CN114319875A - Seamless construction process for super-large-area concrete ground - Google Patents
Seamless construction process for super-large-area concrete ground Download PDFInfo
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Abstract
The embodiment of the invention discloses a seamless construction process for a concrete floor with an oversized area, which belongs to the technical field of concrete construction processes and comprises cement, sand, stones, concrete admixture and fly ash, wherein expansion joints and post-pouring belts are not reserved in the seamless construction of the concrete floor, the concrete is poured in a whole structural plane in layers, the concrete poured in a first layer is not initially solidified when a second layer is poured after the first layer is poured, the concrete is poured layer by layer in such a way until the pouring is finished, the construction is carried out along a short edge and a long edge and is divided into two sections if necessary, the pouring is carried out from the middle to two ends or two ends to the middle, and the pouring thickness is not more than 50 CM. The problem that the concrete is easy to crack after being poured due to the large shrinkage, the poor ultimate tensile capacity and the uneven pouring surface of the concrete is solved. The method has the advantages of stricter and scientific construction process of concrete, prevention of cracks and ground collapse, and environmental protection.
Description
Technical Field
The embodiment of the invention relates to the technical field of concrete construction processes, in particular to a seamless construction process for a concrete floor with an ultra-large area.
Background
In recent years, along with the rapid development of economy in China, buildings with ultra-long and ultra-wide plane sizes are increasingly applied to the fields of large public buildings, industrial plants, commercial centers and the like. In view of the requirements of integrity, use function and construction period of buildings and structures, the ground or floor of the buildings mostly needs to be free of expansion joints and post-pouring belts, or the distance between the expansion joints exceeds the current standard requirement, namely, the requirement of seamless construction is provided for the concrete floor structure with the ultra-large area.
In the seamless construction of an oversized area concrete structure, the unstable integrity of concrete caused by the deformation and cracking of the concrete and the flatness of the ground before concrete pouring is also a main reason for crack formation, so that the reduction of the shrinkage and ultimate tensile strength of the concrete and the flatness of a pouring surface are the key for preventing the occurrence of cracks in the concrete, and a series of technical measures are required to be taken in each link of concrete pouring, the selection of materials, the experiment of concrete proportioning and the like.
Disclosure of Invention
Therefore, the embodiment of the invention provides a seamless construction process for a concrete ground with an oversized area, which aims to solve the problem that the concrete is easy to crack after being poured due to large shrinkage, poor ultimate tensile capacity and uneven pouring surface in the prior art.
In order to achieve the above object, the embodiments of the present invention provide the following technical solutions: a seamless construction process for a concrete floor with an ultra-large area comprises the following steps:
according to the first aspect of the embodiment of the invention, the concrete comprises cement, sand, stones, concrete admixture and fly ash, no expansion joint and post-pouring belt are reserved in the seamless construction of the concrete ground, the concrete is poured in layers on the whole structural plane, and when the first layer is poured and then the second layer is poured, the concrete poured on the first layer is not initially set, the step is carried out layer by layer until the pouring is finished, the construction is carried out along the short edge and the long edge, if necessary, the construction is carried out in two sections, the construction is carried out from the middle to two ends or two ends to the middle, and the pouring thickness is not more than 50CM, and the concrete comprises the following steps: a. performing cushion layer treatment, namely directly pouring and flattening concrete, wherein the thickness of a cushion layer of an expanded foundation is not less than 70mm, and the strength grade of the cushion layer concrete is not less than C10; b. the steel bars are checked, bound and installed, the steel bars are bound and installed by adopting double-layer bidirectional configuration, the anti-cracking structural steel bars are arranged by adopting stress and structural steel bars in a through manner, the reinforcement ratio of the temperature and shrinkage steel bars is not less than 0.10%, and the spacing is not more than 180 mm; c. installing a concrete template, and splicing and supporting the template by using a steel plate net, a die-removal-free wire netting or a small wood board; d. selecting raw materials of concrete, namely cement, aggregate and sand; e. optimizing the mixing proportion of concrete, wherein the water cement ratio of the concrete is 0.4-0.6, the sand rate is 39-45%, and the slump is 12-16 cm; f. hydration heat test, measuring the heat productivity of 3 days, 7 days, 14 days and 28 days, wherein the hydration heat of 7 days is not more than 250 kj/kg; g. performing on-site over-examination; h. approving pouring and vibrating, wherein the vibrating time of each point is 15-30 s, and secondary re-vibration is carried out after 20-25 min; i. and (3) temperature measurement maintenance, wherein temperature measurement is started when the concrete is poured into a mold, temperature measurement is carried out for 1 time every 2 hours, the lifting value and the temperature difference value of each temperature measurement point are recorded and calculated, data are fed back to a construction unit and a supervision unit in time, when the temperature difference between the inside and the outside of the concrete exceeds 22 ℃, whether a temperature measurement instrument breaks down or not is immediately checked, and when the temperature difference exceeds 25 ℃, field construction managers and related personnel are informed to take corresponding measures.
