Construction scheme of the hottest concrete struct

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Construction scheme of concrete structure works

before concrete construction, the concealed works shall be accepted together with relevant departments, and the concrete construction can be carried out only after it fully meets the requirements of the design and specifications

no construction joints shall be left in the construction of foundation concrete to ensure that each layer of concrete is covered by the previous layer of concrete before the initial setting. Before pouring and tamping the wallboard concrete, cement mortar shall be used for grouting. During the construction, two aspects shall be achieved: Labor Organization and sufficient preparation of materials and materials; Three reliability, namely, the scaffold platform, machinery and equipment, and technical measures are reliable; The four unimpeded ways are dispatching and commanding, pouring and tamping, electrical water supply lines and on-site roads, so as to ensure the smooth pouring and tamping of concrete and prevent accidental cold joints

the vibration adopts the plug-in vibrator, and the personnel are divided into three shifts. The supporting personnel shall make a detailed list before the concrete pouring and tamping, and implement it to each person. During vibration, the insertion depth and vibration time of the vibrator shall be strictly controlled, and the construction method of "fast insertion and slow extraction" shall be adopted. It is strictly forbidden to make the concrete dense by vibrating the reinforcement. When pouring and tamping the foundation, it is poured and tamped from the middle to both sides to ensure the connection between the new and old teams

the project foundation is a strip foundation, and appropriate measures should be taken during construction to ensure the quality of concrete construction

first of all, the concrete mix proportion should be properly selected. On the one hand, measures such as using cement with low hydration heat and adding high-quality fly ash should be taken to reduce the cement mud and cement hydration heat as soon as possible; On the other hand, a certain amount of micro expansion agent is added to the mass concrete to form a partially shrinkage compensating concrete, which reduces the shrinkage cracks in the ancient hardening process of the concrete. At the same time, because it replaces part of the cement, it also reduces the hydration heat and further reduces the internal temperature difference

when pouring and tamping concrete, the layered pouring method is adopted. On the one hand, even if the deflection tensile coefficient D is confirmed during construction, the internal heat of the concrete can be effectively dissipated. On the other hand, the vibration is strengthened to improve the compactness of the concrete, so that it has a relatively strong crack resistance

using information construction is a key measure to prevent cracks in mass concrete. In order to timely understand and control the temperature rise of concrete, temperature measuring equipment shall be embedded in advance before pouring and tamping concrete. It is considered to arrange two temperature measuring points on the bottom plate, one in the middle of the concrete and one on the surface. The sensor for measuring the intermediate temperature is embedded in the component during concrete pouring. Temperature measuring points on the surface of components Φ 25 100mm deep round hole and pour water. The specific location depends on the site conditions. Use JDC-2 electronic thermometer to measure temperature. In the process of concrete pouring and tamping, the internal and external temperature difference of concrete shall be detected at any time, and measures such as covering straw bags and plastic films shall be taken to reduce the internal and external temperature difference of concrete; It shall be measured every 4H within three days after pouring, and then every 8h. At the same time, the atmospheric temperature shall be measured for a total of 7 days. Strictly control the temperature difference of concrete to not exceed 25 ℃ required by the specification

(I) requirements for concrete:

see the general plan for the erection position of the foundation concrete mixer of the project. The partition wall of the gravel yard is built with bricks, and the concrete waist hoop and coping are added

a. concrete slump: controlled at 3~5cm, and adjusted appropriately with the season

b, concrete mix proportion: apply to the laboratory for grading test in advance, and the laboratory will provide the concrete grading sheet. Before concrete construction, the construction mix proportion should be adjusted according to the actual moisture content of the aggregate on site. With the approval of the supervisor, the formation of the construction mix proportion will provide you with a detailed method to solve the problem of the deviation of the test value of the tensile testing machine, and weigh it strictly according to the construction mix proportion

c, cement requirements: cement must be of good quality, and there must be a quality warranty when entering the site. It must be inspected according to the variety, grade, date of delivery, etc., and its strength, stability, and other necessary indicators should be re inspected. Its quality must meet the provisions of the current national standard Portland cement, ordinary portland cement GB175, etc. When "he Minghui said that he has doubts about the quality of cement in use or the cement has been out of the factory for more than three months (fast hardening portland cement for more than one month), it should be re inspected and used according to the re inspection results

d. aggregate requirements: aggregates with suitable origin and good quality must be selected. Retesting must be carried out in time according to the inspection requirements when entering the site, and they must be stacked separately according to the variety and specification

(II) requirements for the production of concrete test blocks:

① no less than one sample of the same proportion of concrete mixed with 100 plates and no more than 100m3

② when the concrete with the same mix proportion mixed by each working shift is less than 100 plates, the sampling shall not be less than once

③ the concrete of the same proportion on each floor shall be sampled at least once

④ at least one group of standard curing specimens shall be retained for each sampling, and the number of retention groups of curing specimens under the same conditions shall be determined according to the actual needs. And the formwork removal test pieces shall be properly reserved according to the construction needs

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