阅读说明：本技术 一种磷酸镁水泥修补砂浆及其制备方法 (Magnesium phosphate cement repair mortar and preparation method thereof ) 是由 陈喜旺 张登平 王军 赵文丽 周帅 侯凯 王丽丽 李威 王杰之 范业侃 于 2019-11-16 设计创作，主要内容包括：本发明涉及一种磷酸镁水泥修补砂浆及其制备方法,磷酸镁水泥修补砂浆按重量份包括以下组分：磷酸二氢钾20-35份、氧化镁60-75份、粉煤灰10-20份、细砂10-15份、水12-30份、葡萄糖酸锌1-4份、葡萄糖酸铜1-3份、缓凝剂1-2份、再生混凝土5-10份、硅藻土4-8份以及金属陶瓷微粉3-6份；上述磷酸镁水泥修补砂浆具体包括以下制备步骤：S1.按照重量份进行配料；S2.先对磷酸二氢钾、氧化镁、粉煤灰以及细砂进行低速搅拌；S3.向基料中添加水与缓凝剂继续搅拌,再依次添加再生混凝土废料、葡萄糖酸锌、葡萄糖酸铜、硅藻土以及金属陶瓷微粉进行搅拌,制成浆料；S4.对浆料进行浇筑、振捣、养护处理,使之成型。本发明具有延缓磷酸镁水泥修补砂浆凝结时间的效果。(The invention relates to magnesium phosphate cement repair mortar and a preparation method thereof, wherein the magnesium phosphate cement repair mortar comprises the following components in parts by weight: 20-35 parts of monopotassium phosphate, 60-75 parts of magnesium oxide, 10-20 parts of fly ash, 10-15 parts of fine sand, 12-30 parts of water, 1-4 parts of zinc gluconate, 1-3 parts of copper gluconate, 1-2 parts of a retarder, 5-10 parts of recycled concrete, 4-8 parts of diatomite and 3-6 parts of metal ceramic micro powder; the magnesium phosphate cement repair mortar specifically comprises the following preparation steps: s1, preparing materials according to parts by weight; s2, firstly, stirring the monopotassium phosphate, the magnesium oxide, the fly ash and the fine sand at a low speed; s3, adding water and a retarder into the base material, continuously stirring, sequentially adding the recycled concrete waste, zinc gluconate, copper gluconate, diatomite and the metal ceramic micro powder, and stirring to prepare slurry; and S4, pouring, vibrating and maintaining the slurry to form. The invention has the effect of delaying the setting time of the magnesium phosphate cement repair mortar.)

1. The magnesium phosphate cement repair mortar comprises the following components in parts by weight: 20-35 parts of monopotassium phosphate, 60-75 parts of magnesium oxide, 10-20 parts of fly ash, 10-15 parts of fine sand, 12-30 parts of water, 1-4 parts of zinc gluconate, 1-3 parts of copper gluconate and 1-2 parts of retarder.

2. The magnesium phosphate cement repair mortar of claim 1, wherein: the components also comprise 5-10 parts of recycled concrete.

3. The magnesium phosphate cement repair mortar of claim 1, wherein: the components also comprise 4-8 parts of diatomite.

4. The magnesium phosphate cement repair mortar of claim 1, wherein: the components also comprise 3-6 parts of metal ceramic micro powder.

5. The magnesium phosphate cement repair mortar of claim 4, wherein: the metal ceramic micro powder is preferably oxidation-based metal ceramic micro powder or carbonization-based metal ceramic micro powder.

6. The magnesium phosphate cement repair mortar of claim 1, wherein: the granularity of the potassium dihydrogen phosphate is 30-400 um.

7. The magnesium phosphate cement repair mortar of claim 1, wherein: the retarder is preferably citric acid or lactic acid.

8. The method for preparing magnesium phosphate cement repair mortar according to any one of claims 1 to 7, comprising the following steps:

s1, material preparation: preparing materials according to parts by weight;

s2, mixing base materials: firstly, stirring potassium dihydrogen phosphate, magnesium oxide, fly ash and fine sand at a low speed, wherein the stirring speed is 30-50r/min, and the stirring time is 0.5-1 min;

s3, mixing auxiliary materials: adding water and retarder into the base material, continuously stirring at 30-40 deg.C for 1-3min, sequentially adding recycled concrete waste, zinc gluconate, copper gluconate, diatomaceous earth and metal ceramic micropowder, stirring at 35-45 deg.C for 1-3min, and making into slurry;

s4, forming: and pouring, vibrating and curing the slurry to form the slurry.