Further, the bedding course treatment comprises the step of using coarse-grained soil, and allowing a certain water changing buffer time for the soil layer below the bedding course.
Further, the raw material of the concrete is low-heat slag portland cement; selecting aggregates, namely selecting non-alkali active aggregates; the fine aggregate is medium sand, the content of particles passing through a sieve pore of 0.315mm is not less than 15%, the aggregate with large elastic modulus is adopted, the coarse aggregate is 6-30 mm in particle size, continuous gradation is adopted, the content of needle piece particles is not more than 10%, and the content of mud is not more than 1%.
Furthermore, the concrete is doped with high-quality fly ash and additives for crack resistance, seepage prevention, water reduction, slow setting and the like during the preparation of the concrete.
According to the second aspect of the embodiment of the invention, the inclined plane is layered, and the layered casting thickness of the concrete is estimated according to the slump of the concrete and the casting amount in the initial setting time of the concrete.
Furthermore, when the concrete formwork is installed, sundries such as garbage and soil in the formwork and oil stains on the steel bars are removed completely, and the cushion blocks of the steel bars are well cushioned.
Further, when the concrete is poured, the pouring gap time of the concrete between different pouring areas and between an upper layer and a lower layer does not exceed the initial setting time of the concrete.
Further, after mass concrete is poured in a certain amount according to a reference elevation surface, before the concrete is initially set, the surface of the mass concrete is stricken off by using an aluminum alloy long scraping rule, the wood crabs are stricken off for the first time, after water is collected, secondary plastering is carried out, water collecting cracks appear on the surface along the positions of the steel bars, the mass concrete is rolled for a plurality of times by using a roller, and the wood crabs are used for rubbing and closing the water collecting cracks.
Furthermore, in the process of vibrating the concrete, the vibrating rod needs to be slightly pulled up and down to realize fast insertion and slow pulling so as to vibrate uniformly up and down.
Further, concrete is maintained after pouring, watering maintenance is carried out, watering is carried out in winter at the noon in fine weather, watering is carried out immediately in other seasons, the heat insulation material is lifted and covered, the heat insulation material is removed for more than 10 days, the heat insulation material is gradually removed in batches in stages on the basis of real-time monitoring, the cooling speed is slowed down, the weather change is noticed, and heat insulation is enhanced before a cold tide comes.
Further, in the maintenance stage, the personnel have the following according to the day and night duty consideration: each technician is one for each class, and the maintainers arrange according to the workload.
The embodiment of the invention has the following advantages:
1. by designing the construction process, the concrete is more scientifically and strictly constructed by optimizing the proportion, selecting materials, carrying out a detailed hydration heat experiment, testing the initial setting time and detecting a slump test, the concrete is reduced from cracking after construction, the shrinkage of the concrete is reduced, the ultimate tensile capacity of the concrete is improved, the frost resistance of a base surface is enhanced, and the expansibility is reduced, so that the phenomena that the ground is easy to crack and collapse after the concrete is poured are reduced;
2. by designing the construction process, the whole construction process is more environment-friendly and energy-saving through strict requirements on the construction process and fine treatment of wastewater, and meanwhile, the influence of noise on the living environment of surrounding residents can be reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other implementation drawings can be derived from the drawings provided by those of ordinary skill in the art without any creative effort.
The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the effects and the achievable by the present invention, should still fall within the scope of the present invention.
