CN105645825A

CN105645825A - Novel waterproof agent for improving waterproof and impervious performances of concrete

Info

Publication number: CN105645825A
Application number: CN201510995874.XA
Authority: CN
Inventors: 张淑芬
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-12-22
Filing date: 2015-12-22
Publication date: 2016-06-08

Abstract

The invention discloses a novel waterproof agent for improving the waterproof and impervious performances of concrete. The novel waterproof agent is formed by 3wt% of alum, 11wt% of copper sulfate, 30wt% of fly ash, 4wt% of a polycarboxylate superplasticizer, 26wt% of an expanding agent, 0.6wt% of an air entraining agent, 0.4wt% of sodium alkyl sulfonate, 17wt% of silica fume, 2wt% of epoxy resin, 1wt% of 6-dehydroprogesterone, 4wt% of calathea leaf powder and 1wt% of Folium Ginkgo powder; the fly ash is first level fly ash; the expanding agent is an alum stone expanding agent EA-L, a U-shaped concrete expanding agent UEA, a composite expanding agent CEA or a calcium aluminate expanding agent AEA; and the air entraining agent is a non-rosin air entraining agent. The waterproof agent can reduce the amount of porosity, promote cement hydration, improve the density of the concrete, reduce the shrinkage of the concrete and improves the comprehensive durability of the concrete.

Description

The new water repellent of concrete waterproof impervious characteristic can be improved

Technical field

The present invention relates to a kind of new water repellent that can improve concrete waterproof impervious characteristic.

Background technology

Waterproof is the important measures improving cement concrete constructions weather resistance, or even essential measure. The water resistance of cement concrete constructions determines its endurance quality substantially. Cement concrete after hardening, traditional view be it seems, is a kind of compactness material, and in fact, according to currently a large amount of achievements in research, under the service requirements of 50 years even 100 years, portland cement concrete, for water, is not only compactness, and is permeable. Water is the important substance causing cement concrete constructions and reinforced concrete structure durability to damage. It is no matter the soft water erosion of cement concrete, freeze-thaw damage, alkali, steel bar corrosion and sulphate corrosion etc., or the reinforcing bar oxidation corrosion in cement concrete, the corrosion of even water conservancy project, maritime structrue, all it be unable to do without the effect of water, the participation not having water, major part corrodes and almost can not produce. For the cement concrete of water cement ratio at 0.5-0.7, after aquation, its voidage is about 16%. In addition, due to the microfissure that may exist between aggregate and gelling material in cement concrete, moisture can deepen continuously in cement concrete, participates in the corrosion to reinforcing bar in cement concrete or cement concrete. In order to stop the invasion of moisture, it is to increase the water resistant erosion performance of cement concrete constructions and endurance quality, have studied multiple measure, such as the high compactness concrete of Adding Mineral Admixtures, low water binder ratio concrete, surface waterproof paint and concrete bleed etc. Cement concrete is mixed and adds water-resisting agent, form compactness concrete or hate water coagulation soil to reach the object of waterproof, be also a kind of effective technological approaches.

For concrete self, the major cause causing concrete self degradation phenomena is concrete neutralisation (carbonization) and alkali-aggregate reaction. Concrete carbonization is the calcium hydroxide effect in carbonic acid gas and cement stone, generates the process of calcium carbonate and water. Carbonization makes concrete alkalescence reduce, and reduces the provide protection to reinforcing bar, can cause steel bar corrosion. Carbonization also can make concrete carbonization layer produce tensile stress, can cause producing micro-cracks, and concrete tension, folding strength are reduced.

It is alkali-aggregate reaction that concrete raw material produces another reason in crack. Alkali-aggregate reaction is the chemical reaction that the alkali in cement and the reactive aggregate in concrete (active silica) produce. The alkali silicic acid gel that this kind of reaction generates, can produce bigger volumetric expansion, cause distress in concrete, even destroy after water suction. Suppress the measure of alkali-aggregate reaction to have: to select non-reactive aggregate as far as possible, then should strictly control alkali amount total in concrete when not adopting during the aggregate not having activity completely. In addition, mixing active mixed material silicon ash, flyash, has obvious inhibition to alkali-aggregate reaction. Concrete also should be avoided to form surface area water and seam ponding.

