Anti-flocculating agent for concrete washed sand and preparation method of anti-flocculating agent

Abstract

The invention discloses a deflocculating agent for concrete washed sand and a preparation method of the deflocculating agent. The deflocculating agent is prepared from 0.5 to 1 part of air entraining agent, 0.1 to 0.2 part of sodium lauryl sulfoacetate, 15 to 30 parts of sodium pyrosulfite, 20 to 32 parts of sodium thiosulfate, 0.5 to 1 part of triethanolamine, 35 to 49 parts of diquat, 2 to 5 parts of maltodextrin, 0.4 to 1 part of cellulose and 0.5 to 1 part of glyceryl monostearate. The anti-flocculating agent provided by the invention can play a role in suspension stabilization, prevents undesirable phenomena of system instability and fluidity reduction caused by particle aggregation, can effectively solve the undesirable problems of high concrete viscosity, insufficient slump retaining performance, easy segregation and bleeding and the like caused by a flocculating agent, effectively reduces the concrete viscosity, and improves the concrete quality. And the construction performance and the quality of hardened concrete are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a deflocculant and a preparation method thereof for solving the problem of residual flocculant in washed sand. Background Art

[0002] The mud, mica, light materials, chloride ions, salts, etc. in sand will have an adverse effect on the quality of concrete, greatly weakening the durability of concrete, thus endangering the life of concrete buildings. In particular, chloride ions and inorganic salts will cause steel bars to rust, greatly endangering the life of buildings. Therefore, concrete sand generally adopts a water washing process in the production process to wash away harmful components in the sand and purify it to meet relevant standards. Due to the limitation of water resources and cost control, coupled with the low efficiency of water washing, flocculants are widely used in sand production, which not only improves the water washing efficiency, but also reduces environmental pressure. The main function of flocculants is to promote the sedimentation and aggregation of suspended matter such as light materials, mud, mica, etc. in the sand during the water washing process, so as to facilitate their separation, thereby achieving the effect of purifying the sand.

[0003] In the existing concrete water-washed sand process, it has become normal for flocculants to remain in concrete sand. Although flocculants can bring positive significance to the quality of concrete sand, the residual flocculants in concrete sand have a great adverse effect on the construction performance of concrete. For example: first, the viscosity of freshly mixed concrete increases, which increases the difficulty of pumping the mixture and brings certain risks of pipe blockage; secondly, under the action of flocculants, cement in the concrete mixture is very easy to separate from aggregates and sink, affecting the collapse resistance and uniformity of the concrete; thirdly, more residual flocculants will cause the mixture to segregate or even bleed, which is not conducive to the construction of concrete and even the quality after hardening; even after being pumped into the mold, the uniformity of the concrete deteriorates, the cement slurry sinks, the aggregate is exposed, and the surface even bleeds, which affects the appearance quality. Flocculant residues bring many disadvantages in terms of concrete setting time, early strength, collapse resistance, and production uniformity control. Especially in Guangdong, more than 80% of the concrete is made of granite, which is more sensitive to collapse agents. Too little flocculant residue will increase the viscosity of the concrete and reduce the fluidity of the concrete; too much residue will cause the concrete to segregate or even bleed, causing great obstacles to concrete construction and ultimately burying major hidden dangers in the performance of the concrete after hardening. Summary of the invention

[0004] In order to solve the shortcomings and deficiencies existing in the above-mentioned prior art, the purpose of the present invention is to provide a deflocculant and a preparation method thereof which can solve the problem of concrete bleeding, effectively improve the control level of the workability of fresh concrete, reduce the occurrence of undesirable phenomena such as insufficient workability and returned materials, and improve the efficiency of concrete construction.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In one aspect, the present invention provides a deflocculant for concrete washed sand, the deflocculant comprising the following components in parts by weight:

[0007]

[0008] Further, the deflocculant comprises the following components in parts by weight;

[0009]

[0010] Furthermore, the air entraining agent includes any one of polyether phosphate, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate.

[0011] Furthermore, the water-retaining agent includes any one of maltodextrin, hydroxypropyl methylcellulose and starch ether.

[0012] On the other hand, the present invention also provides a method for preparing a deflocculant for concrete washed sand, the preparation method comprising the following steps:

[0013] Step 1) weigh the following components by weight: 0.5-1 part of air entraining agent, 0.1-0.2 part of sodium lauryl sulfoacetate, 15-30 parts of sodium pyrosulfite, 20-30 parts of sodium thiosulfate, 0.5-1 part of triethanolamine, 35-49 parts of diutan gum, 2-5 parts of maltodextrin, 0.4-1 part of cellulose, and 0.5-1 part of glyceryl monostearate;

[0014] Step 2) putting the sodium lauryl sulfoacetate, sodium metabisulfite, sodium thiosulfate, triethanolamine, diutan gum, maltodextrin, cellulose, and glyceryl monostearate weighed in step 1) into a blender and mixing to obtain a mixture;

[0015] Step 3) The mixture is stirred evenly by a stirring rod inside the stirrer, and an air entraining agent is added during the stirring process, and the stirring is continued at a stirring speed of 90-120 r / min until it is uniform, and the stirring time is 150-360 minutes to obtain a deflocculant.