FIG. 1 is a schematic flow diagram of the present invention;
Detailed Description
The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to the description and the attached drawing 1, the seamless construction process for the concrete floor with the ultra-large area comprises cement, sand, stones, a concrete additive and fly ash, wherein a telescopic seam and a post-pouring belt are not reserved in the seamless construction of the concrete floor, concrete is poured in a whole structural plane in a comprehensive layering mode, the first layer poured concrete is not initially set when a second layer is poured back after the first layer is poured, the steps are carried out layer by layer in such a way until the pouring is finished, the construction is carried out along a short edge and a long edge, the two steps are carried out if necessary, the pouring is carried out from the middle to two ends or two ends to the middle at the same time, the pouring thickness is not more than 50CM, and the process specifically comprises the following steps: a. performing cushion layer treatment, namely directly pouring and flatly filling concrete, wherein the thickness of the cushion layer of the extended foundation is not less than 70mm, and the strength grade of the cushion layer concrete is not less than C10; b. the steel bar is checked, bound and installed, the steel bar binding installation adopts double-layer bidirectional configuration, the anti-cracking structural steel bar adopts stress and structural steel bar through arrangement, the temperature and shrinkage steel bar reinforcement ratio is not less than 0.10%, and the spacing is not more than 180 mm; c. installing a concrete template, and splicing and supporting the template by using a steel plate net, a die-removal-free wire netting or a small wood board; d. selecting concrete raw materials, namely cement, aggregate and sand; e. optimizing the mixing proportion of concrete, wherein the water cement ratio of the concrete is 0.4-0.6, the sand rate is 39-45%, and the slump is 12-16 cm; f. hydration heat test, measuring the heat productivity of 3 days, 7 days, 14 days and 28 days, wherein the hydration heat of 7 days is not more than 250 kj/kg; g. performing on-site over-examination; h. approving pouring and vibrating, wherein the vibrating time of each point is 15-30 s, and secondary re-vibration is carried out after 20-25 min; i. and (3) temperature measurement and maintenance, wherein the temperature measurement is started when the concrete is poured into a mold, the temperature is measured for 1 time every 2 hours, the lifting value and the temperature difference value of each temperature measurement point are recorded and calculated, data are fed back to a construction unit and a supervision unit in time, when the temperature difference between the inside and the outside of the concrete exceeds 22 ℃, whether a temperature measurement instrument breaks down or not is immediately checked, and when the temperature difference exceeds 25 ℃, field construction managers and related personnel are informed to take corresponding measures.
The cushion course treatment comprises the steps of adopting coarse-grained soil and reserving certain water changing buffer time for a soil layer below the cushion course.
The raw material of the concrete is low-heat slag portland cement; selecting aggregates, namely selecting non-alkali active aggregates; the fine aggregate is medium sand, the content of particles passing through a sieve pore of 0.315mm is not less than 15%, the aggregate with large elastic modulus is adopted, the coarse aggregate is 6-30 mm in particle size, continuous grading is adopted, the content of needle piece particles is not more than 10%, and the content of mud is not more than 1%.
The concrete is doped with high-quality fly ash and additives for crack resistance, seepage prevention, water reduction, retardation and the like during the preparation.
When the concrete formwork is installed, sundries such as garbage and soil in the formwork and oil stains on the steel bars are cleaned, and the cushion blocks of the steel bars are well cushioned.
When concrete is poured, the pouring clearance time of the concrete between different pouring areas and between an upper layer and a lower layer is not more than the initial setting time of the concrete.
After mass concrete is poured in a certain amount according to a reference elevation surface, before the concrete is initially set, the surface of the mass concrete is stricken off by using an aluminum alloy long scraping rule, the mass concrete is stricken off by using wooden crabs, the mass concrete is firstly trowelled, after water is collected, secondary plastering is carried out, water collecting cracks appear on the surface along the positions of reinforcing steel bars, the mass concrete is rolled for a plurality of times by using a roller, the mass concrete is kneaded by using the wooden crabs, and the water collecting cracks are closed.
In the process of vibrating the concrete, the vibrating rod is slightly pulled up and down to vibrate uniformly up and down by 'inserting and pulling slowly'.