In conventional cement, slag cement contract with dry rate is relatively big, and Portland cement takes second place, and pulverized fuel ash cement contract with dry rate is less. In general, construction work and bridge construction adopt Portland cement. Contract with dry rate its splitting resistance little differs and reserves, and to be considered creeping of cement here. As adopted the cement few containing free calcium oxide of regular manufacturer production to prevent bursting apart occurs in concrete. When selection is gathered materials, rubble, coarse sand should be selected, as far as possible without gravel, fine sand, because the former is less than the latter contract with dry rate. With sea sand, the generation of steel bar corrosion dilatation fissure can not be avoided. Pouring large-sized concrete structure can adopt the cement type of the low hydration heat such as slag cement, pulverized fuel ash cement. Mix in order to reduce concrete placing temperature when closing concrete, we can on the rocks or cold water, or sandstone are cooled. Forbid to adopt water or the seawater ready-mixed concrete of containing sulfate or magnesium salt, react with the tricalcium aluminate in cement to avoid, cause volumetric expansion crack or steel bar corrosion dilatation fissure. Do not adopt the admixture containing muriate as far as possible, prevent steel bar corrosion, produce dilatation fissure.

Concrete structure cast, build makings, molding, transport, the other side and assembled and lift process in, if construction technology is unreasonable or construction quality is inferior, will produce to, horizontal and oblique, erect to, level and surface and deeply enter and the various cracks run through, easily occur especially with elongated thin-walled structure. Different owing to producing the reason in crack, therefore, occur that the position in crack, trend and width are not identical yet. As concrete cover is excessively thick, the steel bar stress protective layer bearing hogging moment is thickeied, causes the virtual height of component to reduce, form the crack with steel bar stress vertical direction; Concrete vibrating eakiness, uneven, honeycomb, pitted skin, cavity occur, causes the origin point of steel bar corrosion or other load Cracks; If casting concrete excessive velocities, concrete mobility is lower, heavy real not enough before hardening, heavy real excessive again after hardening, can produce crack after building; The time that concrete stirs and transports is too long, and the evaporation of such moisture is many, thus concrete slump is reduced, and concrete like this volume produces shrinkage crack; When using pumping concrete construction, for ensureing concrete mobility, increasing water and mud consumption, or increase water cement ratio because of other reasons, when causing solidifying soil setting and harden, shrinkage increases so that occur zigzag cracks on volume of concrete; When concrete delamination or segmentation are built, joint area process is not good, easily occurs crack between new-old concrete and construction joint. As concrete delamination build time, rear pouring concrete because of have a power failure, rain etc. reason fail to build before pouring concrete initial set, cause the horizontal slit between aspect;When adopting section cast-in-place, first pouring concrete contact surface dabbing, cleaning not good, between new-old concrete, cohesive force is little, or rear pouring concrete maintenance is not in place, causes concrete shrinkage and causes crack; Concrete early freezc, makes component surface crackle occur, or localized delamination, or occurs hollowing phenomenon etc. after the demoulding.

Concrete admixture be a kind of concrete stir before or mixing process adds, in order to improve the material of concrete performance. Concrete admixture kind is more, and function is different. Use the admixture of various different varieties, different effects can be reached, as improved concrete workability, improve the freezing and thawing performance of maturing, significantly reduce concrete water consumption, improve concrete strength, can compensating concrete drying shrinkage, reduce concrete shrinkage crack, improve concrete erosion resistance, extend concrete work-ing life, it is to increase weather resistance etc. The widespread use of concrete admixture in concrete, has become the 5th group of part essential in concrete, the feature of concrete admixture be kind volume little, newly mix and stir in properties of hardened concrete play an important role in improvement. For ensureing concrete engineering quality, preventing cracking, it is to increase concrete weather resistance, concrete admixture refers to and mixes in mixing concrete process, in order to improving the material of concrete performance. Adopt suitable admixture, concrete water consumption can be reduced, increase concrete mobility and workability etc. But the volume of admixture should not be greater than the 5% of cement quality, though its volume is little but its effect is very obvious. As mixed water reducer, ensureing can reduce cement consumption to greatest extent under the prerequisite that concrete meets design strength. Mix retardation water reducing agent and can extend the concrete presetting period, postpone hydration heat speed and the time of thermal peak appearance, the early stage internal-external temperature difference of concrete will be reduced like this, be conducive to the appearance of crackle preventing. Adding swelling agent can make concrete obtain certain expansion value, to offset or to slow down the tensile stress produced due to concrete shrinkage, thus prevents concrete from producing cracking. Admixture conventional in mass concrete has lignin sulfonate water reducer, efficient retardation water reducing agent, UEA type swelling agent etc.

