CN116498113B - Waterproof structure of new and old concrete joint and construction method thereof - Google Patents

Abstract

This application relates to the field of concrete technology and specifically discloses a waterproof structure for the joint between new and old concrete and a construction method thereof. The structure comprises a new concrete block connected to an old concrete block, wherein the side end of the connection surface of the old concrete block is provided with a plurality of connection holes, and the inner wall of the connection hole is provided with a strip groove, and the distance between the side wall of the strip groove and the axis of the connection hole gradually decreases from the closed end to the open end. The new concrete block is pre-embedded with dowel bars that can be inserted into the connection holes, and the connection holes are poured with bonding mortar. This application achieves a stable connection, good waterproofing effect, and convenient construction.

Description

Waterproof structure of new and old concrete joint and construction method thereof

Technical Field

The application relates to the technical field of concrete, in particular to a waterproof structure at a joint of new and old concrete and a construction method thereof.

Background

In the construction design, the reconstruction of old concrete construction is often involved, and the newly poured concrete is formed into two separated bodies after hardening due to the fact that the setting and hardening time of the newly poured concrete is not synchronous with that of the old concrete, and the newly poured concrete is bonded only by the wall surfaces, which are in contact with each other, of the old concrete.

Therefore, the fusion performance between the concrete of the follow-up construction and the concrete of the prior construction is insufficient, the integration is poor, a gap is finally formed at the joint of the follow-up construction and the concrete, water flow is easy to infiltrate from the joint of the new concrete and the old concrete, and the strength of the joint of the follow-up construction and the concrete is further reduced after the water flow infiltrates from the gap.

Therefore, it is necessary to provide a waterproof structure which is convenient for the joint of new concrete and old concrete, enhances the waterproof performance of the joint of the new concrete and the old concrete and improves the overall strength of the new concrete and the old concrete after pouring.

Disclosure of Invention

In order to solve the problems of poor waterproof performance and low connection strength of the joint of the new concrete and the old concrete, the application provides a waterproof structure of the joint of the new concrete and the old concrete and a construction method thereof.

In a first aspect of the present application, the present application provides a construction method of a waterproof structure at a joint between old and new concrete, the construction method comprising the steps of:

S1, processing an old concrete block, namely perforating a connecting surface of the old concrete block, and roughening the inner wall of the perforated hole and the inner wall of the connecting surface;

s2, performing pouring pretreatment on the new concrete blocks, namely forming a new concrete precast area on the side branch template of the connecting surface, inserting dowel bars into holes formed in the old concrete blocks, and fixing;

S3, grouting, namely injecting bonding mortar into the holes formed in the step S1, and pouring the concrete prepared by using the bonding mortar into a new concrete pre-pouring area;

wherein the concrete is prepared from bonding mortar, stones and water according to the mass ratio of 1:0.25:0.3.

S4, caulking, namely curing to form a new concrete block, removing the template, and plugging a gap between the new concrete block and the old concrete block to form a waterproof structure at the joint of the new concrete block and the old concrete block.

Optionally, the step S1 further includes the steps of:

S11, perforating, namely perforating a plurality of connecting holes on the connecting surface of the old concrete block;

S12, grooving, namely obliquely forming a plurality of strip-shaped grooves along the axial direction of the connecting hole, wherein the side walls of the strip-shaped grooves are gradually opened by expanding outwards from the opening of the connecting hole to the closed end part of the connecting hole;

S13, chiseling the notch, namely chiseling the notch of the old concrete block, forming notches at the top and the bottom of the old concrete block, and chiseling the bottom wall of the notch, the connecting surface of the old concrete block and the inner wall of the connecting hole.

S2 further comprises the following steps:

S21, supporting a template, forming a new concrete precast zone on the side supporting template of the connecting surface, binding and fixing the dowel bars at the positions corresponding to the connecting holes, and inserting the end parts of the dowel bars into the connecting holes;

S22, reserving a notch in the template, reserving the notch in a new concrete precast zone through the template, and pre-fixing angle steel at the notch 5, wherein the angle steel is vertically staggered with the connecting surface;

S4 further comprises the steps of:

s41, curing, removing the mold, and correspondingly removing the mold plate and the angle steel after curing for 28 days to form a new concrete block 2;

S42, sticking waterproof coiled materials on the side wall of the notch, and respectively nailing the water stop strips into the new concrete block and the old concrete block by using cement nails;

S43, capping the waterproof layer, pouring waterproof mortar into the notch, trowelling to form the waterproof layer, and curing for 7 days to form the waterproof structure at the joint of the new concrete and the old concrete.