And (3) curing the concrete after pouring, watering for curing, watering in the winter at around noon in fine weather, immediately watering in other seasons, lifting the heat insulation material to cover, removing the heat insulation material for more than 10 days, gradually removing the heat insulation material in batches in stages on the basis of real-time monitoring, slowing down the cooling speed, paying attention to weather changes, and enhancing heat insulation before cold tides.
In the maintenance stage, the personnel have the following according to the day and night duty consideration: each technician is one for each class, and the maintainers arrange according to the workload.
The real-time scene is specifically as follows: a. the bed course is handled, and the concrete is directly pour and is filled up flatly, and the bed course thickness of extension basis is not less than 70mm, and bed course concrete intensity grade is not less than C10, can reach anti frost heaving's purpose, and its antagonism frost heaving mechanism includes:
(1) the cushion layer adopts coarse-grained soil, so that water absorption is difficult and water drainage is easy. Certain drainage buffer time is reserved for the soil layer below the cushion layer;
(2) the thermal physical parameter parameters of the coarse-grained soil change along with the change of the water content and the density, and the freezing depth is influenced to a certain extent;
(3) when the moisture environments are the same, the water holding capacity of coarse-grained soil is lower than that of the original foundation, so that the freezing force between the soil plates is reduced after freezing, and the concrete is convenient to pour.
(4) When the coarse soil and the fine soil are filled in layers, the coarse soil and the fine soil have certain functions of resisting hair and reducing seepage, and the influence of underground water is weakened.
b. The steel bars are checked, bound and installed, the steel bars are bound and installed by adopting double-layer bidirectional configuration, the anti-cracking structural steel bars are arranged by adopting stress and structural steel bars in a through manner, the reinforcement ratio of the temperature and the shrinkage steel bars is not less than 0.10%, and the spacing is not more than 180 mm; when the concrete surface layer is not allowed to crack, reinforcing steel bar meshes with the diameter of 4mm and the distance of 100mm are arranged at the position 20mm away from the top surface of the concrete; reinforcing steel bars with phi 8-14mm and a spacing of 100-150mm are adopted to increase and match structural ribs, and the reinforcement ratio of the whole section is not less than 0.3 percent
c. Installing a concrete template, and splicing and supporting the template by using a steel plate net, a die-removal-free wire netting or a small wood board; the method is characterized in that sundries such as garbage, mud and the like in the template and oil stains on the steel bars are removed completely, and the cushion blocks of the steel bars are well cushioned, if a wood template is used, the template is watered to be wet, but no ponding is left on a base layer.
d. Selecting concrete raw materials, namely cement, aggregate and sand; the raw material is low-heat slag portland cement; selecting aggregates, namely selecting non-alkali active aggregates; the fine aggregate is medium sand, the content of particles passing through a sieve pore of 0.315mm is not less than 15%, the aggregate with large elastic modulus is adopted, the coarse aggregate is 6-30 mm in particle size, continuous grading is adopted, the content of needle piece particles is not more than 10%, and the content of mud is not more than 1%.
e. Optimizing the mixing proportion of concrete, wherein the water cement ratio of the concrete is 0.4-0.6, the sand rate is 39-45%, and the slump is 12-16 cm;
(1) in order to reduce absolute water consumption and cement consumption, improve concrete workability and pumpability and prolong delayed coagulation time, high-quality fly ash and anti-cracking, anti-seepage, water-reducing and delayed coagulation additives are added.
(2) In order to compensate the shrinkage of the concrete, a certain amount of expanding agent is blended.
(3) The raw material is low-heat slag portland cement; selecting aggregates, namely selecting non-alkali active aggregates; the fine aggregate is medium sand, the content of particles passing through a sieve pore of 0.315mm is not less than 15%, the aggregate with large elastic modulus is adopted, the coarse aggregate is 6-30 mm in particle size, continuous gradation is adopted, the content of needle piece particles is not more than 10%, and the content of mud is not more than 1%.
