Inorganic composite mortar, preparation method and application thereof
Patent Information
- Application Number
- CN202610869432.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-16
- Publication Date
- 2026-09-15
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of building waterproofing materials technology, and in particular to an inorganic composite mortar, its preparation method and its application. Background Technology
[0002] When building water supply, drainage, HVAC, and other pipes penetrate floors and walls, the junction between their roots and the concrete substrate and the outer wall of the pipe is the weakest point for leakage in waterproofing projects. Current technology mainly uses ordinary cement mortar or fine aggregate concrete for on-site sealing, but these materials have the following technical defects in practical applications: slow setting and hardening, low early strength. The initial setting time of ordinary silicate cement-based materials is usually more than two hours. After construction, they are easily affected by subsequent processes or micro-vibrations in the pipes, leading to displacement and loosening of the sealing layer, resulting in sealing failure; severe shrinkage cracking. Cement-based materials exhibit significant drying shrinkage and chemical shrinkage during the hardening process, with a volume shrinkage rate of 0.04%-0.08%. This easily forms shrinkage cracks at the interface between the mortar and the smooth outer wall of PVC, galvanized steel pipes, and the concrete substrate, becoming seepage channels; poor compactness and low impermeability. Traditional mortar has high internal capillary porosity, and its impermeability pressure is usually less than P6. Long-term exposure to damp environments such as kitchens, bathrooms, and basements can easily lead to dampness and leakage.
[0003] Furthermore, while some organically modified sealing materials offer some waterproofing, their poor aging resistance and potential presence of volatile organic compounds make them unsuitable for enclosed indoor spaces. These issues have led to pipe root leakage becoming a common quality problem in the building waterproofing industry, necessitating a specialized sealing mortar that combines rapid hardening and early strength, micro-expansion and crack resistance, high impermeability, strong adhesion, and environmental friendliness. Summary of the Invention
[0004] This invention addresses the shortcomings of existing technologies by providing an inorganic composite mortar, its preparation method, and its application. By constructing a dual-cementing system of rapid-hardening sulfoaluminate cement and hemihydrate desulfurized gypsum, and by coordinating inorganic expanding agents and organosilicon water-repellent agents, the mortar achieves rapid hardening and early strength, micro-expansion and crack resistance, and high impermeability. This ensures that the mortar does not shrink, leak, or fall off after sealing the pipe root, meeting the dual requirements of rapid construction and long-term waterproofing.
[0005] Therefore, the first objective of this invention is to provide an inorganic composite mortar.
[0006] The second objective of this invention is to provide a method for preparing inorganic composite mortar.
[0007] The third objective of this invention is to provide an application of inorganic composite mortar.
[0008] To achieve the first objective of this invention, the technical solution of this invention provides an inorganic composite mortar, comprising, by weight: 30-40 parts of rapid-hardening sulfoaluminate cement; 8-12 parts of hemihydrate desulfurized gypsum; 30-35 parts of refined quartz sand; 2-8 parts of activated silica fume; 0.2-0.6 parts of organosilicon water-repellent agent; 0.2-0.8 parts of calcium oxide inorganic expanding agent; 0.1-0.2 parts of polypropylene fiber; 0.2-0.3 parts of polycarboxylate superplasticizer; 0.06-0.1 parts of hydroxypropyl starch ether; and 15-30 parts of water.