By adopting the construction method, the bonding area of the bonding mortar can be increased by forming the strip-shaped groove in the connecting hole, so that the bonding of the new concrete and the old concrete is stable, the dowel bars are arranged between the new concrete block and the old concrete block, so that the shearing force resistance of the new concrete block and the old concrete block after the new concrete block and the old concrete block are fixedly connected is greatly improved, and the whole process flow is simple and convenient to operate and easy to construct.

Optionally, in the step S3, the adhesive mortar includes the following components in parts by weight:

710-870 parts of dry material,

61.2-104 Parts of auxiliary agent,

125 Parts of active agent,

149.5-182 Parts of water.

Optionally, the dry material consists of (230-280)/(50-55)/(180-230)/(250-300) by weight ratio of silicate cement, graded quartz powder, medium sand and fine sand.

By adopting the technical scheme, the graded quartz powder is naturally weathered, has stable chemical properties, has excellent thermal stability due to almost zero thermal expansion rate, and can lead the cement to have wider performance and increase impermeability and compressive strength after being added with other dry materials.

Optionally, the auxiliary agent consists of (0.1-0.5)/(60-100)/(1-3) by weight ratio of defoamer, water reducer, fly ash and water-proofing agent.

The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether, the water reducing agent is selected from any one of lignosulfonate and naphthalene sulfonate formaldehyde polymer, the fly ash is ground fly ash with an activity index of more than 65%, and the waterproof agent is hydroxyl silicone oil.

By adopting the technical scheme, the water reducer can improve the workability and the viscosity of the bonding mortar, the waterproof agent increases the impermeability of the mortar, and the fly ash contains a large amount of pozzolanic active substances which can generate chemical reaction when being doped into the bonding mortar, so that the gel substance is generated, and the strength of the mortar is improved. The fly ash can play roles in rolling and densification in stirring mortar to reduce the water consumption of the mortar, enhance the structural strength after hardening and improve the stirring efficiency of the mortar, thereby achieving the effects of improving the crack resistance, the permeability resistance and the later strength.

Optionally, the active agent consists of lime paste, starch ether and metakaolin in a weight ratio of (15-30): (35-60): (50-60).

The starch ether is selected from one of potato starch, tapioca starch, corn starch and wheat starch, preferably potato starch.

By adopting the technical scheme, the starch ether can thicken the bonding mortar, increase sag resistance, sagging resistance and rheological property of the bonding mortar, and can be uniformly dispersed in a cement mortar system after being dissolved in water, and as the starch ether molecules are in a net structure and are negatively charged, positively charged cement particles can be adsorbed and can be used as a transitional bridge to connect cement, so that the slurry is endowed with a larger yield value, and the effect of improving sagging resistance or slip resistance is achieved; after being compounded with lime paste and metakaolin according to the proportion, the adhesive has good water-retaining thickening effect and improves bonding strength.

Optionally, the fiber-reinforced red mud fiber composite material further comprises an additive, wherein the additive is at least one selected from red mud and palm fiber.

Optionally, the additive consists of red mud and palm fiber in a weight ratio of (0.9-1.1): 1, preferably 1:1.

By adopting the technical scheme, the palm fiber has the advantages of low cost, recoverability, degradability, regeneration and the like, the red mud can change the surface affinity of the palm fiber, the uniformly distributed red mud and the palm fiber form a net-shaped supporting system in the bonding mortar, the internal layering, bleeding and cavity generation of the mortar are effectively reduced, aggregate sedimentation cracks are also reduced, a bridging effect is formed on each part of the mortar, and partial shrinkage internal stress in the mortar can be dispersed and counteracted, so that the generation of microcracks is inhibited.

In a second aspect of the present application, the present application provides a waterproof structure for a joint between old and new concrete, which adopts the following technical scheme:

The waterproof structure of the seam between old and new concrete comprises a new concrete block connected beside the old concrete block, wherein a plurality of connecting holes are formed in the side end of the connecting surface of the old concrete block, a strip-shaped groove is formed in the inner wall of each connecting hole, and the distance from the side wall of each strip-shaped groove to the axis of each connecting hole is gradually reduced from the closed end to the open end of each connecting hole;

The novel concrete block is embedded with the dowel bars which can be inserted into the connecting holes, bonding mortar is poured into the connecting holes, and the novel concrete block is prepared by pouring the bonding mortar and the stone blocks.