f. Hydration heat test, measuring the heat productivity of 3 days, 7 days, 14 days and 28 days, wherein the hydration heat of 7 days is not more than 250 kj/kg; the cement hydration calorific value of the large-volume concrete is the most critical parameter for controlling the temperature cracks, therefore, hydration heat experimental research must be carried out simultaneously when a mix proportion experiment is carried out, errors caused by calculation of concrete hydration heat by hydrothermal reaction of a cementing material can be avoided, the experimental precision is improved, the pouring integrity of the concrete is ensured, and cracking is prevented.
g. Performing on-site over-examination;
h. examining, approving and pouring and vibrating, wherein the vibrating time of each point is 15-30 s, and secondary re-vibration is carried out after 20-25 min, and the concrete steps are as follows:
(1) the operation of the vibrating rod needs to realize 'fast insertion and slow pulling'. In the vibrating process, the vibrating rod is preferably slightly drawn up and down so as to be uniformly vibrated up and down;
(2) the vibration time of each insertion point needs to be controlled well, the concrete is difficult to tamp due to too short vibration time, the concrete can be separated due to too long vibration time, the vibration time of each insertion point is generally controlled to be 15-30 s, and secondary re-vibration is carried out after 20-25 min. When concrete is poured, a section of concrete is vibrated and then spread by a shovel and tamped;
(3) the distance between the vibrating rods is set to be about 400mm, corresponding technical measures are pre-made particularly for the reserved holes, embedded parts and the dense parts of the reinforcing steel bars, and smooth material distribution and dense vibration are guaranteed.
i. Temperature measurement maintenance, starting temperature measurement after concrete enters a mold, measuring temperature for 1 time every 2 hours, recording and calculating a lifting value and a temperature difference value of each temperature measurement point, feeding data back to a construction unit and a supervision unit in time, immediately checking whether a temperature measurement instrument has a fault when the temperature difference between the inside and the outside of concrete exceeds 22 ℃, and informing site construction management personnel and related personnel to take corresponding measures when the temperature difference exceeds 25 ℃:
(1) remedying the concrete which is not cured in place; the heat preservation is strengthened in time or the removal of heat preservation materials is slowed down, thereby preventing the concrete from generating temperature difference stress cracks.
(2) The surface temperature of the concrete is increased or the number of layers of the grass covering layer is increased by adopting a manual method, so that the cracking of the concrete caused by temperature difference stress is avoided.
Prevention measures for temperature stress cracking:
the large-volume concrete can generate a large amount of hydration heat in the hydration and solidification process, and because the heat dissipation of the surface and the side of the concrete is fast, and the heat dissipation of the interior is slow, a large temperature difference is formed between the center and the surface of the concrete, and if no proper measures are taken, the temperature stress is generated in the concrete to cause the concrete to crack.
When the concrete is formed, because the cement slurry on the surface of the concrete is thick, a long scraping rule is selected for scraping, then a wood trowel is used for trowelling, after the concrete is initially set, the trowel is used for trowelling and pressing once, and the surface cracks of the concrete are reduced. Covering immediately after the concrete is vibrated, and preferably adopting a plastic film for closed maintenance to prevent the concrete from being dehydrated and cracked. The covered heat insulating material can effectively control the temperature difference between the inside and the surface of the concrete and the temperature difference between the surface of the concrete and the atmosphere, thereby preventing the concrete from generating cracks due to temperature difference stress. If necessary, a layer of plastic color strip cloth is covered on the straw bag, so that the heat preservation and moisture preservation effects are better.
And (3) heat preservation and moisture preservation maintenance of concrete:
spraying a health-care solution with good film-forming property at low temperature by using an agricultural sprayer within 12h after the concrete is poured, covering two layers of straw bags with proper wet water, and staggering the straw bags up and down, overlapping and pressing; spraying health preserving liquid is adopted for the peripheral side of the bottom plate, grass bags are staggered up and down, are in lap joint and are compressed, the spraying health preserving liquid is also adopted for the peripheral side of the bottom plate, heat preservation and maintenance can reduce heat diffusion on the surface of concrete, temperature difference on the surface of the concrete is reduced, surface cracks are prevented, and moisture preservation and maintenance can prevent the surface of the concrete from being dehydrated and generating surface shrinkage cracks.
