Method for developing grouting material for rapid connection system of fully assembled bridge

Abstract

The present invention relates to the technical field of grouting materials, and provides a method for developing a grouting material for a rapid connection system of a fully assembled bridge, comprising the following steps: study on optimization of the compatibility of nano-silica fume-cement-admixture; calculation and construction of a nano-silica fume-cement-admixture-aggregate close-packed system; design of the preparation process and mix ratio of a rapid-hardening grouting material; study on the rheological properties and rheological mechanism of the rapid-hardening grouting material; study on the influence patterns of parameters on the hourly strength and volume stability of the rapid-hardening grouting material; and construction of a microstructure model for the rapid-hardening grouting material. The grouting material developed by the present invention exhibits significant advantages in terms of hardening time, flowability, early strength, volume stability, impermeability and durability, and the like, and can meet the requirements of rapid connection systems for fully assembled bridges, thereby improving the efficiency and quality of bridge construction.

Description

Preparation method of grouting material suitable for rapid connection system of full assembly bridge TECHNICAL FIELD

[0001] The present application relates to the technical field of grouting material, and particularly relates to a preparation method of grouting material suitable for a rapid connection system of full assembly bridge. BACKGROUND

[0002] With the rapid development of infrastructure construction in China, bridge construction, as an important part, has attracted widespread attention in terms of construction speed and quality. The traditional bridge construction method often requires a large amount of manpower and material resources, and the construction period is long, which to some extent limits the efficiency of bridge construction. In order to solve this problem, full assembly bridge structure emerges as the times require. This structure uses prefabricated components, such as prefabricated pier columns and prefabricated cap beams, which are quickly and safely connected through grouting material, greatly improving the efficiency of bridge construction. However, the quality of grouting material directly affects the safety and reliability of the bridge, so it is of great significance to develop a fast-hardening grouting material suitable for the rapid connection system of full assembly bridge.

[0003] At present, there are some grouting material products on the market that can be used for the connection of full assembly bridges. These grouting materials are mainly composed of cement, sand, gravel and other materials, and have certain adhesion and strength. However, the performance of these grouting materials is not ideal, for example, the setting time is slow, the flow loss is large, the early strength is low, and the late hardening will shrink, etc. These problems may affect the safety and reliability of the bridge.

[0004] Although the existing grouting material can meet the needs of bridge construction to some extent, it still has some problems and shortcomings. First, the existing grouting material has a slow setting time, which will affect the construction efficiency. Second, the existing grouting material has a large flow loss, which may affect the filling effect of the grouting material, thereby affecting the connection quality of the bridge. In addition, the existing grouting material has a low early strength, which may affect the bearing capacity of the bridge. Finally, the existing grouting material will shrink in the late hardening, which may cause cracks in the bridge structure and affect the service life of the bridge. Therefore, it is urgent to develop a new type of grouting material to solve the problems of existing grouting materials. SUMMARY

[0005] In view of the above prior art, the present application provides a preparation method of grouting material suitable for a rapid connection system of full assembly bridge.

[0006] The present invention provides a method for developing grouting material suitable for rapid connection system of fully prefabricated bridges, comprising the following steps: compatibility optimization study of nano-silica fume-cement-admixture: by studying the dispersibility of nanomaterials in aqueous system and optimizing the compatibility of nano-silica fume-cement-admixture, the fluidity and adhesion of grouting material are improved, thereby improving the filling effect of grouting material and the connection quality of bridge.

[0007] Calculation and construction of a close-packed system of nano-silica fume-cement-admixture-aggregate: By calculating and constructing a close-packed system of "nano-silica fume-cement-admixture-aggregate", the grouting material can be made to achieve rapid setting and hardening, improve the early strength of the grouting material, and thus improve the load-bearing capacity and service life of the bridge.

[0008] Preparation process and mix design of fast-setting grout: By designing the preparation process and mix design of fast-setting grout, the grout can be made to set and harden quickly, improve its early strength, and thus improve the load-bearing capacity and service life of the bridge.