[0016] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0017] 1) The deflocculant of the present invention comprises 0.5-1 part of air entraining agent, 0.1-0.2 part of sodium lauryl sulfoacetate, 15-30 parts of sodium pyrosulfite, 20-32 parts of sodium thiosulfate, 0.5-1 part of triethanolamine, 35-49 parts of diutan gum, 2-5 parts of maltodextrin, 0.4-1 part of cellulose, and 0.5-1 part of glyceryl monostearate. The deflocculant of the present invention can play a role in suspension stability, prevent the undesirable phenomenon of system instability and reduced fluidity caused by particle aggregation, and can effectively solve the undesirable problems of high concrete viscosity, insufficient slump retention performance, easy separation and bleeding caused by flocculants, and effectively reduce the viscosity of concrete, ensuring the construction performance and the quality of hardened concrete.

[0018] 2) The preparation method of the present invention can give full play to the efficacy of each component by subjecting each component to reasonable mixing, stirring and other reactions, so that the deflocculant obtained after the preparation of the present invention can reduce the MB value, mud content, chloride ion, salt, mica, soluble matter and other indicators in the sand, thereby solving the technical problem that the residual flocculant in the concrete sand has an adverse effect on the construction performance of the concrete. DETAILED DESCRIPTION

[0019] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention is further described by the following examples. Obviously, the following examples are only part of the embodiments of the present invention, rather than all the embodiments; it should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, rather than to limit the scope of protection of the present invention.

[0020] On the one hand, the present invention provides a deflocculant for concrete washed sand, the deflocculant comprising the following components by weight: 0.5-1 part of air entraining agent, 0.1-0.2 part of sodium lauryl sulfoacetate, 15-30 parts of sodium pyrosulfite, 20-30 parts of sodium thiosulfate, 0.5-1 part of triethanolamine, 35-49 parts of diutan gum, 2-5 parts of maltodextrin, 0.4-1 part of cellulose, and 0.5-1 part of glyceryl monostearate. The deflocculant provided by the present invention can play a good anti-flocculation effect, improve the dispersibility of each component of concrete, improve the uniformity of the mixture, reduce the viscosity of concrete, improve the workability of concrete, and ensure the quality of concrete.

[0021] The air entraining agent added in the present invention can entrain air, increase the fluidity of concrete, and reduce the viscosity of concrete caused by water seepage, and is used in combination with hydroxypropyl methylcellulose ether to improve the fluidity of concrete while ensuring that the air content meets the requirements and does not harm the strength, so that the mixture can resume normal construction.

[0022] In specific implementation, the antiflocculant of the present invention includes the following components by weight: 0.8 parts of air entraining agent, 0.2 parts of sodium lauryl sulfoacetate, 25 parts of sodium pyrosulfite, 25 parts of sodium thiosulfate, 1 part of triethanolamine, 43 parts of diutan gum, 4 parts of maltodextrin, 1 part of cellulose, and 1 part of glyceryl monostearate. The sodium lauryl sulfoacetate in the anti-flocculant of the present invention is an effective foam stabilizer, which plays a role in improving the stability and sustainability of bubbles in the mud system, reducing the viscosity, dispersibility and 2-hour slump retention performance of the cement slurry; the added sodium pyrosulfite plays a role in improving the early strength of the concrete, and alleviates the delayed effect of the flocculant on the setting time and early strength of the cement slurry; the added sodium thiosulfate plays a role in helping to dissolve diutan gum maltodextrin and improving the encapsulation of the concrete; the added triethanolamine plays a role in improving the early strength, delaying the adverse effects of the flocculant on the setting time of the concrete, the insufficient slump retention of the mixture and the like; diutan gum plays a role in dispersing, emulsifying and suspending; the cellulose plays a role in defoaming, thickening and improving the encapsulation of the concrete; and the monostearate glyceryl plays a role in lubrication and emulsification, and improves the workability and pumpability of the concrete.

[0023] In specific implementation, the air entraining agent of the present invention includes any one of polyether phosphate, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate, and the water retaining agent includes any one of maltodextrin, hydroxypropyl methylcellulose, hydroxyethyl cellulose, and starch ether. The sodium dodecyl sulfate added in the present invention can reduce the viscosity and dispersion of cement slurry and improve the slump and expansion of concrete; the added maltodextrin can further improve the anti-precipitation, viscosity and water retention effects of cement slurry.