[0009] Compared with existing technologies, the technical effects achieved by this solution are as follows: Rapid-hardening sulfoaluminate cement, as the main cementitious component, has a fast hydration rate and high early strength, providing rapid setting capability for the mortar. Hemihydrate desulfurized gypsum, as an auxiliary cementitious component, regulates setting time and provides sulfate ions to react with calcium aluminate in the sulfoaluminate cement to generate more stable ettringite, forming a dense crystal framework, further optimizing the pore structure and improving early strength. The combination of these two components constitutes a dual cementitious system; a ratio of 30-40 parts cement to 8-12 parts gypsum achieves an optimal balance between setting time and strength development. Refined quartz sand, as aggregate, at a dosage of 30-35 parts, ensures the volume stability and workability of the mortar. Active silica fume, with its high pozzolanic activity and ultrafine particle size, at a dosage of 2-8 parts, effectively fills the capillary pores between cement particles, significantly improving the mortar density. Organosilicon hydrophobic agents hydrolyze and condense in an alkaline environment; a dosage of 0.2 to 0.6 parts can form a chemically bonded hydrophobic network on the pore wall surface, giving the mortar overall hydrophobic properties. Calcium oxide-based inorganic expanding agents hydrate to form calcium hydroxide, causing volume expansion; a dosage of 0.2 to 0.8 parts can compensate for shrinkage during the mortar hardening process and eliminate interfacial gaps. Polypropylene fibers are distributed in a three-dimensional random pattern in the mortar; a dosage of 0.1 to 0.2 parts can effectively prevent the propagation of microcracks. Polycarboxylate superplasticizers provide good fluidity at low water-cement ratios, while hydroxypropyl starch ethers thicken and retain water to prevent sagging; the two work synergistically to ensure workability. These characteristics together endow the mortar with comprehensive properties such as rapid hardening and early strength, micro-expansion and crack resistance, high impermeability, and strong adhesion, providing a solution for waterproofing and sealing pipe roots.
[0010] In one technical solution of the present invention, the fineness of the active silica fume is ≥900 mesh.
[0011] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the active silica fume with a fineness of ≥900 mesh has a higher specific surface area and pozzolanic activity, which can more fully fill the micron and submicron pores between cement particles, significantly reduce the capillary water absorption coefficient of mortar, and thus further improve the impermeability grade.
[0012] In one embodiment of the present invention, the length of the polypropylene fiber is 2mm-4mm.
[0013] Compared with existing technologies, the technical effects achieved by this solution are as follows: Fiber lengths of 2mm to 4mm exhibit optimal dispersion in mortar, forming an effective three-dimensional reinforcement network without causing agglomeration or affecting troweling due to excessive fiber length. Fibers within this length range work synergistically with the inorganic expanding agent; the expanding agent provides compressive stress to compensate for shrinkage, while the fibers provide tensile stress to prevent the propagation of microcracks. Together, they prevent the formation of shrinkage cracks.
[0014] In one technical solution of the present invention, the refined quartz sand has a mesh size of 40-70 mesh.
[0015] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the 40-70 mesh quartz sand has a reasonable gradation, which not only ensures the skeleton strength of the mortar, but also avoids the difficulty of troweling caused by excessively coarse sand particles or the shrinkage increase caused by excessively fine sand particles. At the same time, this particle size range forms a good gradation filling effect with the active silica fume, further optimizing the pore structure of the mortar.
[0016] In one technical solution of the present invention, the initial setting time of the inorganic composite mortar is 30min-40min, the final setting time of the inorganic composite mortar is 60min-80min, the 24h compressive strength of the inorganic composite mortar is ≥20MPa, and the impermeability grade of the inorganic composite mortar is ≥P10.
[0017] Compared with existing technologies, the technical effects achieved by this solution are as follows: Through the synergistic effect of the above components and proportions, the inorganic composite mortar of this invention has the ability to quickly set; it can resist slight disturbances after initial setting in 30-40 minutes, and has a certain strength after final setting in 60-80 minutes; its 24-hour compressive strength reaches over 20 MPa, meeting the requirements for early intervention in subsequent waterproofing processes; and its impermeability grade reaches P10 or higher, ensuring no leakage during long-term use. These performance parameters are key technical indicators for achieving rapid and long-lasting waterproofing and sealing of pipe roots.