[0009] Rheological properties and mechanisms of fast-setting grouts: By studying the rheological properties and mechanisms of fast-setting grouts, we aim to achieve rapid setting and hardening of grouts, improve their early strength, and thus enhance the load-bearing capacity and service life of bridges.

[0010] Influence of various parameters on the hourly strength and volume stability of rapid-setting grout: By studying the influence of various parameters on key performance indicators such as hourly strength and volume stability of rapid-setting grout, we aim to achieve rapid setting and hardening of the grout, improve its early strength, and thus enhance the load-bearing capacity and service life of bridges.

[0011] Construction of microstructure model of fast-setting grout: By constructing a microstructure model of fast-setting grout, the grout can be made to achieve rapid setting and hardening, improve the early strength of the grout, and thus improve the load-bearing capacity and service life of bridges.

[0012] Preferably, to improve the fluidity and adhesion of the grouting material, thereby enhancing the connection quality of the bridge, this invention focuses on optimizing the compatibility of the nano-silica fume-cement-admixture system. First, by thoroughly studying the dispersibility of nanomaterials in an aqueous system, techniques such as ultrasonic dispersion, surfactant modification, and nanomaterial surface modification are employed to improve the dispersibility of nanomaterials in the aqueous system. Based on this, the compatibility of the nano-silica fume-cement-admixture system is further optimized, thereby effectively improving the filling effect of the grouting material and the connection quality of the bridge. Specific methods for optimizing the compatibility of the nano-silica fume-cement-admixture system include: 1) using nanomaterial surface modification technology to improve the interfacial adhesion between the nanomaterials and the cement matrix; 2) optimizing the compatibility of the nano-silica fume-cement-admixture system by adjusting parameters such as particle size, morphology, and surface charge of the nanomaterials and silica fume; 3) utilizing ultrasonic dispersion technology to improve the uniform dispersion of nanomaterials and admixtures in the aqueous system; and 4) improving the interfacial interaction between the nanomaterials and admixtures by adding an appropriate amount of surfactant, thereby enhancing the adhesion of the grouting material. By comprehensively applying the above technical means, the compatibility of the nano-silica fume-cement-admixture system can be optimized, thereby improving the fluidity and adhesion of the grout and enhancing the connection quality of the bridge.

[0013] Preferably, in order to achieve rapid setting and hardening of the grout and improve its early strength, this invention optimizes the microstructure of the material by calculating and constructing a "nano-silica fume-cement-admixture-aggregate" close-packed system, thereby improving the load-bearing capacity and service life of the bridge. The specific methods for calculating and constructing the nano-silica fume-cement-admixture-aggregate close-packed system include: 1) applying close-packing theory, using computer simulation and optimization of the volume fraction and particle arrangement of nano-silica fume-cement-admixture-aggregate to achieve close packing and improve its mechanical properties; 2) optimizing the compatibility of the nano-silica fume-cement-admixture system by adjusting parameters such as particle size, morphology, and surface charge of the nanomaterials and silica fume, thereby improving the close packing effect; 3) utilizing ultrasonic dispersion technology to improve the uniform dispersion of nanomaterials and admixtures in the aqueous system, thereby improving the degree of close packing; 4) adding an appropriate amount of surfactant to improve the interfacial interaction between nanomaterials and admixtures, thereby improving the adhesion and early strength of the grout. By comprehensively applying the above technologies, the optimized construction of a "nano-silica fume-cement-admixture-aggregate" compact packing system can be achieved, thereby improving the rapid setting and hardening performance and early strength of the grout, and enhancing the load-bearing capacity and service life of the bridge.

[0014] Preferably, in order to achieve rapid setting and hardening of the grout and improve its early strength, this invention focuses on the preparation process and mix design of the rapid-setting grout. By precisely controlling the proportions and addition order of components such as cement, nanomaterials, silica fume, admixtures, and aggregates, the microstructure and performance of the grout are optimized. The specific methods for the preparation process and mix design of the rapid-setting grout include: 1) selecting high-efficiency water-reducing agents and early-strength agents, and adjusting the water-cement ratio to improve the early strength of the grout; 2) rationally designing the dosage of nanomaterials and silica fume, utilizing their excellent physical and chemical properties to improve the microstructure of the grout and achieve rapid setting and hardening; 3) optimizing the ratio of admixtures and aggregates to improve the compact packing effect of the grout, thereby improving its mechanical properties; 4) employing advanced preparation processes, such as ultrasonic dispersion and mechanical stirring, to ensure the uniform dispersion of nanomaterials and admixtures in the grout. By comprehensively applying the above technical means, the optimized preparation of fast-setting grouting materials can be achieved, thereby improving the fast-setting and hardening performance and early strength of the grouting materials, and enhancing the load-bearing capacity and service life of bridges.