[0024] Regarding the use principle of the deflocculant of the present invention: the deflocculant of the present invention has strong functionality, but the addition amount is small, and it needs to be mixed into the concrete water reducer for use. The addition amount of different types of concrete water reducers is 3-15kg per cubic meter of concrete; the addition amount of the deflocculant of the present invention is 2%-12% of the amount of the concrete water reducer, which is adjusted according to the residual degree of the flocculant. It is added to the concrete water reducer and fully mixed, and it is uniformly dissolved without precipitation.

[0025] Compared with the current technologies of merely increasing the amount of water reducing agent and water consumption, the anti-flocculant provided by the present invention can not only alleviate the adverse effects of the flocculant on the setting time, but also does not affect the early and late strengths of the concrete, and improves the wrapping of the concrete, reduces the emptying time of the inverted slump cone of the concrete mixture leaving the factory, increases the slump, expansion, 1h slump retention performance of the concrete, etc., and the amount of addition is relatively small, the effect is obvious, the operation is simple, and the anti-flocculant has good practicability.

[0026] On the other hand, the present invention also provides a method for preparing a deflocculant for concrete washed sand, the preparation method comprising the following steps:

[0027] Step 1) weigh the following components by weight: 0.5-1 part of air entraining agent, 0.1-0.2 part of sodium lauryl sulfoacetate, 15-30 parts of sodium pyrosulfite, 20-30 parts of sodium thiosulfate, 0.5-1 part of triethanolamine, 35-49 parts of diutan gum, 2-5 parts of maltodextrin, 0.4-1 part of cellulose, and 0.5-1 part of glyceryl monostearate;

[0028] Step 2) putting the sodium lauryl sulfoacetate, sodium metabisulfite, sodium thiosulfate, triethanolamine, diutan gum, maltodextrin, cellulose, and glyceryl monostearate weighed in step 1) into a blender and mixing to obtain a mixture;

[0029] Step 3) The mixture is stirred evenly by a stirring rod inside the stirrer, and an air entraining agent is added during the stirring process, and the stirring is continued at a stirring speed of 90-120 r / min until it is uniform, and the stirring time is 150-360 minutes to obtain a deflocculant.

[0030] On the other hand, the present invention also provides a method for preparing a deflocculant for concrete washed sand, the preparation method comprising the following steps:

[0031] 1. The present invention is further described below in conjunction with three specific embodiments provided by the present invention:

[0032] In a specific embodiment of the present invention, the deflocculant of the present invention can be configured using the following components (unit: by weight), as shown in the following Table 1:

[0033] Sodium lauryl sulfate, sodium lauryl sulfoacetate, sodium metabisulfite, sodium thiosulfate, triethanolamine, diutan gum, maltodextrin, cellulose, glyceryl monostearate.

[0034] Raw material components Embodiment 1 Embodiment 2 Sodium Lauryl Sulfate 0.8 parts 1 serving Sodium lauryl sulfoacetate 0.2 parts 0.2 parts Sodium metabisulfite 25 servings 25 servings Sodium Thiosulfate 30 servings 30 servings Triethanolamine 1 serving 0.5 serving Diuta 37 servings 39.5 servings Maltodextrin 4 servings 2 servings Cellulose 1 serving 1 serving Glyceryl Monostearate 1 serving 0.5 serving

[0035] Table 1

[0036] According to the weight of each component provided in Example 1 to Example 2 in Table 1 above, a deflocculant is prepared according to the following steps. The preparation method specifically comprises the following steps:

[0037] Step 1) weighing the raw materials of each component of the deflocculant according to the ratios described in Example 1 to Example 2;

[0038] Step 2) putting the sodium lauryl sulfoacetate, sodium metabisulfite, sodium thiosulfate, triethanolamine, diutan gum, maltodextrin, cellulose, and glyceryl monostearate weighed in step 1) into a blender and mixing to obtain a mixture;

[0039] Step 3) The mixture is stirred evenly by a stirring rod inside the stirrer, and an air entraining agent is added during the stirring process, and the stirring is continued at a stirring speed of 90-120 r / min until it is uniform, and the stirring time is 150-360 minutes to obtain a deflocculant.