[0018] To achieve the second objective of this invention, the technical solution of this invention provides a method for preparing inorganic composite mortar as described in any of the above technical solutions, comprising the following steps: S100, dry material mixing: adding rapid-hardening sulfoaluminate cement, hemihydrate desulfurized gypsum, active silica fume, and calcium oxide inorganic expanding agent to a mixer according to mass parts, and mixing to obtain a first mixture; S200, compound mixing: adding refined quartz sand, polypropylene fiber, polycarboxylate superplasticizer, and hydroxypropyl starch ether to the first mixture, and continuing to mix to obtain a second mixture; S300, on-site mixing: mixing the second mixture with water and organosilicon water-repellent agent until it becomes a paste to obtain inorganic composite mortar.
[0019] Compared with existing technologies, the technical advantages of this solution are as follows: First, the dry mixing step mixes the cementitious components with the active admixtures in advance, ensuring the uniform dispersion of fine powder components such as cement, gypsum, silica fume, and expanding agent, and preventing later agglomeration. Second, the compound mixing step adds aggregates and fibers, utilizing the already uniformly mixed fine powders to drive the dispersion of quartz sand and fibers, improving overall mixing efficiency. Finally, the on-site mixing step adds water and organosilicon water-repellent agent simultaneously. The organosilicon water-repellent agent can better emulsify, disperse, and undergo hydrolysis and condensation reactions in an alkaline environment. The entire method is simple, easy to operate, and the dry-mixed powder can be pre-produced and sealed in packaging. On-site, only water needs to be added and mixed before use, significantly reducing the reliance on the experience of technical personnel for on-site construction. Its ease of operation facilitates its promotion and application.
[0020] In one technical solution of the present invention, in step S100, the stirring and mixing time is 2 min to 5 min.
[0021] Compared with existing technologies, the technical benefits achieved by this solution are as follows: a stirring time of 2-5 minutes is sufficient to ensure thorough and uniform mixing of the fine powder components. Too short a time results in uneven mixing, while too long a time reduces efficiency without providing additional benefits. This time window ensures both mixing quality and production efficiency.
[0022] In one technical solution of the present invention, in step S200, the stirring and mixing time is 3 min to 6 min.
[0023] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: after adding aggregates and fibers, a stirring time of 3-6 minutes allows the fibers to be fully dispersed in the dry mixing system without entanglement or agglomeration, while ensuring that the water-reducing agent and starch ether are uniformly attached to the particle surface, thus guaranteeing the rheological properties after subsequent water addition and mixing.
[0024] In one technical solution of the present invention, in step S300, the mixing and stirring time is 3 min-5 min.
[0025] Compared with existing technologies, the technical advantages achieved by this solution are as follows: a 3-5 minute water mixing time allows the dry-mixed powder to fully hydrate, forming a uniform, lump-free paste with optimal workability. If the mixing time is too short, hydration will be insufficient, limiting the development of mortar strength; if it is too long, the hydration reaction may occur prematurely, affecting the construction window.
[0026] To achieve the third objective of this invention, the technical solution of this invention provides an application of inorganic composite mortar, which is used for waterproofing and sealing the roots of building pipes by using inorganic composite mortar prepared by any of the above technical solutions or by any of the above technical solutions.
[0027] Compared with existing technologies, the technical effects achieved by this solution are as follows: This inorganic composite mortar can be directly applied and filled into the gaps at the base of pipes penetrating floors or walls, and then cured naturally at room temperature after compaction and smoothing. The mortar has an initial setting time of only 30-40 minutes, a final setting time of 60-80 minutes, and a 24-hour compressive strength ≥20MPa. It can quickly set and allows for early intervention of subsequent waterproofing processes. The hardening process exhibits micro-expansion characteristics, seamlessly adhering to pipes and the substrate, completely eliminating shrinkage cracks. It has an impermeability grade ≥P10, preventing dampness and leakage even after long-term immersion in water. Its bonding strength with concrete substrates is ≥0.95MPa, demonstrating excellent adhesion to various pipe materials such as PVC and galvanized steel pipes, eliminating the risk of hollow areas or detachment. Furthermore, this mortar is entirely inorganic, non-toxic, and odorless, making it suitable for enclosed indoor spaces such as kitchens, bathrooms, and basements. Applying this invention's mortar for sealing pipe roots can solve leakage, cracking, and detachment problems at their source, significantly improving the quality and construction efficiency of building waterproofing projects.