Concrete, under suitable curing condition, should be waterproof after hardening, but in fact, normal concrete always has infiltration to a certain degree or leaks usually, and this can occur in the place of construction joint, it is also possible to occurs on concrete body. Learnt by a large amount of experimental and theoretical analysis, cause the major cause (except construction reason) of concrete seepage water to have: 1. inside concrete exists thick kapillary a fairly large number of, connection property, and capillary wall is hydrophilic; 2. the various contractions that concrete produces in process of setting cause concrete cracking, and in many cases, cracking is the main reason causing concrete seepage water. Therefore, to fundamentally solve self-waterproof concrete leakage problems. just must accomplish: 1. subtract step capillary tube quantity, cut off the kapillary being connected. refinement capillary aperture. make kapillary ancient piece of jade, round, flat and with a hole in its centre hydrophobisation; 2. reduce or avoid concrete to produce volumetric shrinkage, eliminate crackle. The feature of concrete water-proof technology can take the different practices according to different engineerings, structure, and construction is simple, convenient. cost is lower. it is easy to maintenance, waterproof good endurance. So, in civil construction project, concrete water-proof occupies critical role. but due to the feature of Portland cement self and the intrinsic defect of concrete inner structure, it is desired to design is careful, and construction is strict, can prove effective.In order to overcome the existing defect of concrete itself, it is all by mixing various water-resisting agent in normal concrete both at home and abroad. Solve a series of problems of concrete water-proof technology preferably. At present, on China construction market sell mainly inorganic or organic water-resisting agent. such as iron(ic) chloride, aluminum chloride. trolamine, the water-resisting agents such as organosilicon. By adding these water-resisting agents, form lame body or complex compound, blocking pore, it is to increase concrete impervious ability; Another kind of method mixes air entrapment agent, forms the micro-bubble not being connected, cuts off capillary porosity duct; The third method adds water-resisting agent, reduces water cement ratio. Reduce porosity, refinement capillary aperture; 4th kind of method mixes swelling agent, is mixed with expansive concrete, to improve concrete crack resistance. Facts have proved, most of water-resisting agent to improve the solidifying native impervious ability of rod, but, first three methods is in actual application. often there is the phenomenon that concrete shrinkage ftractures and cause seepage. Although the 4th kind of method can avoid concrete shrinkage cracking problem, but, owing to common swelling agent expects that volume is very big. Concrete water requirement increases more. The requirement of construction technology and maintenance is very strict, otherwise be easy to produce plastic shrinkage crackle. Cause the failure of waterproof.

Summary of the invention

In view of this, technical problem to be solved by this invention is: provide a kind of new water repellent that can improve concrete waterproof impervious characteristic.

In order to achieve the above object, the present invention adopts following technical scheme to realize:

A new water repellent for concrete waterproof impervious characteristic can be improved, wherein, it is made up of the component of following weight percent:

Alum 3%; Copper sulfate 11%; Flyash 30%; Polycarboxylate water-reducer 4%; Swelling agent 26%; Air entrapment agent 0.6%; Alkyl sodium sulfonate 0.4%; Silicon ash 17%; Epoxy resin 2%; 6-removes hydrogen Progesterone 1%; White line arrowroot leaf powder 4%; Ginkgo Leaf powder 1%; Described flyash is first level flour coal ash; Described swelling agent is alumite plumping agent EA-L, U-shaped cement expansive material UEA, composite expanding agent CEA or bulking agent of calcium aluminate AEA; Described air entrapment agent is non-rosin based air entrapment agent.

Preferably, described flyash is first level flour coal ash, and described first level flour coal ash was the flyash of the amount of tailing over��12% after 45 ��m of square hole sieves; Wherein, alum: i.e. Potassium aluminum sulfate dodecahydrate, by alunite through calcining, extraction, crystallization and obtain. Chemical formula is KAl (SO4) 2 12H2O, and water white transparency, in cube octahedral crystallization or monocline cube crystallization, plays cohesion.

Copper sulfate: molecular formula is CuSO4 is the asymmetric triclinic(crystalline)system crystallization of sapphirine or powder.

Polycarboxylate water-reducer: high-performance water reducing agent, polyester type or polyether-type structure, it is possible to effectively reduce concrete cement consumption, it is also possible to significantly reduce concrete shrinkage.

Swelling agent: the expansive clinker being made up of different minerals grinds with powder such as gypsum, can adopt alumite plumping agent EA-L, U-shaped cement expansive material UEA, composite expanding agent CEA and bulking agent of calcium aluminate AEA etc.