In the curing process, the surface of the concrete may be whitened in advance due to the addition of the additive, water is needed for curing, the concrete should be watered at around noon in fine day in winter, the concrete should be watered immediately in other seasons, and the heat insulation material is lifted and covered, which is important to pay attention.
Dismantling the heat insulation material:
the temperature difference between the inside and the surface of the concrete and the temperature difference between the surface and the atmosphere are less than 25 ℃. After the concrete is poured, the temperature is raised in the peak in the third and fourth days, then the temperature is gradually lowered, and the heat-insulating material is removed for more than 10 days. The dismantling cannot be completed at one time, and the dismantling must be gradually carried out in batches on the basis of real-time monitoring. The cooling speed should not be too fast to prevent the temperature difference stress from generating cracks. Especially, the change of weather, especially the enhancement of heat preservation before the cold tide comes, is noticed.
Concrete bleeding treatment:
the concrete is poured in a blocking and layering mode, the concrete pouring intermittent time is long (generally 1.5-3 h is controlled before initial setting), and a water draining layer is easy to generate.
The solution of bleeding is as follows: set up 1% slope when the concrete is leveled and will secrete the water and discharge into the ditch nearby in, concentrate unnecessary water and take away through the sump pit with the diaphragm pump, forbid the concrete and water in the aquatic and smash, avoid producing honeycomb, gas pocket because of the water logging soaks the concrete, it is not closely knit.
And (4) personnel maintenance:
on a day-and-night duty basis, the following people are: each technician is one for each class, and the maintainers arrange according to the workload.
The concrete is poured to be subjected to inclined surface layering, and the layered pouring thickness of the concrete is estimated according to the concrete slump and the pouring amount in the initial setting time of the concrete, as shown in the attached figure 1 of the specification.
The real-time scene is specifically as follows: when the pouring area is too large and too long, performing slump test, obtaining concrete slump according to the test result, simultaneously obtaining the initial setting time of concrete, dividing large-area laying into two sections for slope layering, then laying, and simultaneously carrying out from the middle to two ends or from two ends to the middle, wherein when pouring is carried out, the concrete pouring gap time between different pouring areas and between an upper layer and a lower layer does not exceed the initial setting time of concrete, and the control of laying thickness is carried out according to the slump.
And (3) environmental protection measures:
(1) the concrete material, especially the admixture, meets the requirement of environmental protection;
(2) in the concrete transportation and pumping process, the concrete is not thrown, and the surplus and a small amount of concrete are reasonably utilized;
(3) in the concrete construction process, protective measures such as noise reduction and noise reduction are adopted, and the construction time is staggered with the rest time of nearby residents;
(4) the building wastewater is firstly precipitated and discharged into a domestic wastewater discharge pipeline, and if required, the building wastewater is recycled.
The application process of the embodiment of the invention is as follows: the concrete is poured in a whole structural plane in a layering mode comprehensively, and when the first layer is poured back to pour the second layer after being poured, the concrete poured by the first layer is not initially set, the concrete is poured layer by layer until the pouring is finished, the concrete is constructed along the short edge and along the long edge, two sections are needed to be simultaneously poured from the middle to two ends or two ends to the middle, the pouring thickness is not more than 50CM, the concrete is not prone to crack after maintenance and observation are carried out, the shrinkage of the concrete is low, the ultimate tensile capacity of the concrete is high, the frost resistance of a base surface is enhanced, the expansibility is reduced, and therefore the concrete ground which is prone to crack and collapse after the concrete is poured is reduced.
Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
In the present specification, the terms "upper", "lower", "left", "right", "middle", and the like are used for clarity of description, and are not intended to limit the scope of the present invention, and changes or modifications in the relative relationship may be made without substantial changes in the technical content.