Through adopting above-mentioned technical scheme, after bonding mortar solidifies and maintenance shaping, can adhere mutually with the lateral wall of connecting hole and bar groove, with dowel cladding in the connecting hole for the intensity of new, old concrete layer connection increases, and the area of connection increases, and waterproof performance promotes.

Optionally, a new concrete precast area is reserved on one side of the connecting surface of the old concrete block before the new concrete block is poured, and notches are formed in the top and bottom of the old concrete block and the top and bottom of the new concrete precast area;

waterproof coiled materials are fixedly connected to the bottom wall of the notch, water stop strips are arranged at the two ends of the waterproof coiled materials corresponding to the notch, and a waterproof layer is poured on the top wall of the waterproof coiled materials in the notch

By adopting the technical scheme, when a new concrete layer is poured, the angle steel can seal the gap between the connection position of the new concrete and the old concrete, so that the concrete and the mortar are not easy to leak from the connection position of the new concrete and the old concrete in the pouring process, in addition, the water stop strip and the waterproof coiled material can shield the connection position of the new concrete and the old concrete, so that water flow is difficult to infiltrate from the connection position of the new concrete and the old concrete, and the anti-seepage effect of the connection position of the new concrete and the old concrete is enhanced.

In summary, the present application includes at least one of the following beneficial technical effects:

1. After the bonding mortar is solidified and cured and molded, the bonding mortar can be bonded with the side walls of the connecting holes and the strip-shaped grooves, and the dowel bars are coated in the connecting holes, so that the strength of the connection between the new concrete layer and the old concrete layer is increased, the connection area is increased, and the waterproof performance is improved;

2. the starch ether can thicken the bonding mortar, increase sagging resistance, sagging resistance and rheological property of the bonding mortar, and can better keep water and thicken effect and improve bonding strength after being compounded with lime paste and metakaolin according to the proportion;

3. The uniformly distributed red mud and palm fiber form a net-shaped supporting system in the new mixed mortar, so that the internal layering, bleeding and cavity generation of the mortar are effectively reduced, aggregate settlement cracks are also reduced, a bridging effect is formed on each part of the mortar, and partial shrinkage internal stress in the mortar can be dispersed and counteracted, so that the generation of microcracks is inhibited.

Drawings

Fig. 1 is a construction flow chart of a waterproof structure in embodiment 1 of the present application.

Fig. 2 is an elevation view of the joint face of the old concrete block in an embodiment of the application.

Fig. 3 is a schematic diagram of a position structure for setting a new concrete precast zone and fixing angle steel in the construction process according to the embodiment of the application.

Fig. 4 is a schematic cross-sectional view of a waterproof structure in an embodiment of the present application.

The concrete block is characterized by comprising the following components of 1, an old concrete block, 11, a connecting surface, 2, a new concrete block, 21, dowel bars, 22, a template, 23, a new concrete precast area, 3, a connecting hole, 31, a strip groove, 4, bonding mortar, 5, a notch, 6, angle steel, 7, a waterproof coiled material, 71, a water stop bar, 72, a cement nail and 8 and a waterproof layer.

Detailed Description

The application is described in further detail below with reference to fig. 1-4.

Example 1

Referring to fig. 1, the construction method of the waterproof structure at the joint of the old and new concrete in the embodiment of the application comprises the following steps:

s1, processing an old concrete block 1, namely perforating a connecting surface 11 of the old concrete block 1, and roughening the inner wall of the perforating and the side wall of the connecting surface 11;

s2, carrying out pouring pretreatment on the new concrete block 2, namely, branching a template 22 on the connecting surface 11 to form a new concrete precast zone 23, inserting the dowel bars 21 into holes formed in the old concrete block 1 and fixing the dowel bars;

s3, grouting, namely injecting bonding mortar 4 into the hole formed in the step S1, and pouring the concrete prepared by using the bonding mortar 4 into a new concrete precast area 23;

s4, caulking, namely curing to form a new concrete block 2, removing the template 22, and plugging the gap between the new concrete block 2 and the old concrete block 1 to form a waterproof structure at the joint of the new concrete block and the old concrete block.