[0015] Preferably, to achieve rapid setting and hardening of the fast-setting grout and improve its early strength, this invention focuses on the rheological properties and rheological mechanism of the grout. Specific methods for studying the rheological properties and mechanism of the fast-setting grout include: 1) studying the rheological properties of the grout under different ages and stress conditions using equipment such as a dynamic shear rheometer to reveal its rheological mechanism; 2) utilizing the excellent physical and chemical properties of nanomaterials and silica fume to improve the microstructure of the grout and enhance its initial fluidity and shear strength; 3) adjusting the fluidity and equilibrium stress of the grout by rationally designing the water-cement ratio and dosage to achieve rapid setting and hardening; 4) studying the influence of early-strength agents and high-efficiency water-reducing agents on the rheological properties of the grout, optimizing the mix proportion, and improving the early strength of the grout. Through the comprehensive application of the above techniques, the rheological properties of the fast-setting grout can be optimized, thereby improving its rapid setting and hardening performance and early strength, and enhancing the load-bearing capacity and service life of bridges.

[0016] Preferably, to achieve rapid setting and hardening of the fast-setting grout and improve its early strength, this invention focuses on the influence of various parameters on key performance indicators such as hourly strength and volume stability of the grout. Specific methods for understanding the influence of these parameters on the hourly strength and volume stability of the fast-setting grout include: 1) studying the influence of each component on the hourly strength and volume stability of the grout by changing the proportions and addition order of cement, nanomaterials, silica fume, admixtures, and aggregates; 2) studying the influence of the water-cement ratio and dosage on the hourly strength and volume stability of the grout by adjusting them; 3) studying the influence of early-strength agents and high-efficiency water-reducing agents on the hourly strength and volume stability of the grout, and optimizing the mix proportions; 4) studying the influence of curing conditions on the hourly strength and volume stability of the grout by controlling curing temperature and humidity. Through the comprehensive application of these techniques, the key performance indicators of the fast-setting grout can be optimized, thereby improving its rapid setting and hardening performance and early strength, and enhancing the load-bearing capacity and service life of bridges.

[0017] Preferably, to achieve rapid setting and hardening of the fast-setting grout and improve its early strength, this invention focuses on constructing a microstructure model of the fast-setting grout. The specific method for constructing the microstructure model of the fast-setting grout includes: 1) using advanced microstructure analysis techniques, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD), to study the microstructure characteristics of the fast-setting grout; 2) based on the microstructure characteristics, constructing a microstructure model of the fast-setting grout to reveal the relationship between its microstructure and performance; 3) improving the microstructure of the grout by optimizing the proportions and addition order of components such as nanomaterials, silica fume, admixtures, and aggregates, thereby achieving rapid setting and hardening; 4) using the microstructure model to guide the preparation and optimization of the fast-setting grout, improving its early strength. Through the comprehensive application of the above techniques, the construction of a microstructure model of the fast-setting grout can be achieved, thereby improving the rapid setting and hardening performance and early strength of the grout, and enhancing the load-bearing capacity and service life of bridges.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The development of fast-setting grouting material has solved the problem of slow setting time of existing grouting materials, which can greatly improve construction efficiency and meet the needs of rapid connection system of fully prefabricated bridges.

[0020] 2. The grouting material of the present invention has excellent fluidity, which can effectively fill the grouting sleeve and avoid the filling effect of the grouting material being affected by the large loss of fluidity over time, thereby improving the connection quality of the bridge.

[0021] 3. The grouting material of the present invention has high early strength and can reach sufficient strength in a short time to meet the load-bearing capacity requirements of bridges and improve the safety of bridges.

[0022] 4. The grouting material of the present invention has good volume stability and will not shrink during the later hardening process, thus avoiding cracks in the bridge structure and improving the service life of the bridge.

[0023] 5. The grouting material of the present invention has excellent impermeability and durability, effectively preventing the intrusion of chloride ions and improving the durability of bridges.

[0024] In summary, the grouting material developed in this invention has significant advantages in terms of hardening time, fluidity, early strength, volume stability, and impermeability durability, which can meet the needs of the rapid connection system of fully prefabricated bridges and improve the efficiency and quality of bridge construction. Detailed Implementation

[0025] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0026] Example: A method for developing a grouting material suitable for a rapid connection system of fully prefabricated bridges:

[0027] Step 1: Mix the nanomaterials, silica fume, cement and admixtures in a mass ratio of 1:1:2:1 for 30 minutes at a speed of 500 rpm to obtain mixture A.

[0028] Step 2: Mix mixture A with aggregate at a mass ratio of 1:3 for 60 minutes at a speed of 700 rpm to obtain mixture B.

[0029] Step 3: Mix mixture B with water at a mass ratio of 1:0.5, mix for 90 minutes at a speed of 800 rpm to obtain a fast-setting grout.

[0030] Step 4: Conduct performance tests on the obtained fast-setting grout, including performance indicators such as compressive strength, fluidity, vertical expansion rate, initial setting time, final setting time, and chloride ion content.

[0031] Step 5: Based on the test results, adjust the proportions of nanomaterials, silica fume, cement, admixtures and aggregates, as well as the amount of water, to optimize the performance of the fast-setting grout.

[0032] Step Six: Repeat steps one through five until the performance of the fast-setting grout meets the requirements, namely, compressive strength ≥ 60 MPa after 12 hours of hardening, compressive strength ≥ 100 MPa after 28 days of hardening, initial fluidity ≥ 300 mm, fluidity retention ≥ 260 mm after 30 minutes, vertical expansion rate of 0.02-2% after 3 hours, and the difference between 24 hours and 3 hours is 0.02-0.4%. The initial setting time and final setting time should be adjusted according to the needs of on-site construction within the ranges of 30 minutes to 1 hour and 1.5 hours to 6.5 hours, respectively. The chloride ion content should be ≤ 0.03%, with no bleeding, a bleeding rate of 0%, and excellent water resistance.

[0033] The above are the specific operation steps of this embodiment. Through this method, fast-setting grouting material that meets the requirements can be prepared for use in the rapid connection system of fully prefabricated bridges, thereby improving the construction efficiency and service life of bridges.

[0034] This embodiment has wide applications in civil engineering, building structures, and materials science. The rapid development of fully prefabricated bridge structures has led to an increasing demand for grouting materials. However, existing grouting materials have many problems and drawbacks, such as slow setting time, significant loss of fluidity over time, low early strength, and shrinkage during later hardening. Therefore, developing a new type of grouting material to solve the problems of existing grouting materials is of significant practical importance and market demand. The fast-setting grouting material of this embodiment has advantages such as rapid setting and hardening, high hourly strength, volume stability, and impermeability and durability. It can effectively solve the problems of existing grouting materials, improve the efficiency and quality of bridge construction, extend the service life of bridges, and has broad market prospects.

[0035] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structures made using the content of the present invention specification, whether directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A method for developing a grouting material suitable for a rapid connection system of fully prefabricated bridges, characterized in that, The process includes the following steps: compatibility optimization study of nano-silica fume-cement-admixture, calculation and construction of nano-silica fume-cement-admixture-aggregate close packing system, preparation process and mix design of fast-setting grout, rheological properties and rheological mechanism of fast-setting grout, influence of various parameters on hourly strength and volume stability of fast-setting grout, and construction of microstructure model of fast-setting grout.

2. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1, characterized in that, The specific methods for optimizing the compatibility of the nano-silica fume-cement-admixture system include: 1) using nanomaterial surface modification technology to improve the interfacial adhesion between nanomaterials and cement matrix; 2) optimizing the compatibility of the nano-silica fume-cement-admixture system by adjusting parameters such as particle size, morphology, and surface charge of nanomaterials and silica fume; 3) using ultrasonic dispersion technology to improve the uniform dispersion of nanomaterials and admixtures in aqueous systems; and 4) improving the interfacial interaction between nanomaterials and admixtures and increasing the adhesion of grouting material by adding an appropriate amount of surfactant.

3. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1 or 2, characterized in that, The specific methods for calculating and constructing the nano-silica fume-cement-admixture-aggregate close-packed system include: 1) using close-packing theory, through computer simulation and optimization of the volume fraction and particle arrangement of nano-silica fume-cement-admixture-aggregate, to achieve close packing of materials and improve their mechanical properties; 2) by adjusting parameters such as particle size, morphology, and surface charge of nanomaterials and silica fume, optimizing the compatibility of the nano-silica fume-cement-admixture system, and improving the close packing effect of materials; 3) using ultrasonic dispersion technology to improve the uniform dispersion of nanomaterials and admixtures in the aqueous system, thereby improving the degree of close packing of materials; 4) by adding an appropriate amount of surfactant, improving the interfacial interaction between nanomaterials and admixtures, and improving the adhesion and early strength of the grout.

4. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1 or 2, characterized in that, The specific methods for preparing and designing the mix proportion of the fast-setting grout include: 1) selecting high-efficiency water-reducing agents and early-strength agents, and adjusting the water-cement ratio to improve the early strength of the grout; 2) improving the microstructure of the grout by rationally designing the dosage of nanomaterials and silica fume, utilizing their excellent physical and chemical properties to achieve rapid setting and hardening; 3) optimizing the mixing ratio of admixtures and aggregates to improve the compact packing effect of the grout, thereby improving its mechanical properties; 4) adopting advanced preparation processes, such as ultrasonic dispersion and mechanical stirring, to ensure the uniform dispersion of nanomaterials and admixtures in the grout.

5. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1 or 2, characterized in that, The specific methods for studying the rheological properties and mechanisms of the rapid-setting grout include: 1) using equipment such as a dynamic shear rheometer to study the rheological properties of the grout under different ages and stress conditions, and revealing its rheological mechanism; 2) utilizing the excellent physical and chemical properties of nanomaterials and silica fume to improve the microstructure of the grout and enhance its initial fluidity and shear strength; 3) adjusting the fluidity and equilibrium stress of the grout by rationally designing the water-cement ratio and dosage, thereby achieving rapid setting and hardening of the grout; 4) studying the effects of early-strength agents and high-efficiency water-reducing agents on the rheological properties of the grout, optimizing the mix proportion, and improving the early strength of the grout.

6. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1 or 2, characterized in that, The specific methods for studying the influence of the parameters on the hourly strength and volume stability of the rapid-hardening grout include: 1) studying the influence of each component on the hourly strength and volume stability of the grout by changing the proportion and addition order of cement, nanomaterials, silica fume, admixtures and aggregates; 2) studying the influence of water-cement ratio and dosage on the hourly strength and volume stability of the grout by adjusting the water-cement ratio and dosage; 3) studying the influence of early-strength agents and high-efficiency water-reducing agents on the hourly strength and volume stability of the grout, and optimizing the mix proportion; 4) studying the influence of curing conditions on the hourly strength and volume stability of the grout by controlling curing temperature and humidity.

7. The method for developing grouting material suitable for rapid connection systems of fully prefabricated bridges as described in claim 1 or 2, characterized in that, The specific methods for constructing the microstructure model of the fast-setting grout include: 1) using advanced microstructure analysis technology to study the microstructure characteristics of the fast-setting grout; 2) based on the microstructure characteristics, constructing a microstructure model of the fast-setting grout to reveal the relationship between its microstructure and performance; 3) improving the microstructure of the grout by optimizing the proportion and addition order of components such as nanomaterials, silica fume, admixtures and aggregates to achieve rapid setting and hardening; 4) using the microstructure model to guide the preparation and optimization of the fast-setting grout and improve its early strength.