Claims (10)
1. The seamless construction process of the concrete floor with the ultra-large area comprises cement, sand, stones, concrete additives and fly ash, and is characterized in that: not staying in the seamless construction of concrete ground and establishing expansion joint and post-cast strip, the concrete is pour in whole structural plane in the layering comprehensively, and when guaranteeing to return after the first layer is poured and pour the second floor, the concrete that the first layer was pour has not just set, so the successive layer goes on, until pouring the end, start along the minor face during the construction, go on along long limit, also divide two sections as necessary, go on to both ends or both ends to the centre simultaneously from the centre, pour thickness and be no more than 50CM, specifically include following step:
a. performing cushion layer treatment, namely directly pouring and flattening concrete, wherein the thickness of a cushion layer of the extended foundation is not less than 70mm, and the strength grade of the cushion layer concrete is not less than C10;
b. the steel bar is checked, bound and installed, the steel bar binding installation adopts double-layer bidirectional configuration, the anti-cracking structural steel bar adopts stress and structural steel bar through arrangement, the temperature and shrinkage steel bar reinforcement ratio is not less than 0.10%, and the spacing is not more than 180 mm;
c. installing a concrete template, and splicing and supporting the template by using a steel plate net, a die-removal-free wire netting or a small wood board;
d. selecting concrete raw materials, namely cement, aggregate and sand;
e. optimizing the mixing proportion of concrete, wherein the water cement ratio of the concrete is 0.4-0.6, the sand rate is 39-45%, and the slump is 12-16 cm;
f. hydration heat test, measuring the heat productivity of 3 days, 7 days, 14 days and 28 days, wherein the hydration heat of 7 days is not more than 250 kj/kg;
g. performing on-site over-examination;
h. approving pouring and vibrating, wherein the vibrating time of each point is 15-30 s, and secondary re-vibration is carried out after 20-25 min;
i. and (3) temperature measurement and maintenance, wherein the temperature measurement is started when the concrete is poured into a mold, the temperature is measured for 1 time every 2 hours, the rising and falling value and the temperature difference value of each temperature measurement point are recorded and calculated, data are fed back to a construction unit and a supervision unit in time, when the temperature difference between the inside and the outside of the concrete exceeds 22 ℃, whether a temperature measurement instrument fails or not is immediately checked, and when the temperature difference exceeds 25 ℃, field construction managers and related personnel are informed to take corresponding measures.
2. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: the cushion course treatment comprises the steps of adopting coarse-grained soil and reserving certain water changing buffer time for a soil layer below the cushion course.
3. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: the raw material of the concrete is low-heat slag portland cement; selecting aggregates, namely selecting non-alkali active aggregates; the fine aggregate is medium sand, the content of particles passing through a sieve pore of 0.315mm is not less than 15%, the aggregate with large elastic modulus is adopted, the coarse aggregate is 6-30 mm in particle size, continuous gradation is adopted, the content of needle piece particles is not more than 10%, and the content of mud is not more than 1%.
4. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: the concrete is doped with high-quality fly ash and additives for crack resistance, seepage prevention, water reduction, retardation and the like during the preparation.
5. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: when the concrete formwork is installed, sundries such as garbage and soil in the formwork and oil stains on the steel bars are removed completely, and the cushion blocks of the steel bars are well cushioned.
6. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: when concrete is poured, the pouring clearance time of the concrete between different pouring areas and between an upper layer and a lower layer is not more than the initial setting time of the concrete.
7. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: after a certain amount of mass concrete is poured according to a reference elevation surface, before the concrete is initially set, the surface of the mass concrete is stricken off by using an aluminum alloy long scraping rule, the mass concrete is stricken off by using wooden crabs, the mass concrete is firstly wielded off, after water is collected, secondary plastering is carried out, water collecting cracks appear on the surface along the positions of reinforcing steel bars, the mass concrete is rolled for a plurality of times by using a roller, the mass concrete is kneaded by using the wooden crabs, and the water collecting cracks are closed.
8. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: in the process of vibrating the concrete, the vibrating rod is slightly pulled up and down to vibrate uniformly up and down by 'inserting and pulling slowly'.
9. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: and curing the concrete after pouring, watering for curing, watering at noon in fine weather in winter, immediately watering in other seasons, lifting the heat-insulating material to cover, removing the heat-insulating material for more than 10 days, gradually removing the heat-insulating material in batches in stages on the basis of real-time monitoring, slowing down the cooling speed, paying attention to weather changes, and enhancing heat preservation before cold tides.
10. The seamless construction process for the concrete floor with the ultra-large area as recited in claim 1, characterized in that: in the maintenance stage, the personnel have the following according to the day and night duty consideration: each technician is one for each class, and the maintainers arrange according to the workload.
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