Specifically, S1 further includes the following steps:

S11, perforating, namely forming a plurality of connecting holes 3 on the connecting surface 11 of the old concrete block 1;

s12, grooving, namely obliquely forming a plurality of strip-shaped grooves 31 along the axial direction of the connecting hole 3, wherein the side walls of the strip-shaped grooves 31 are gradually outwards expanded from the opening of the connecting hole 3 to the closed end part of the connecting hole;

s13, chiseling the notch 5, namely, forming the notch 5 at the top and the bottom of the old concrete, and chiseling the bottom wall of the notch 5, the connecting surface 11 of the old concrete block 1 and the inner wall of the connecting hole 3.

S2 further comprises the following steps:

s21, supporting the templates 22, namely forming a new concrete precast zone 23 on the side supporting templates 22 of the connecting surface 11, and binding and fixing the dowel bars 21 at the positions corresponding to the connecting holes 3, wherein the end parts of the dowel bars 21 are inserted into the connecting holes 3;

s22, reserving a notch 5 in a template 22, namely reserving the notch 5 in a new concrete precast zone 23 through the template 22, and pre-fixing angle steel 6 at the notch 5, wherein the angle steel 6 is vertically staggered with the connecting surface 11;

S4 further comprises the steps of:

s41, curing and demolding, namely correspondingly removing the template 22 and the angle steel 6 after curing for 28 days to form a new concrete block 2;

s42, sealing the notch 5, namely adhering a waterproof coiled material 7 to the side wall of the notch 5, and respectively nailing the water stop strips 71 into the new concrete block 2 and the old concrete block 1 by using cement nails 72;

s43, capping the waterproof layer 8, namely pouring waterproof mortar into the notch 5, trowelling to form the waterproof layer 8, and curing for 7 days to form the waterproof structure at the joint of the new concrete and the old concrete.

The construction method of the waterproof structure at the joint of the new concrete and the old concrete in the embodiment 1 is implemented by arranging a strip-shaped groove in a connecting hole, so that the bonding area of bonding mortar can be increased, the bonding of the new concrete and the old concrete is stable after the molding, the pulling resistance and the tensile resistance are improved, a dowel bar is arranged between the new concrete block and the old concrete block, so that the shearing resistance is greatly improved after the new concrete block and the old concrete block are fixedly connected, and the whole process flow is simple and convenient to operate and easy to construct.

Example 2

The embodiment 2 of the application discloses a waterproof structure at a joint of new and old concrete. Referring to fig. 2 and 3, a waterproof structure for a joint between old and new concrete comprises a new concrete block 2 connected beside an old concrete block 1, a plurality of connecting holes 3 are formed in the side end of a connecting surface 11 of the old concrete block 1, a strip-shaped groove 31 is formed in the inner wall of the connecting hole 3, and the distance from the side wall of the strip-shaped groove 31 to the axis of the connecting hole 3 is gradually reduced from the closed end to the open end of the strip-shaped groove 31.

The new concrete block 2 is pre-embedded with a dowel bar 21 which can be inserted into the connecting hole 3, the connecting hole 3 is internally poured with bonding mortar 4, and the new concrete block 2 is prepared by pouring the bonding mortar 4 and stone blocks.

Referring to fig. 3 and 4, notches 5 are formed at the top wall and the bottom wall of the old concrete block 1 and the new concrete block 2, before new concrete is poured, a new concrete pre-pouring area 23 is formed by fixing and dividing a template 22, angle steel 6 for blocking gaps between two adjacent notches 5 is installed in the notches 5 in a butt joint mode, a plastic film or other easily-torn shielding films can be arranged at the positions, where the angle steel 6 is attached to concrete, of the two corresponding angle steel 6 positions at the top wall and the bottom wall of the new/old concrete block, screw drawknots are arranged, the angle steel 6 is fixed, and meanwhile, a support is arranged between the two opposite angle steel 6 to further fix and limit the angle steel 6.

After the new concrete is poured and formed and cured until the strength reaches the standard to form a new concrete block 2, a waterproof roll 7 is fixedly connected to the bottom wall of the notch 5, water stop strips 71 are arranged at two ends of the waterproof roll 7 corresponding to the notch 5, a waterproof layer 8 is poured on the top wall of the waterproof roll 7, the waterproof layer 8 can be formed by pouring adhesive mortar 4, and other waterproof mortar can be used for pouring and curing.