[0028] The technical solution provided by this invention can achieve at least one of the following effects: (1) Fast hardening and early strength, efficient construction: Through the dual cementitious system of fast hardening sulfoaluminate cement and hemihydrate desulfurized gypsum, the initial setting time of the mortar is only 30min-40min, the final setting time is 60min-80min, and the 24h compressive strength is ≥20MPa. It can be quickly shaped after construction, which greatly shortens the construction period and avoids sealing failure caused by subsequent disturbances. (2) Micro-expansion and crack resistance, waterproofing at the source: The synergistic effect of calcium oxide inorganic expansion agent and polypropylene fiber compensates for hardening shrinkage, making the mortar have micro-expansion characteristics, which can be seamlessly bonded to the pipes and the base layer, and completely eliminate shrinkage cracks; combined with active silica fume physical filling and organosilicon water-repellent agent chemical modification, the impermeability level reaches P10 or above, achieving long-term waterproofing. (3) High bonding strength, environmentally friendly and practical: the bonding strength with concrete base layer is ≥0.95MPa, and it is compatible with various pipe materials such as PVC and galvanized steel pipe. There is no hollowing or falling off; it is composed of all inorganic components, non-toxic and odorless, and easy to construct. It is suitable for indoor enclosed spaces such as kitchens, bathrooms and basements, and meets the requirements of green building materials. Detailed Implementation
[0029] The technical solutions of various embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments described in the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030]
Example 1
[0031] S200. Add refined quartz sand, polypropylene fiber, polycarboxylate superplasticizer, and hydroxypropyl starch ether to the first mixture, and continue stirring for 4 minutes until the mixture is homogeneous to obtain the second mixture.
[0032] S300. Mix the second mixture with water and organosilicon water-repellent agent, stir for 4 minutes until it becomes a paste without lumps, and obtain inorganic composite mortar.
[0033]
Example 2
[0034]
Example 3
[0035]
Example 4
[0036] Comparative Example 1 This comparative example provides an inorganic composite mortar, which differs from Example 1 in that it does not contain calcium oxide-based inorganic expanding agents or polypropylene fibers. All other components and preparation methods are the same as in Example 1.
[0037] Comparative Example 2 This comparative example provides an inorganic composite mortar, which differs from Example 1 in that it does not contain an organosilicon water-repellent agent. All other components and preparation methods are the same as in Example 1.
[0038] Comparative Example 3 This comparative example provides an inorganic composite mortar, which differs from Example 1 in that: rapid-hardening sulfoaluminate cement and hemihydrate desulfurized gypsum are replaced with an equal mass of ordinary 42.5 silicate cement. All other components and preparation methods are the same as in Example 1.
[0039] Comparative Example 4 This comparative example provides an inorganic composite mortar, which differs from Example 1 in that: rapid-hardening sulfoaluminate cement is used in 25 parts by weight, and hemihydrate desulfurized gypsum is used in 15 parts by weight. All other components and preparation methods are the same as in Example 1.
[0040] Performance testing: The mortars prepared in Examples 1-4 and Comparative Examples 1-4 were tested for performance in accordance with the "Standard for Basic Performance Test Methods of Building Mortar". The results are recorded in Table 1.
