1) flyash reach the II level or more than, loss on ignition≤7.5% wherein, 28d ultimate compression strength activity index 〉=75%, specific surface area behind grinding 〉=750 m ²/ kg;

(2) granulated blast-furnace slag quality coefficient 〉=1.3, wherein titanium dioxide (TiO ₂)≤10.0%, manganese monoxide (MnO)≤4.0%, 28d ultimate compression strength activity index 〉=105% requires slag powders specific surface area 〉=460 m behind grinding ²/ kg, 80 μ m tail over≤and 2.0%, 45 μ m tails over≤and 5.0%;

The fineness index of above each component can guarantee that high-performance dam silicate cement of the present invention has good microcosmic continuous grading, each levigate material can be filled the space mutually, thereby significantly improved the mechanical property of cement, also improved concrete compactness and weather resistance.

Compared with prior art, the invention has the beneficial effects as follows: not only the performance of cement did not reduce after blending amount of mixture material strengthened, and was significantly improved on the contrary, and it is remarkable particularly to reduce the hydration heat effect, makes it to be applied to can effectively control cracking in the concrete.Owing in cement, improved the addition content of blended material, reduced the ratio (promptly reduced usage quantity and the output of grog) of grog in cement, not only help environmental protection, save energy, also realized effective utilization of industrial residue simultaneously, recycling economy has been saved the Cement Production cost greatly.

Embodiment

Specify the present invention below in conjunction with examples of implementation.

The present invention is divided into 32.5 grades by the strength of cement grade, and 42.5 grades, 52.5 grades.Below provide the specific embodiments and the performance index thereof of this Three Estate.

One, the cement formula of Three Estate (%) is respectively:

Grade	Grog	Flyash	Breeze+desulfurated plaster	The plaster of paris	Grinding aid
						32.5 level	26.4	16.0	54.1	3.0	0.5
42.5 level	35.0	11.5	50.0	3.0	0.5
						52.5 level	44.0	7.5	45.0	3.0	0.5

Wherein each quality requirements of raw materials is:

1, general purpose portland cement grog

2, flyash require to reach the II level or more than, loss on ignition≤7.5% wherein, 28d ultimate compression strength activity index 〉=75%, specific surface area behind grinding 〉=750 m ²/ kg;

3, granulated blast-furnace slag quality coefficient 〉=1.3, wherein titanium dioxide (TiO ₂)≤10.0%, manganese monoxide (MnO)≤4.0%, 28d ultimate compression strength activity index 〉=105% requires slag powders specific surface area 〉=460 m behind grinding ²/ kg, 80 μ m tail over≤and 2.0%, 45 μ m tails over≤and 5.0%.

Two, being mixed with the every quality parameter of high-performance dam silicate cement through homogenizer is:

1, intensity

2, time of coagulation

Grade	Presetting period h:min	Final setting time h:min
			32.5 level	3:15	4:35
42.5 level	3:00	4:00
			52.5 level	3:00	4:15

3, the stability boiling process is qualified

4, fineness

Grade	Specific surface area m 2/kg	80 μ m tail over %	45 μ m tail over %
				32.5 level	413	0.4	1.0
42.5 level	476	0.3	2.0
				52.5 level	508	The all-pass mistake	0.2

5, particle grading distribution

Size distribution	3-24μm	3-32μm	Below the 32 μ m
				32.5 level	58.55	68.31	88.31
42.5 level	60.87	68.69	92.34
				52.5 level	63.61	67.81	98.24

6, grain roundness coefficient

Grade	32.5 level	42.5 level	52.5 level
				The circularity coefficient	0.76	0.78	0.81

7, chemical analysis results

Grade	Sulphur trioxide	Loss on ignition	Magnesium oxide	Chlorion	Alkali content
						32.5 level	3.08	2.51	4.90	0.028	0.58
42.5 level	2.97	2.64	4.77	0.024	0.58
						52.5 level	2.69	2.92	4.59	0.035	0.59

8, hydration heat

Grade	3d	7d
			32.5 level	191	218
42.5 level	223	249
			52.5 level	244	279

Making method is: with grog and blended material difference grinding, utilize homogenizer that two kinds of powders are prepared, stirred according to the proportioning of above-mentioned three strength grades then, make the cement of Three Estate.

Claims (2)

1. high-performance dam silicate cement, its main raw material is that general purpose portland cement grog and the blended material behind the grinding constitutes after homogenizing, wherein blended material accounts for the 30-75% of cement gross weight;

Said grog, before grinding, tricalcium aluminate≤8%, free calcium oxide≤1.5%, alkali content≤0.8%, 3d ultimate compression strength 〉=25.0Mpa, 28d ultimate compression strength 〉=52.5MPa, its specific surface area 400-500 ㎡/kg behind the grinding; 80 μ m tail over and are not more than 2.0%, 45 μ m and tail over and be not more than 5.0%;

Each composition of said blended material and requirement thereof are:

(1) flyash reach the II level or more than, loss on ignition≤7.5% wherein, 28d ultimate compression strength activity index 〉=75%, specific surface area behind grinding 〉=750 m ²/ kg;

(2) granulated blast-furnace slag quality coefficient 〉=1.3, titanium dioxide≤10.0% wherein, manganese monoxide≤4.0%, 28d ultimate compression strength activity index 〉=105%, slag powders specific surface area behind grinding 〉=460 m ²/ kg, 80 μ m tail over≤and 2.0%, 45 μ m tails over≤and 5.0%.

2. according to the described high-performance dam of claim 1 silicate cement, it is characterized in that:

The cement formula of three strength grades is respectively:

Grade Grog Flyash Breeze+desulfurated plaster The plaster of paris Grinding aid 32.5 level 26.4 16.0 54.1 3.0 0.5 42.5 level 35.0 11.5 50.0 3.0 0.5 52.5 level 44.0 7.5 45.0 3.0 0.5

Wherein the requirement of general purpose portland cement grog is:

。