According to the waterproof structure for the joint between the new concrete and the old concrete, in the embodiment 2, as the strip-shaped groove 31 is formed, the radial dimension of the connecting hole 3 from the bottom end close to the hole to the opening end is gradually reduced, after the bonding mortar 4 is filled, the bonding mortar 4 coats the dowel bars 21, so that the area 11 of the connecting surface of the dowel bars with the connecting hole 3 is increased, the bonding mortar 4 is cured and hardened to form, the outer wall of the waterproof layer is firmly adhered with the inner wall of the connecting hole 3, loosening is difficult to occur, and the bonding mortar 4 layer, the waterproof coiled material 7 and the water stop strip 71 arranged at the upper part of the notch 5 enable water flow to be further difficult to penetrate, so that the bonding performance and the impervious effect of the joint between the new concrete block 2 and the old concrete block 1 are improved.

Examples 3 to 7

Examples 3-7 each provide a paste mortar.

The following example selects Portland cement as 32.5-grade composite Portland cement sold in the market, and quartz powder is quartz powder with fineness of 120-200 meshes;

the defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether;

the water reducing agent is sodium lignin sulfonate;

The waterproof agent is hydroxyl silicone oil;

The starch ether is potato starch;

The metakaolin is 1250 mesh metakaolin with water content lower than 5% produced by Shanxi Kagaku Feng Gaoling;

The fly ash is ground fly ash with the activity index of more than 65%;

The active agent in examples 3-7 consisted of lime paste, starch ether and metakaolin in a weight ratio of 21:49:55.

The preparation method of the adhesive mortar in examples 3-7 comprises the following steps:

s1, adding fly ash, a defoaming agent, a water reducing agent, a waterproof agent and water into a reaction container, and uniformly stirring to obtain an auxiliary agent solution;

S2, adding graded quartz powder, medium sand and fine sand into a stirring container, adding silicate cement and water, and uniformly stirring;

S3, adding the auxiliary agent solution obtained in the step S1 into a stirring container, adding the active agent and uniformly stirring.

The difference between the above examples is that the parts by weight of the components in the paste mortar are shown in Table 1.

Table 1 examples 3 to 7 provide paste mortars having parts by weight of each component

Examples 8 to 9

Examples 8-9 provide a paste mortar, respectively.

The above examples differ from example 3 in the weight ratio of the components of the active agent in the paste mortar, as shown in Table 2.

TABLE 2 addition amount of each component of the active agent in the paste mortar provided in example 3 and examples 8 to 9

Examples 10 to 12

Examples 10-12 each provide a paste mortar.

The above examples differ from example 3 in that the adhesive mortar was further added with additives, as shown in Table 3.

The method for preparing the paste mortar in examples 10 to 12, referring to fig. 1, comprises the steps of:

s1, adding fly ash, a defoaming agent, a water reducing agent, a waterproof agent and water into a reaction container, and uniformly stirring to obtain an auxiliary agent solution;

s2, adding graded quartz powder, medium sand and fine sand into a stirring container, adding silicate cement, adding additives and water, and uniformly stirring;

S3, adding the auxiliary agent solution obtained in the step S1 into a stirring container, adding the active agent and uniformly stirring.

TABLE 3 additive amount of the additive in the paste mortar provided in example 3 and examples 10 to 12

Example 13

Example 13 provides a paste mortar.

The difference between the above examples and example 3 is that in example 13, the active agent comprises lime paste, starch ether and metakaolin in a mass ratio of 10:35:45.

Example 14

Example 14 provides a paste mortar.

The above-described examples differ from example 3 in that in example 14 the waterproofing agent was replaced by a melamine-formaldehyde resin with a hydroxy silicone oil.

Example 15

Example 15 provides a paste mortar.

The above example differs from example 3 in that the fly ash is replaced by calcium oxide.

Performance detection

Test Standard JC/T984-2011 Polymer Cement waterproof mortar industry Standard

GB23440-2009 national standard inorganic Water-proof leakage-stopping Material

The test aims to detect the impervious pressure, the adhesive strength and other mechanical property test conditions of the adhesive mortar, namely, the test room test and dry curing conditions, namely, the temperature (23+/-2) DEG C, the relative humidity (50+/-10)%, and the curing room (box) curing conditions, namely, the temperature (20+/-3) DEG C, the relative humidity is more than or equal to 90%. And maintaining the water pool at 20+/-2 deg.c.