Air entrapment agent: adopt non-rosin based air entrapment agent, can improve concrete workability, that reduces compound secretes water, improves concrete impervious and anti-freezing property and contributes to transport and build.

Alkyl sodium sulfonate: be the one in air entrapment agent, can effectively reduce the harm of alkali-aggregate reaction in concrete, improve concrete workability, and the segregation reducing mixture secretes water, it is to increase concrete weather resistance and frost resistance, but can reduce concrete intensity when it is singly mixed.

Silicon ash: main component SiO2, grey or pale powder, the hole between energy filling concrete particle, generates gelinite with hydrated product simultaneously, generates gelinite with the reaction of basic material magnesium oxide.Effects such as there is Bao Shui, prevent segregation, secrete water.

As shown from the above technical solution, the invention has the beneficial effects as follows:

Water-resisting agent of the present invention can avoid other water resisting admixture waterproof and control distress in concrete not phenomenon thoroughly, it is possible to improves concrete structure and overcomes concrete self-defect, thus reaches comprehensive system waterproof and the object of control distress in concrete. This water-resisting agent has the concrete water permeability making maintenance good and reduces so that maturing has the function of waterproof or hydrophobic nature. The mechanism of action of this water-resisting agent is divided into active and non-activity, what is called have activity refer to water-resisting agent can with some composition generation chemical reaction in cement, resultant of reaction can make cement stone volume more closely knit, thus improve concrete impermeability, prevent calcium hydroxide and meet water precipitation, reach the object of waterproof. But not activity refers to that any chemical reaction does not occur water-resisting agent itself with cement, their effect is inertia fillibility, makes concrete compaction, thus reaches the effect of waterproof. In addition, add water reducer, air entrapment agent component, due to their dispersion and air-entraining effect, the water cement ratio of concrete or mortar can be reduced to a certain extent; Aperture and the pore distribution of kapillary can be changed, aperture is diminished; The surface tension of liquid one gas phase can also be reduced, make cement granules better wetting. These all can make the absorption of kapillary strengthen, and adds the resistance of moisture by kapillary, thus reduces infiltration, it is to increase water-repellancy. In addition, it may also be useful to some hydrophobic substance can also improve concrete impermeability. The present invention by adding epoxy resin, 6-remove hydrogen Progesterone, white line arrowroot leaf powder and Ginkgo Leaf powder, significantly improve concrete waterproof impervious characteristic.

Existing water-resisting agent mostly is inorganic or organic water-resisting agent, such as water-resisting agents such as iron(ic) chloride, aluminum chloride, organosilicons. relative to water-resisting agent of the prior art, the new water repellent that the present invention can improve concrete waterproof impervious characteristic is mixed with alum, flyash, polycarboxylate water-reducer, alkyl sodium sulfonate etc., by water reducer, swelling agent, air entrapment agent, epoxy resin, 6-removes hydrogen Progesterone, white line arrowroot leaf powder and Ginkgo Leaf powder etc. have carried out building preparation, it is made to play respective advantage and overcome its defect separately, avoid other water resisting admixture waterproof and control distress in concrete not phenomenon thoroughly, and improve concrete structure and overcome concrete self-defect, thus reach comprehensive system waterproof and the object of control distress in concrete better. water-resisting agent of the present invention can reduce porosity, promotes hydrated cementitious, improve concrete density, can reduce again concrete contraction, and can also improve concrete Synthesis durability energy.

Embodiment

In order to make those skilled in the art can further understand feature and the technology contents of the present invention, refer to following detailed explanation for the present invention.

Embodiment 1

Alum 3kg; Copper sulfate 11kg; Flyash 30kg; Polycarboxylate water-reducer 4kg; Swelling agent: alumite plumping agent EA-L26kg; Air entrapment agent: acrylic acid epoxy fat 0.6kg; Alkyl sodium sulfonate 0.4kg; Silicon ash 17kg; Epoxy resin 2kg; 6-removes hydrogen Progesterone 1kg; White line arrowroot leaf powder 4kg; Ginkgo Leaf powder 1kg, described flyash is first level flour coal ash.

Embodiment 2

To improving the performance test of new water repellent of concrete waterproof impervious characteristic described in embodiment 1 and be analyzed as follows:

Mix the concrete having added this water-resisting agent and not only there is high impervious, impermeable structure, but also require that there is crack autogenous healing performance, namely when microfracture occurs in inside concrete, special composition in water-resisting agent is blocked as silicon ash and alum etc. can impel unhydrated cement in concrete to produce new crystal crack under certain condition, thus gives concrete permanent water resistance.