Technical Field

The invention relates to the technical field of building materials, in particular to magnesium phosphate cement repair mortar and a preparation method thereof.

Background

At present, Portland cement is mainly used in the world cement industry, the development and application of Portland cement are the most mature, and the Portland cement occupies the dominating position on large-scale engineering projects such as civil engineering, water conservancy and the like, mainly because of stable performance, cheap and easily available raw materials and mature production process. Besides portland cement systems, there are aluminate cement and phosphate cement, among which magnesium phosphate cement is unique in the field of rapid repair due to its early strength and rapid hardening properties.

The magnesium phosphate cement mainly comprises phosphate, magnesium oxide and admixture, and the preparation principle is as follows: MgO is dissolved in phosphate acid solution and ionized to produce Mg ²⁺，Mg ²⁺Form hydrated magnesium ions with water molecules, and further react with phosphate anions to produce hydrated magnesium phosphate gel, H ⁺And O ^2-The reaction produces water, which can release a large amount of heat, so that the saturated gels are mutually cemented and crystallized to form a dense matrix phase with a net structure, and a layer of hydration product film which tightly wraps and connects the surplus magnesium oxide particles into a whole is formed. The hydration product causes the whole system to gradually set and harden. At present, the research on magnesium phosphate cement is still immature, the setting time of the magnesium phosphate cement is short, and the magnesium phosphate cement cannot be suitableThe method is used for large-volume repair engineering.

At present, the Chinese invention with the publication number of CN108249795A discloses magnesium phosphate cement, which comprises the following components in parts by mass: 45-75 parts of magnesium oxide mixture, 15-50 parts of dihydric phosphate and 0-10 parts of retarder; wherein the magnesium oxide mixture comprises calcined dolomite powder, and the preparation method of the calcined dolomite powder comprises the following steps: uniformly mixing the crushed dolomite with the silicon-containing component, calcining at the temperature of 1100-1800 ℃, and grinding the calcined product to obtain the calcined dolomite powder.

The above prior art solutions have the following drawbacks: according to the scheme, through calcining dolomite powder and the silicon-containing component, the silicon-containing component and CaO in a calcined product are combined to form C ₂S, anorthite, diopside and other minerals, and the aim of reducing the activity of CaO in dolomite and delaying the setting time of magnesium phosphate cement is fulfilled, but the production cost is increased by calcination, and the calcination itself consumes time.

Disclosure of Invention

The invention aims to provide magnesium phosphate cement repair mortar which has the effect of delaying the setting time of the magnesium phosphate cement repair mortar.

The second purpose of the invention is to provide a preparation method of the magnesium phosphate cement repair mortar based on the first purpose.

The technical purpose of the invention is realized by the following technical scheme: the magnesium phosphate cement repair mortar comprises the following components in parts by weight: 20-35 parts of monopotassium phosphate, 60-75 parts of magnesium oxide, 10-20 parts of fly ash, 10-15 parts of fine sand, 12-30 parts of water, 1-4 parts of zinc gluconate, 1-3 parts of copper gluconate and 1-2 parts of retarder.

By adopting the technical scheme, zinc gluconate and copper gluconate molecules contain hydroxyl and carboxyl, and the carboxyl is firmly combined with interlayer hydrogen bonds of hydrated magnesium phosphate gel, so that the induction period of crystallization of the hydrated magnesium phosphate gel is prolonged, and the setting time of the magnesium phosphate cement repair mortar is delayed;

the zinc ion and the copper ion are heavy metal ions and are easy to react with PO4 ^3-，HPO4 ^2-The reaction is carried out to generate zinc-containing phosphate with extremely low solubility and copper-containing phosphate precipitate, and the generation of the precipitate delays the speed of crystal dissolution of hydrated magnesium phosphate gel, so that the setting time of the magnesium phosphate cement repair mortar is delayed; the newly formed zinc-containing phosphate and copper-containing phosphate precipitate are wrapped in the network structure of the magnesium phosphate cement repair mortar, and the curing network structure of the magnesium phosphate cement repair mortar tends to be compact and the porosity is reduced along with the extension of the curing time, so that the overall strength of the magnesium phosphate cement repair mortar is improved.

The invention is further configured to: the components also comprise 5-10 parts of recycled concrete.