The test steps are as follows:

1. Proportioning materials

The experiment is carried out according to the mixing ratio of the embodiments, a planetary cement mortar stirrer is adopted, stirring is carried out at low speed, and stirring is carried out for 3min each time, and the stirring is carried out for 1-3 min.

2. After the anti-seepage test mould is filled once after the anti-seepage test mould is evenly carried out, and (5) vibrating and forming on a vibrating table, and vibrating for 2min. The test was carried out as described in GB 23440-2009 at 6.5.2.

3. Anti-permeation pressure test

And (3) curing the test pieces until the test pieces are cured to the age of 7d, and testing according to 6.5.1.2,6.5.1.4 in GB 23440-2009, wherein the maximum pressure value of four non-seepage test pieces in each group of six test pieces is used as the seepage resistance pressure of the test pieces.

4. Bond strength test

A concrete slab conforming to the specification of 6.3 and a tensile bond strength molding frame conforming to the specification of 6.4.5 in JC/T985-2011 are adopted. The concrete slab was immersed in water for 24 hours under the condition of 6.1.3 and taken out, and after the surface water stain was wiped off, the concrete slab was tested according to JC/T985-2005 at 6.8.

5. Other mechanical property tests are carried out according to JC/T984-2011.

The mechanical properties of the adhesive mortar in example 3 were tested as follows:

Table 4 mechanical properties of the paste mortar in example 3

TABLE 5 mechanical Properties of the paste mortar in example 12

According to the test results of example 3 in Table 4, after lime paste, starch ether and metakaolin in the active agent are added according to the above proportion, the 7d impervious pressure is up to 1.65Mpa, the 28d impervious pressure is increased to 1.99Mpa, the lifting rate is 20.61%, the 7d adhesive strength is 1.32Mpa, the 28d adhesive strength is increased to 20.61Mpa, the lifting rate is 32.58%, the change of the impervious pressure and the lifting rate of the adhesive strength is obvious, and all the mechanical properties of the adhesive mortar are up to standard and are qualified, and the adhesive mortar has excellent impervious and adhesive effects.

According to the test results of example 12 in Table 5, after 42 parts by mass of red mud and palm fiber are added in a ratio of 1:1, the mechanical properties such as flexibility and the like of the adhesive mortar are improved, the water absorption rate, the shrinkage rate and the like are reduced, the anti-seepage pressure and the adhesive strength are obviously increased, the anti-seepage pressure and the adhesive strength are respectively 1.74Mpa, 1.41Mpa and 28d and are increased to 2.48Mpa and 2.11Mpa, and the improvement rates are 42.53% and 49.65%.

The red mud and the palm fibers which are uniformly distributed form a net-shaped bearing system in the bonding mortar after the additive is added, the red mud assists the palm fibers to strengthen the bonding performance and the bearing strength, the internal layering, bleeding and cavity generation of the mortar are effectively reduced, aggregate sedimentation cracks are also reduced, meanwhile, the hydroxyl silicone oil and the additive are combined to have strong adhesive force, and the two further improve the seepage prevention, the compression resistance and the bonding performance of the bonding mortar together.

The test results of the impermeability pressure and the adhesive strength of the paste mortar 7d of examples 3 to 12 and 13 to 3 are shown in Table 6 below, and the test object is the impermeability pressure of the 6mm mortar test piece:

table 67d test results of permeation resistance and adhesive strength

	Impervious pressure/MPa (7 d)	Bond strength/MPa (7 d)
			Example 3	1.65	1.32
Example 4	1.46	1.2
			Example 5	1.47	1.17
Example 6	1.37	1.14
			Example 7	1.32	1.12
Example 8	1.47	1.31
			Example 9	1.59	1.33
Example 10	1.69	1.35
			Example 11	1.71	1.36
Example 12	1.74	1.41
			Example 13	1.27	1.16
Example 14	1.29	1.01
			Example 15	1.61	1.11

The test results of the anti-permeation pressure and the adhesive strength of the adhesive mortar 28d in examples 3 to 15 are shown in the following Table 7, and the test object is a 6mm adhesive mortar test piece:

Table 728d shows the results of the permeation resistance and bond strength test

From the test results of Table 7, the test results of comparative examples 3 and 2 to 3 show that the adhesive strength of the adhesive mortar is affected when the addition ratio of Portland cement, graded quartz powder, middlings and fine sand in the dry material is changed, but the mechanical properties required by JC/T985-2011 can be satisfied, because cement can bond the quartz powder, middlings and fine sand tightly with each other as an adhesive material, but when the addition ratio is excessive, the compressive strength of the adhesive mortar is lowered.