[0041] Table 1
[0042] According to the test results in the table above, the inorganic composite mortars provided in Examples 1-4 have an initial setting time of 32-38 minutes, a final setting time of 65-76 minutes, a 24-hour compressive strength of 20.2-22.8 MPa, and an impermeability grade of P10 or higher. The 28-day shrinkage rate is negative (-0.008% to -0.015%), exhibiting micro-expansion characteristics, and no cracking occurs after 28 days, showing a significant improvement in performance compared to the comparative examples. The inorganic composite mortars provided in these examples are significantly superior to comparative examples 1-4 in terms of setting speed, early strength, impermeability, and crack resistance. Examples 1, 2, and Comparative Example 4 show that when the ratio of rapid-hardening sulfoaluminate cement to hemihydrate desulfurized gypsum deviates from the range defined in this invention (cement less than 30 parts or gypsum more than 12 parts), the setting time is prolonged, the 24-hour compressive strength decreases, and fine cracks appear. This indicates that the ratio range of cement to gypsum is critical for achieving optimal performance. The inorganic composite mortars provided in Examples 1-4 are significantly superior to the comparative examples in terms of setting time, early strength, bond strength, impermeability grade, and shrinkage crack control. This proves that the present invention, through the dual cementitious system of rapid-hardening sulfoaluminate cement, hemihydrate desulfurized gypsum, the synergistic micro-expansion crack resistance of inorganic expanding agent and polypropylene fiber, and the dual waterproof barrier of active silica fume and organosilicon water-repellent agent, successfully solves the technical problems of slow setting, shrinkage cracking, poor impermeability, and weak bonding of existing pipe root sealing materials.
[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects. The scope of the invention is defined by the appended claims, not by the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No markings in the claims should be construed as limiting the scope of the claims.
[0044] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. An inorganic composite mortar, characterized in that, By weight, it includes: Rapid-hardening sulfoaluminate cement, 30-40 parts; Hemihydrate desulfurized gypsum, 8-12 parts; Refined quartz sand, 30-35 parts; Activated silica fume, 2-8 parts; Organosilicon water-repellent agent, 0.2-0.6 parts; Inorganic expanding agent based on calcium oxide, 0.2-0.8 parts; Polypropylene fiber, 0.1-0.2 parts; Polycarboxylate superplasticizer, 0.2-0.3 parts; Hydroxypropyl starch ether, 0.06-0.1 parts; Water, 15-30 parts.
2. The inorganic composite mortar according to claim 1, characterized in that, The fineness of the active silica fume is ≥900 mesh.
3. The inorganic composite mortar according to claim 1, characterized in that, The length of the polypropylene fiber is 2mm-4mm.
4. The inorganic composite mortar according to claim 1, characterized in that, The refined quartz sand has a mesh size of 40-70 mesh.
5. The inorganic composite mortar according to claim 1, characterized in that, The initial setting time of the inorganic composite mortar is 30-40 minutes, the final setting time of the inorganic composite mortar is 60-80 minutes, the 24-hour compressive strength of the inorganic composite mortar is ≥20 MPa, and the impermeability grade of the inorganic composite mortar is ≥P10.
6. A method for preparing inorganic composite mortar as described in any one of claims 1-5, characterized in that, Includes the following steps: S100, Dry material mixing: Add rapid-hardening sulfoaluminate cement, hemihydrate desulfurization gypsum, active silica fume, and calcium oxide inorganic expansion agent to the mixer according to the mass parts, and mix to obtain the first mixture; S200, Compound Mixing: Add refined quartz sand, polypropylene fiber, polycarboxylate superplasticizer, and hydroxypropyl starch ether to the first mixture, and continue stirring and mixing to obtain the second mixture; S300, On-site mixing: The second mixture is mixed with water and organosilicon water-repellent agent until it becomes a paste to obtain the inorganic composite mortar.
7. The method for preparing inorganic composite mortar according to claim 6, characterized in that, In step S100, the mixing time is 2 min to 5 min.
8. The method for preparing inorganic composite mortar according to claim 6, characterized in that, In step S200, the mixing time continues for 3-6 minutes.
9. The method for preparing inorganic composite mortar according to claim 6, characterized in that, In step S300, the mixing and stirring time is 3 min to 5 min.
10. An application of an inorganic composite mortar, characterized in that, Inorganic composite mortar prepared by any one of claims 1-5 or by any one of claims 6-9 is used for waterproofing and sealing the roots of building pipes.