(1) high performance water proof agent is on the impact of concrete impermeability

The concrete important indicator mixing water-resisting agent is anti-permeability performance, and the index evaluating concrete anti-permeability performance at present mainly contains permeated height ratio, impermeability pressure. Water-resisting agent volume is on the impact of concrete impervious pressure. Test is it may be seen that along with the increase of water-resisting agent volume, the concrete permeated height mixing water-resisting agent, than significantly reducing, shows that concrete waterproof impervious characteristic significantly improves. When Anti-leakage instrument pressure is added to 0.6MPa, normal concrete is all permeable, and permeated height ratio is 100%. The concrete mixing water-resisting agent is also added to this pressure, and keeps the identical time, and when water-resisting agent volume is 3%, permeated height ratio is 33%, illustrates that water-resisting agent can significantly improve concrete water-proof anti-permeability performance. When water-resisting agent volume brings up to 5% further, permeated height ratio continues to drop to 23%, meets in JC474-2008 permeated height than the requirement being less than 30%. Volume is increased to 6%, and permeated height ratio is 10%, and now concrete has good waterproof impervious characteristic, then increases volume, and permeated height slows down than reduction trend, shows that water-resisting agent moderate dosage is 6%. And ferric chloride waterproofing agent volume is generally advisable with 3%. Its content crosses multipair steel bar corrosion, concrete thousand contracts, time of coagulation have impact, lacked effect remarkable not. Water-resisting agent volume is on the impact of concrete 14d impermeability pressure and 28d secondary resistance to permeability pty, it can be seen that normal concrete does not possess crack autogenous healing performance. After mixing the water-resisting agent of 3%, concrete 14d impermeability pressure reaches 1.6MPa, and 28d secondary resistance to permeability pty is 1.96MPa, shows that water-resisting agent can make the penetrating passage in concrete be repaired. When water-resisting agent volume is 5%, concrete 14d impermeability pressure reaches 2.8MPa, and 28d secondary resistance to permeability pty is 2.95MPa, and the concrete mixing 6% water-resisting agent is described, and in 14d, seepage-resistant grade can close to P30.

The present invention by adding epoxy resin, 6-remove hydrogen Progesterone, white line arrowroot leaf powder and Ginkgo Leaf powder, significantly improve concrete waterproof impervious characteristic, attempt when testing eliminating this three kinds of components, then concrete waterproof impervious characteristic obviously weakens. Testing data is respectively: when Anti-leakage instrument pressure is added to 0.6MPa, normal concrete is all permeable, and permeated height ratio is 100%. Mix and do not go the concrete of water-resisting agent of hydrogen Progesterone and white line arrowroot leaf powder to be also added to this pressure containing epoxy resin, 6-, and keep the identical time, when water-resisting agent volume is 3%, permeated height ratio is 48%, illustrates that water-resisting agent can significantly improve concrete water-proof anti-permeability performance. When water-resisting agent volume brings up to 5% further, permeated height ratio continues to drop to 36%, and it differs a lot of with effect when adding this three kinds of components.

(2) water-resisting agent is on the impact of concrete crushing strength ratio

Mixing after having added water-resisting agent, for keeping concrete slump in certain limit, concrete water-cement ratio lowers gradually, and water-resisting agent has and necessarily subtracts water function. When water-resisting agent volume is 6%, water-reducing rate is about 16%, and for waterproofing agent of organosilicon, when its volume is 1%, water-reducing rate is about 20%, and also increases with volume increase water-reducing rate. This illustrates that this water-resisting agent is not that the mode mainly through reducing water cement ratio is to improve anti-permeability performance.

The new water repellent that can improve concrete waterproof impervious characteristic joins in concrete, it is carry out air free concrete structure by active admixture component on the one hand, concrete strength development is accelerated by organic and inorganic enhancement component, it is the cement aquation again being promoted incomplete aquation in concrete by active catalytic components on the other hand, improves concrete structure density and intensity further.

But the foregoing is only the better possible embodiments of the present invention, it does not mean to the patent scope of limitation the present invention, therefore the equivalent structure change that all utilizations description of the present invention is done, all with reason within the scope of the present invention.

Claims

1. one kind can be improved the new water repellent of concrete waterproof impervious characteristic, it is characterised in that, it is made up of the component of following weight percent: