A structure, method and flowing mortar formulation for reinforcing low strength concrete structures

Abstract

The application relates to a structure, a method and a flowing mortar formula for reinforcing a low-strength concrete building, the low-strength concrete building comprising original low-strength concrete beams and an original low-strength concrete plate, the two original low-strength concrete beams being arranged at the bottom of the original low-strength concrete plate on both sides, the inner sides of the two original low-strength concrete beams being provided with prefabricated L-shaped plates with stoppers, the inner sides of the two walls of the prefabricated L-shaped plates with stoppers corresponding to the bottom and the inner side wall of the original low-strength concrete beam respectively, and gaps being left between the prefabricated L-shaped plates with stoppers and the original low-strength concrete beams; the top of the two prefabricated L-shaped plates with stoppers being provided with a prefabricated concrete top plate with stoppers, and a gap being left between the prefabricated concrete top plate with stoppers and the original low-strength concrete plate; and the gap being filled with flowing mortar; the structure can significantly improve the bearing capacity of the structure while meeting the requirement of not changing the outer facade, and the original features of the building are maximally reserved.

Description

Technical Field

[0001] This invention relates to a structure, method, and flowable mortar formula for reinforcing low-strength concrete buildings, belonging to the field of building structure technology. Background Technology

[0002] Due to environmental factors and the length of their service life, concrete load-bearing components are highly susceptible to defects such as protective layer detachment, internal steel reinforcement corrosion, and low residual concrete strength. Because these buildings hold significant historical value, a suitable method for reinforcement is urgently needed. Properly reinforced concrete structures can not only meet safety requirements but also adapt well to the demands of modern building construction.

[0003] Chinese patent CN114991517A discloses a three-dimensional embedded reinforcement system and construction method for FRP (fiberglass reinforced plastic) bars that can preserve the original appearance of a building. The system includes a three-dimensional support frame embedded in the mortar joints of a masonry structure. The three-dimensional support frame consists of anchoring components and reinforcement components. The anchoring components can use different styles of anchors depending on the specific masonry structure being reinforced. The reinforcement components include multiple first and second reinforcing bars. The L-shaped anchors are used at the corners of the masonry, and each of the two outer walls of the L-shaped anchor has a first groove, the diameter of which is matched to the diameter of the first and second reinforcing bars. However, this invention, by setting anchoring components and embedding FRP bars in the brick joints, will cause inconsistencies in the original concrete surface appearance and may also present durability issues.

[0004] Currently, common reinforcement methods for ordinary concrete structures include cross-section enlargement, steel cladding, steel plate bonding, FRP bonding, and prestressed reinforcement. Among these methods, cross-section enlargement and steel cladding are particularly suitable for reinforcing low-strength concrete members. However, for members with concrete strength below C15 or C10, conventional structural reinforcement methods such as steel cladding and FRP bonding are not applicable. How to reinforce low-strength concrete buildings without altering their original appearance remains a challenge.

[0005] Therefore, a technology and process for reinforcing low-strength concrete structures is needed to solve the above problems. Summary of the Invention

[0006] To address the aforementioned problems in the existing technology, this invention provides a structure, method, and flowing mortar formula for reinforcing low-strength concrete buildings. This method can significantly improve the load-bearing capacity of the structure without altering the facade, and maximizes the preservation of the original appearance of the building.

[0007] The technical solution of the present invention is as follows:

[0008] A formula for a flowable mortar for reinforcing low-strength concrete buildings, comprising by weight 57.7 parts grout, 11.3 parts water, 23.1 parts sand, 3.9 parts acrylic polymer emulsion, and 4 parts microbial remediation agent.

[0009] The microbial repair agent is an additive with Bacillus as its main component.

[0010] A method for reinforcing low-strength concrete building structures includes original low-strength concrete beams and original low-strength concrete slabs. Two original low-strength concrete beams are positioned on either side of the bottom of the original low-strength concrete slab. Precast L-shaped slabs with prefabricated stop-type plates are installed inside the two original low-strength concrete beams. The two inner walls of the precast L-shaped slabs correspond to the bottom and inner walls of the original low-strength concrete beams, respectively, with a gap between the precast L-shaped slabs and the original low-strength concrete beams. A precast concrete top slab with prefabricated stop-type plates is mounted on top of the two precast L-shaped slabs, with a gap between the precast concrete top slab and the original low-strength concrete slab. The gap is filled with flowing mortar.

[0011] The precast concrete roof slab includes two "L"-shaped basic components and several "Z"-shaped basic components spliced ​​together. The upper half of one end of the "Z"-shaped basic component protrudes by a section, and the lower half of the other end protrudes by a section to form an interlocking part. Adjacent "Z"-shaped basic components interlock and are fixed together. The "L"-shaped basic components and "Z"-shaped basic components at both ends interlock and are fixed together.

[0012] The precast concrete top slab with a stop is located on both sides and abuts against the inner walls of the original low-strength concrete beams on both sides.

[0013] Bolt holes are provided on the bottom and sides of the precast L-shaped slab and the original low-strength concrete beam, and bolt holes are provided vertically on the precast L-shaped slab and the original low-strength concrete slab. The precast L-shaped slab and the original low-strength concrete beam, as well as the precast L-shaped slab and the original low-strength concrete slab, are fixed by bolts passing through the pre-set bolt holes.

[0014] FRP steel bars are provided in the gaps, which are placed along the overall length.

[0015] The precast L-shaped slab with precast stop and the precast concrete top slab with precast stop are made of high-strength concrete and wire mesh.

[0016] A method for reinforcing low-strength concrete structures includes the following steps:

[0017] S1: Bolt holes are vertically installed at the corresponding positions of the precast concrete top slab and the original low-strength concrete slab. Bolt holes are drilled at the bottom and sides of the precast L-shaped slab and the original low-strength concrete beam.

[0018] S2: Install the prefabricated L-shaped plate with a stop on the side of the original low-strength concrete beam. The two inner walls of the prefabricated L-shaped plate with a stop correspond to the bottom and inner wall of the original low-strength concrete beam, respectively. There is a gap between the prefabricated L-shaped plate with a stop and the original low-strength concrete beam. The plate is fixed by bolts through the pre-set bolt holes. At the same time, a suitable distance is maintained between the top of the prefabricated L-shaped plate and the bottom of the original low-strength concrete beam.

[0019] S3: Place FRP steel bars in the gap between the bottom of the original low-strength concrete beam and the precast L-shaped plate. Start pouring flowing mortar from the top of the inner wall of the original low-strength concrete beam downwards, so that the flowing mortar fills the gap between the precast L-shaped plate and the original low-strength concrete beam. Wait for the flowing mortar to reach the expected strength.

[0020] S4: A precast concrete top slab is erected on top of the precast L-shaped slab with a precast stop. A gap is left between the precast concrete top slab with a precast stop and the original low-strength concrete slab. The precast concrete top slab with a precast stop and the original low-strength concrete slab are fixed by bolts passing through the pre-set bolt holes.

[0021] S5: Place the FRP steel bars between the precast stop-type concrete top slab and the original low-strength concrete slab, and at the same time open grouting holes in the original low-strength concrete slab.

[0022] S6: Inject flowing mortar through the reserved grouting holes, and cure for a period of time until the flowing mortar reaches the predetermined strength, at which point the reinforcement is complete.

[0023] In step S4, the two ends of the precast stop-type concrete top slab are tightly attached to the inner wall of the original low-strength concrete slab.

[0024] The present invention has the following beneficial effects:

[0025] This invention utilizes specially formulated flowing mortar for grouting, achieving a superior reinforcement effect. Furthermore, it incorporates prefabricated L-shaped slabs and prefabricated concrete roof slabs with prefabricated stop joints on the inner side of low-strength concrete structures. These slabs and roof slabs are constructed from high-strength concrete and wire mesh, thus solving the problem of traditional reinforcement methods being difficult to apply to low-strength structural components and possessing significant practical value.

[0026] Meanwhile, for historical buildings, their floor plans may be irregular. The precast stop-type concrete roof slab of this device is made of "L"-shaped basic components at both ends and several "Z"-shaped basic components in the middle. It can be used on uneven building surfaces while having strong structural strength. Furthermore, it is bonded by flowing mortar, which keeps the structural strength stable. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram showing the ungrouted area between the precast concrete top slab with a stop and the original low-strength concrete slab of the present invention.

[0029] Figure 3 This is a schematic diagram of the installation of the prefabricated L-shaped plate with a stop in the present invention;

[0030] Figure 4 This is a schematic diagram of the overall structure of the prefabricated stop-type concrete roof slab of the present invention;

[0031] Figure 5 This is a schematic diagram of the basic "Z"-shaped component structure of the present invention.

[0032] The reference numerals in the figure are as follows:

[0033] 1. Precast L-shaped slab with precast stop; 2. Original low-strength concrete beam; 3. Precast concrete roof slab with precast stop; 4. Original low-strength concrete slab; 5. FRP reinforcement; 6. Flowing mortar; 7. Grouting holes; 8. Bolts. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] Please see Figures 1 to 5 The invention provides a technical solution:

[0036] A method for reinforcing low-strength concrete building structures includes original low-strength concrete beams 2 and two original low-strength concrete slabs 4. The two original low-strength concrete beams 2 are located on both sides of the bottom of the original low-strength concrete slabs 4. The original low-strength concrete beams 2 and the two original low-strength concrete slabs 4 are integrally formed, creating a U-shape. Precast L-shaped plates 1 with precast stop openings are provided on the inner sides of the two original low-strength concrete beams 2. The two inner walls of the precast L-shaped plates 1, i.e., the two walls on the "L"-shaped opening side of the precast L-shaped plates 1, respectively correspond to... A gap is left between the bottom and inner wall of the original low-strength concrete beam 2, the precast L-shaped plate 1 with a stop, and the bottom and sides of the precast L-shaped plate 1 and the original low-strength concrete beam 2. Bolt holes are provided on the bottom and sides of both the precast L-shaped plate 1 and the original low-strength concrete beam 2. The precast L-shaped plate 1 and the original low-strength concrete beam 2 are fixed by bolts 8 passing through the pre-set bolt holes. A precast concrete top plate 3 is mounted on top of the two precast L-shaped plates 1. The left and right side walls of the precast concrete top plate 3 are tightly fitted to the inner walls of the two original low-strength concrete beams 2, i.e., the two... On the sidewall of the original low-strength concrete beam 2 facing each other, similarly, a gap is left between the precast concrete top slab 3 and the original low-strength concrete slab 4. Vertical bolt holes are provided on both the precast concrete top slab 3 and the original low-strength concrete slab 4, and the precast concrete top slab 3 and the original low-strength concrete slab 4 are fixed by bolts 8 passing through the pre-set bolt holes. The gaps between the precast L-shaped slab 1 and the original low-strength concrete beam 2, and between the precast concrete top slab 3 and the original low-strength concrete slab 4, are all provided with bolts along the entire length. FRP steel bars 5 are placed along the length, and the gaps are filled with flowing mortar 6. After the flowing mortar 6 is poured in, it can form a good bond with the FRP steel bars 5, ensuring that the precast L-shaped slab 1 and the precast concrete top slab 3 can be connected as a whole with the two original low-strength concrete beams 2 and the original low-strength concrete slab 4, and work together. The precast L-shaped slab 1 and the precast concrete top slab 3 are made of high-strength concrete and wire mesh, avoiding the adverse effects on the original appearance caused by conventional reinforcement methods such as steel bonding and carbon cloth application.

[0037] As a preferred option, such as Figure 4 As shown, the precast concrete roof slab 3 consists of two "L"-shaped basic components at both ends and several "Z"-shaped basic components in the middle. The upper half of one end of the "Z"-shaped basic component protrudes by one section, and the lower half of the other end protrudes by one section to form an interlocking part. Adjacent "Z"-shaped basic components interlock and are fixed together, and the "L"-shaped basic components at both ends interlock and are fixed together with the "Z"-shaped basic components.

[0038] A formulation for reinforcing low-strength concrete building flowable mortar used in this structure, the flowable mortar 6 includes the following components: grout, water, sand, acrylic polymer emulsion, and microbial repair agent. The microbial repair agent is an additive with Bacillus as the main component, accounting for 3% to 5% by mass. This microorganism can produce carbonates during its metabolism; the continuous synthesis and accumulation of carbonates achieves the effect of repairing cracks. The acrylic polymer emulsion plays two roles: firstly, adding acrylic emulsion to the flowable mortar 6 can reduce the strength of the flowable mortar 6, resulting in a decrease in strength between "original low-strength concrete slab 4 – flowable mortar 6 – precast stop-type concrete roof slab 3" and "original low-strength concrete beam 2 – flowable mortar 6 – precast stop-type L-shaped slab 1," thus preventing excessive stiffness of the reinforced structure from reducing its ductility. Secondly, the acrylic emulsion can enhance the viscosity of the flowing mortar 6, further enhancing the bond between the original structure and the reinforcing material; the flowing mortar 6 can effectively connect the existing original low-strength concrete beam 2 with the precast L-shaped slab 1, as well as connect the existing original low-strength concrete slab 4 with the precast L-shaped concrete roof slab 3, and can also be used as a new floor slab or beam to bear the load.

[0039] Specifically, the flowing mortar 6 parts by weight includes 57.7 parts grout, 11.3 parts water, 23.1 parts sand, 3.9 parts acrylic polymer emulsion, and 4 parts microbial remediation agent.

[0040]

[0041] The tests were conducted according to GB50448-2015 and JGJ / T 70-2009 standards, and the test data are as follows:

[0042] Compressive strength (MPa) 37.5 Tensile bond strength (MPa) 2.39

[0043] The reinforcement work steps are as follows:

[0044] A method for reinforcing low-strength concrete structures includes the following steps:

[0045] S1: Bolt holes are vertically installed at the corresponding positions of the precast concrete top slab 3 and the original low-strength concrete slab 4. Bolt holes are drilled at the bottom and sides of the precast L-shaped slab 1 and the original low-strength concrete beam 2.

[0046] S2: Install the prefabricated L-shaped plate 1 on the side of the original low-strength concrete beam 2. The two inner walls of the prefabricated L-shaped plate 1 correspond to the bottom and inner wall of the original low-strength concrete beam 2, respectively. There is a gap between the prefabricated L-shaped plate 1 and the original low-strength concrete beam 2. The plate is fixed by bolts 8 through the pre-set bolt holes. At the same time, a suitable distance is maintained between the top of the prefabricated L-shaped plate 1 and the bottom of the original low-strength concrete plate 4.

[0047] S3: Place FRP steel bars 5 in the gap between the bottom of the original low-strength concrete beam 2 and the precast L-shaped plate 1. Start pouring flowing mortar 6 from the top of the inner wall of the original low-strength concrete beam 2 downwards, so that the flowing mortar 6 fills the gap between the precast L-shaped plate 1 and the original low-strength concrete beam 2. Wait for the flowing mortar 6 to reach the expected strength.

[0048] S4: A precast concrete top slab 3 with a precast stop is erected on top of the precast L-shaped slab 1. A gap is left between the precast concrete top slab 3 with a precast stop and the original low-strength concrete slab 4. The two ends of the precast concrete top slab 3 are tightly attached to the inner sidewall of the original low-strength concrete slab 4. The precast concrete top slab 3 with a precast stop and the original low-strength concrete slab 4 are fixed by bolts 8 passing through the pre-set bolt holes.

[0049] S5: Place the FRP steel bar 5 between the precast stop-type concrete top slab 3 and the original low-strength concrete slab 4, and at the same time open grouting holes 7 on the original low-strength concrete slab 4.

[0050] S6: Inject flowing mortar 6 through the reserved grouting hole 7, and cure for a period of time until the flowing mortar 6 reaches the predetermined strength, thus completing the reinforcement.

[0051] It is worth mentioning that the selection of precast slabs should be based on the actual situation. When there are walls in the structure to be reinforced, vertical slabs should be used, while when there are beams, precast L-shaped slabs with precast stop joints should be used. An appropriate number of FRP reinforcement bars 5 should be provided at the bottom of the beams. Furthermore, a certain gap should be reserved between the vertical slab or the precast L-shaped slab with precast stop joints 4 to accommodate the precast concrete top slab with precast stop joints 3 and grouting. The above description is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for reinforcing low-strength concrete building structures, characterized in that: The low-strength concrete building includes original low-strength concrete beams (2) and original low-strength concrete slabs (4). There are two original low-strength concrete beams (2), which are located on both sides of the bottom of the original low-strength concrete slab (4). Precast L-shaped plates (1) with precast stop openings are provided on the inner sides of the two original low-strength concrete beams (2). The two inner walls of the precast L-shaped plates (1) correspond to the bottom and inner walls of the original low-strength concrete beams (2), respectively. A gap is left between the precast L-shaped plates (1) and the original low-strength concrete beams (2). A precast concrete top plate (3) is erected on the top of the two precast L-shaped plates (1). A gap is left between the precast concrete top plate (3) and the original low-strength concrete slab (4). The gap is filled with flowing mortar (6). The precast stop-type concrete top slab (3) is composed of two "L"-shaped basic components and several "Z"-shaped basic components spliced ​​together. The upper half of one end of the "Z"-shaped basic component protrudes by one section, and the lower half of the other end protrudes by one section to form an interlocking part. Adjacent "Z"-shaped basic components interlock and are fixed to each other. The "L"-shaped basic components and the "Z"-shaped basic components at both ends interlock and are fixed to each other. The two sides of the precast stop-type concrete top slab (3) abut against the inner sidewalls of the original low-strength concrete beams (2) on both sides. Bolt holes are provided on the bottom and sides of the precast L-shaped plate (1) and the original low-strength concrete beam (2). Bolt holes are vertically provided on the precast L-shaped plate (3) and the original low-strength concrete plate (4). The precast L-shaped plate (1) and the original low-strength concrete beam (2), the precast L-shaped plate (3) and the original low-strength concrete plate (4) are fixed by bolts (8) passing through the preset bolt holes. FRP steel bars (5) are placed along the overall length of the gap; The precast L-shaped slab (1) and the precast concrete roof slab (3) are made of high-strength concrete and wire mesh.

2. The reinforced low-strength concrete building structure as described in claim 1, characterized in that: The flowing mortar (6) includes grout, water, sand, acrylic polymer emulsion, and microbial remediation agent, wherein the microbial remediation agent is an additive with Bacillus as the main component.

3. A method for reinforcing low-strength concrete buildings, characterized in that, Includes the following steps: S1: Bolt holes are vertically installed at the corresponding positions of the precast stop-type concrete top slab (3) and the original low-strength concrete slab (4), and bolt holes are drilled at the bottom and sides of the precast stop-type L-shaped slab (1) and the original low-strength concrete beam (2). S2: Install the prefabricated L-shaped plate (1) on the side of the original low-strength concrete beam (2). The two inner walls of the prefabricated L-shaped plate (1) correspond to the bottom and inner wall of the original low-strength concrete beam (2) respectively. There is a gap between the prefabricated L-shaped plate (1) and the original low-strength concrete beam (2), and the bolts (8) are fixed through the pre-set bolt holes. At the same time, the top of the prefabricated L-shaped plate (1) and the bottom of the original low-strength concrete plate (4) are kept at a suitable distance. S3: Place FRP steel bars (5) in the gap between the bottom of the original low-strength concrete beam (2) and the precast L-shaped plate (1), and pour flowing mortar (6) downward from the top of the inner wall of the original low-strength concrete beam (2) so that the flowing mortar (6) fills the gap between the precast L-shaped plate (1) and the original low-strength concrete beam (2) until the flowing mortar (6) reaches the expected strength. S4: A precast concrete top plate (3) is erected on the top of the precast L-shaped plate (1). A gap is left between the precast concrete top plate (3) and the original low-strength concrete plate (4). The precast concrete top plate (3) and the original low-strength concrete plate (4) are fixed by bolts (8) passing through the pre-set bolt holes. S5: Place the FRP steel bar (5) between the precast stop-type concrete top slab (3) and the original low-strength concrete slab (4), and at the same time open grouting holes (7) on the original low-strength concrete slab (4). S6: Inject flowing mortar (6) through the reserved grouting hole (7), and cure for a period of time until the flowing mortar (6) reaches the predetermined strength, that is, the reinforcement is completed.

4. The method for reinforcing low-strength concrete buildings as described in claim 3, characterized in that, In step S4: the two ends of the precast concrete top slab (3) are tightly attached to the inner wall of the original low-strength concrete slab (4).

5. The method for reinforcing low-strength concrete buildings as described in claim 3, characterized in that: The flowing mortar (6) includes grout, water, sand, acrylic polymer emulsion, and microbial remediation agent, wherein the microbial remediation agent is an additive with Bacillus as the main component.

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