[0040] 2. The deflocculants prepared in the above embodiments were used in concrete mixtures with residual flocculants, and the properties of the concrete were tested. The test results are as follows:

[0041] (Test 1) Test on the produced pumped C30 concrete mix

[0042] 1. Take the produced pumped C30 concrete mixture. The formula of C30 concrete mixture is shown in Table 1-1 below:

[0043] cement Fly ash water sand gravel Admixtures 270 80 168 855 1040 6.0

[0044] Table 1-1 2. The concrete mixture is tested before leaving the factory, and the performance is shown in Table 1-2 below:

[0045] Table 1-2

[0046] 3. After testing, in the C30 concrete mixture, the residual flocculant in the sand is about 10g / ton of sand, the flocculant type is polyacrylamide, the viscosity of the concrete is relatively large, and there are undesirable conditions such as concrete cement slurry sinking and exposed stones. The antiflocculant prepared in Example 1 is added to the concrete water reducer, and the concrete water reducer with the antiflocculant prepared in Example 1 of the present invention is dissolved in the C30 concrete mixture, stirred evenly for use, and the amount of the antiflocculant is 8% of the amount of the concrete water reducer.

[0047] 4. The performance of the C30 concrete mixture after dissolving the deflocculant was tested. The test results are shown in Table 1-3 below:

[0048]

[0049] Table 1-3

[0050] 5. Test conclusion: It can be seen from Table 1-2 and Table 1-3 that after adding the deflocculant configured in Example 1 of the present invention, the viscosity of the concrete mixture is reduced, especially in terms of flow rate, the improvement is very obvious, and the setting time and strength performance are partially improved.

[0051] (Test 2) Test on the produced pumped C50 concrete mix

[0052] 1. Take the produced pumped C50 concrete mixture. The formula of C50 concrete mixture is shown in Table 2-1 below:

[0053] cement Fly ash water sand gravel Admixtures 360 80 162 760 1060 7.8

[0054] Table 2-1 2. The concrete mixture is tested before leaving the factory, and the performance is shown in Table 2-2 below:

[0055]

[0056] Table 2-2

[0057] 3. After testing, the flocculant residue in the sand of C50 concrete mixture is about 7g / ton sand, and the flocculant type is alum. Factory inspection found that the concrete flow rate is slow, and the collapse time reaches 15.9s, which is very unfavorable for concrete pumping and transportation. If the pumping is high, due to the high viscosity, the pump pressure and pump loss are large, and pipe blockage is very likely to occur. Add the antiflocculant prepared in Example 2 to the concrete water reducer, and add the concrete water reducer dissolved with the antiflocculant prepared in Example 2 of the present invention to the C50 concrete mixture, stir evenly for use, and the amount of antiflocculant in Example 2 is 12% of the amount of concrete water reducer.

[0058] 4. The performance of the C50 concrete mixture after dissolving the deflocculant was tested. The test results are shown in Table 2-3 below:

[0059]

[0060] Table 2-3

[0061] 6. Test conclusion: Combining Table 2-2 and Table 2-3, it can be seen that after adding the deflocculant configured in Example 2 of the present invention to the C50 concrete mixture, the viscosity of the concrete is reduced, the workability and pumpability are significantly improved, and the delay in setting time is alleviated.

[0062] Based on the above embodiments and test results, it can be seen that the use of the deflocculant of embodiments 1 and 2 of the present invention can reduce the viscosity reduction of concrete, can well exert the anti-flocculation effect, improve the dispersibility of the components of concrete, improve the uniformity of the mixture, improve the workability of concrete, and ensure the quality of concrete.

[0063] The implementation methods of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A deflocculant for concrete washed sand, characterized by: The antiflocculant comprises the following components by weight:

2. The deflocculant for concrete washed sand according to claim 1, characterized in that: The antiflocculant comprises the following components by weight:

3. The deflocculant for concrete washed sand according to claim 1, characterized in that: The air entraining agent includes any one of polyether phosphate, sodium dodecyl sulfate and sodium dodecylbenzene sulfonate.

4. The deflocculant for concrete washed sand according to claim 1, characterized in that: The water retaining agent includes any one of maltodextrin, hydroxypropyl methylcellulose and starch ether.

5. A method for preparing a deflocculant for concrete washed sand, characterized in that: The preparation method comprises the following steps: Step 1) weigh the following components by weight: 0.5-1 part of air entraining agent, 0.1-0.2 part of sodium lauryl sulfoacetate, 15-30 parts of sodium pyrosulfite, 20-30 parts of sodium thiosulfate, 0.5-1 part of triethanolamine, 35-49 parts of diutan gum, 2-5 parts of maltodextrin, 0.4-1 part of cellulose, and 0.5-1 part of glyceryl monostearate; Step 2) putting the sodium lauryl sulfoacetate, sodium metabisulfite, sodium thiosulfate, triethanolamine, diutan gum, maltodextrin, cellulose, and glyceryl monostearate weighed in step 1) into a blender and mixing to obtain a mixture; Step 3) The mixture is stirred evenly by a stirring rod inside the stirrer, and an air entraining agent is added during the stirring process, and the stirring is continued at a stirring speed of 90-120 r / min until it is uniform, and the stirring time is 150-360 minutes to obtain a deflocculant.

Images