As can be seen from the detection results of comparative examples 3 and 6-7, the contents of the components of the auxiliary agent are changed, the anti-seepage pressure and the bonding strength of the bonding mortar are also influenced, when the mass parts of the defoamer, namely the water reducing agent, namely the fly ash and the water proofing agent are (0.1-0.5), the mass parts of the defoamer, namely the water proofing agent are (0.1-0.5), the mass parts of the defoamer are (60-100), the mass parts of the defoamer are (1-3), the anti-seepage pressure and the bonding strength of the bonding mortar are both above the qualified ranges, the anti-seepage strength increasing rate of the bonding mortar 7d-28d can reach 13.87% -20.61%, the bonding strength increasing rate can reach 27.19% -32.58%, and when the mass parts of the defoamer, namely the water reducing agent, namely the fly ash and the water proofing agent, are 0.2:0.3:80:2, the anti-seepage strength increasing rate and the bonding strength increasing rate are the highest.

As can be seen from the detection results of comparative examples 3 and 8-9, when the content of each component in the active agent is changed, and the lime paste, namely the starch ether, namely the metakaolin is changed from (15-30) to (35-60) to (50-60), the impervious pressure and the bonding strength of the bonding mortar are reduced compared with those of example 3, but still can be qualified, wherein after the relative content of the starch ether is increased, the impervious pressure of 7d/28d and the bonding strength of 7d/28d are improved, and the adhesive mortar can be thickened due to the starch ether, so that the sagging resistance, sagging resistance and rheological property of the bonding mortar are improved, and after the lime paste and the metakaolin are compounded according to the proportion, the water retention thickening effect can be better, and the bonding strength is improved.

As shown by the detection results of comparative examples 3 and 10-12, after the additive is added, the anti-seepage pressure and the bonding strength of the bonding mortar are obviously improved, when 42 parts of red mud are independently added, the 7d anti-seepage pressure is 1.69Mpa, the 28d anti-seepage pressure is increased to 2.15Mpa, the lifting rate is 27.22%, the 7d bonding strength is 1.35Mpa, the 28d bonding strength is increased to 1.83Mpa, the lifting rate is 35.56%, and when 42 parts of palm fiber are independently added, the anti-seepage pressure and the lifting rate of the bonding strength of the bonding mortar are also obviously improved.

However, when 42 parts by weight of the additive is added to the red mud and the palm fiber according to the proportion of 1:1, the 7d/28d impervious pressure and the 7d/28d impervious pressure of the adhesive mortar reach the highest, the improvement rate of the impervious strength of 7d to 28d reaches 42.53 percent, the improvement rate of the adhesive strength reaches 49.65 percent, and the mortar performance can be obviously improved after the red mud and the palm fiber are mixed and added.

As is clear from the test results of comparative examples 3 and 13, when the weight ratio of lime paste, starch ether and metakaolin is changed to 10:35:45, the anti-seepage pressure and the bonding strength of the bonding mortar are reduced, and the anti-seepage pressure and the bonding strength of 7d/28d are still acceptable, but the bonding strength of 7d of the bonding mortar is only 1.27Mpa, and the bonding strength improvement rate is lower than 10%.

The test results of comparative examples 3 and 14 show that when the waterproof agent is replaced by melamine-formaldehyde resin, the performance can still meet the JC/T985-2011 requirement and the anti-seepage strength improvement rate reaches 17.05, but the 7d bonding strength and the 28d bonding strength of the bonding mortar are obviously reduced, and the bonding strength improvement rate is as low as 7.92%.

As is clear from the test results of comparative examples 3 and 15, when the fly ash is replaced with calcium oxide, the anti-permeability performance of the adhesive mortar is reduced but not remarkable, the adhesive strength of the adhesive mortar is reduced, and the anti-permeability strength improvement rate and the adhesive strength improvement rate of 7 to 28d are respectively reduced to 7.45% and 8.11%, which are probably because the active ingredients in the fly ash can improve the workability of concrete mixture, and the pumpability of the concrete is enhanced, so that the hardness of the adhesive mortar after post hardening is higher.