By adopting the technical scheme, the surface of the recycled concrete is almost coated with the mortar, so that the surface is rough and the specific surface area is large, which is beneficial to improving the adhesion between the recycled concrete and other components, thereby improving the overall adhesion of the mortar; the internal pores of the recycled concrete are large, and other components are filled into the pores, so that the connection strength between the components is improved.

The invention is further configured to: the components also comprise 4-8 parts of diatomite.

By adopting the technical scheme, the diatomite is made of amorphous SiO ₂The diatomite cement repair mortar comprises various organic impurities, is soft, porous and large in viscosity, has good permeability, and is added with diatomite, so that diatomite molecules permeate into base material molecules, and the overall connection strength of the magnesium phosphate cement repair mortar is improved.

The invention is further configured to: the components also comprise 3-6 parts of metal ceramic micro powder.

By adopting the technical scheme, the metal ceramic micro powder has the toughness and the bending resistance of ceramic, and also has the high temperature resistance, the high strength and the oxidation resistance of metal, and the addition of a proper amount of the metal ceramic micro powder in the components is beneficial to improving the physical and chemical properties of the magnesium phosphate cement repair mortar, such as the crack resistance, the oxidation resistance and the like.

The invention is further configured to: the metal ceramic micro powder is preferably oxidation-based metal ceramic micro powder or carbonization-based metal ceramic micro powder.

By adopting the technical scheme, the oxide-based metal ceramic micro powder and the carbide-based metal ceramic micro powder have good high temperature resistance and wear resistance, and the mechanical strength is higher, so that the later strength of the magnesium phosphate cement repair mortar is favorably improved.

The invention is further configured to: the granularity of the potassium dihydrogen phosphate is 30-400 um.

By adopting the technical scheme, the granularity of the monopotassium phosphate has certain influence on the setting time, the compressive strength and the bonding strength of the magnesium phosphate cement repair mortar, so that the granularity of the monopotassium phosphate is controlled within a proper range, and the magnesium phosphate cement repair mortar is favorable for ensuring various physical and chemical properties.

The invention is further configured to: the retarder is preferably citric acid or lactic acid.

By adopting the technical scheme, the citric acid and the lactic acid form a high-stability multi-element annular chelate with free magnesium ions in the magnesium phosphate cement repair mortar, so that the concentration of the magnesium ions in the slurry is reduced, the hydration reaction speed is greatly reduced, and the setting time of the magnesium phosphate cement repair mortar is prolonged.

The second technical purpose of the invention is realized by the following technical scheme: the preparation method of the magnesium phosphate cement repair mortar specifically comprises the following preparation steps:

s1, material preparation: preparing materials according to parts by weight;

s2, mixing base materials: firstly, stirring potassium dihydrogen phosphate, magnesium oxide, fly ash and fine sand at a low speed, wherein the stirring speed is 30-50r/min, and the stirring time is 0.5-1 min;

s3, mixing auxiliary materials: adding water and retarder into the base material, continuously stirring at 30-40 deg.C for 1-3min, sequentially adding recycled concrete waste, zinc gluconate, copper gluconate, diatomaceous earth and metal ceramic micropowder, stirring at 35-45 deg.C for 1-3min, and making into slurry;

s4, forming: and pouring, vibrating and curing the slurry to form the slurry.

By adopting the technical scheme, the base materials are uniformly mixed, water is added into the base materials, the water-cement ratio needs to be controlled within a proper range, and otherwise the physical and chemical properties of the magnesium phosphate cement repair mortar are influenced; and adding auxiliary materials into the base material, uniformly mixing all the components to prepare slurry, and pouring, vibrating and curing the slurry to prepare the mortar.

In conclusion, the beneficial technical effects of the invention are as follows:

1. the addition of zinc gluconate and copper gluconate prolongs the induction period of the crystallization of the hydrated magnesium phosphate gel, so that the setting time of the magnesium phosphate cement repair mortar is delayed; the zinc ions and the copper ions are beneficial to delaying the setting time of the magnesium phosphate cement repair mortar and enhancing the overall strength of the magnesium phosphate cement repair mortar;

2. the addition of the recycled concrete improves the connection strength and the adhesion performance among the components;

3. diatomite molecules penetrate into the base material molecules, so that the overall connection strength of the magnesium phosphate cement repair mortar is improved; 4. the proper amount of the metal ceramic micro powder is added in the components, which is beneficial to improving the physical and chemical properties of the magnesium phosphate cement repair mortar, such as crack resistance, oxidation resistance and the like.

Drawings

FIG. 1 is a flow chart of the production process of this example.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.