The above embodiments are not intended to limit the scope of the application, so that the equivalent changes of the structure, shape and principle of the application are covered by the scope of the application.

Claims (7)

1. The construction method of the waterproof structure at the joint of the new concrete and the old concrete is characterized by comprising the following steps of:

S1, processing an old concrete block (1), namely perforating a connecting surface (11) of the old concrete block (1), and roughening the inner wall of the perforating and the side wall of the connecting surface (11);

s2, carrying out pouring pretreatment on the new concrete block (2), namely forming a new concrete precast zone (23) by branching a template (22) on a connecting surface (11), and inserting and fixing the dowel bars (21) in holes formed in the old concrete block (1);

S3, grouting, namely injecting the bonding mortar (4) into the hole formed in the step S1, and pouring the concrete prepared by using the bonding mortar (4) into a new concrete pre-pouring area (23);

S4, caulking, namely curing to form a new concrete block (2), removing the template (22), and plugging a gap between the new concrete block (2) and the old concrete block (1) to form a waterproof structure at the joint of the new concrete block and the old concrete block;

In the step S3, the bonding mortar comprises the following components, by weight, 710-870 parts of dry materials, 61.2-104 parts of auxiliary agents, 125 parts of active agents and 149.5-182 parts of water;

the additive is composed of red mud and palm fiber in a weight ratio of (0.9-1.1): 1.

2. The method for constructing a waterproof structure at a joint between old and new concrete according to claim 1, wherein the step S1 further comprises the steps of:

S11, perforating, namely perforating a plurality of connecting holes (3) on the connecting surface (11) of the old concrete block (1);

s12, grooving, namely obliquely arranging a plurality of strip-shaped grooves (31) along the axial direction of the connecting hole (3), wherein the side walls of the strip-shaped grooves (31) are gradually outwards expanded from the opening of the connecting hole (3) to the closed end part of the connecting hole;

s13, chiseling the notch (5), namely, forming the notch (5) at the top and the bottom of the old concrete, and chiseling the bottom wall of the notch (5), the connecting surface (11) of the old concrete block (1) and the inner wall of the connecting hole (3).

3. The construction method of the waterproof structure at the joint of new and old concrete according to claim 1, wherein the dry material consists of (230-280): (50-55): (180-230): (250-300) by weight of Portland cement, graded quartz powder, medium sand and fine sand.

4. The construction method of the waterproof structure at the joint of the new concrete and the old concrete according to claim 1, wherein the auxiliary agent consists of a defoaming agent, a water reducing agent, fly ash and a waterproof agent according to the weight ratio of (0.1-0.5): (0.1-0.5): (60-100): (1-3).

5. The construction method of the waterproof structure at the joint of the new concrete and the old concrete according to claim 3, wherein the active agent consists of lime paste, starch ether and metakaolin in a weight ratio of (15-30): (35-60): (50-60).

6. A waterproof structure prepared by the construction method according to any one of claims 1-5 is characterized by comprising a new concrete block (2) connected beside an old concrete block (1), wherein a plurality of connecting holes (3) are formed at the side end of a connecting surface (11) of the old concrete block (1), a strip-shaped groove (31) is formed in the inner wall of the connecting hole (3), and the distance from the side wall of the strip-shaped groove (31) to the axis of the connecting hole (3) is gradually reduced from the closed end to the open end of the strip-shaped groove;

the novel concrete block (2) is embedded with a dowel bar (21) which can be inserted into the connecting hole (3), bonding mortar (4) is poured into the connecting hole (3), and the novel concrete block (2) is prepared by pouring the bonding mortar (4) and stone blocks.

7. The waterproof structure obtained by the construction method for the waterproof structure at the joint of the old concrete and the new concrete according to claim 6 is characterized in that a new concrete pre-cast area (23) is reserved on one side of a connecting surface (11) of the old concrete block (1) before the new concrete block (2) is poured, and notches (5) are formed at the top and the bottom of the old concrete block (1) and the new concrete pre-cast area (23);

waterproof coiled material (7) is fixedly connected to the bottom wall of the notch (5), water stop strips (71) are arranged at two ends of the waterproof coiled material (7) corresponding to the notch (5), and a waterproof layer (8) is poured on the top wall of the waterproof coiled material (7) through the notch (5).