concretestructureThe quality of the project is an important issue affecting the safety and durability of the structure.There are many reasons for quality problems. Now let's talk about common quality problems and defect repair.
Concrete construction quality and defect repair - Figure 1
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How to control the construction quality of concrete works?First, control the quality of raw materials.Secondly, scientific preparation of concrete is a prerequisite to ensure quality.3、 Do a good job of the site laboratory.4、 The concrete specimens are qualified, but not all the concrete of structures are qualified.5、 Workability is the main factor determining the quality of concrete.6、 The concrete pouring and vibrating process is the main link of concrete quality.Finally, it is emphasized that in order to ensure the quality of concrete, people's quality awareness is also very important;At the same time, the design unit, the supervision unit and the construction unit work together to ensure the quality of concrete.
Code for Acceptance of Construction Quality of Concrete Structures GB502042015 Implemented by the Ministry of Housing and Urban Rural Development on September 1, 2015
The scheme is reasonably arranged, with complete chapters, rich content, complete format, neat and beautiful content layout, smooth sentences, smooth expression of the full text, and can be used directly
The total construction area is 54316.07 ㎡ (a first-class passenger station), and the land area is 40570 ㎡.The building has three floors on the ground and two floors underground. The height of the highest point of the building is 24.290m. The building structure is a frame structure. The thickness of the basement retaining wall is 300-600mm. The frame column is a cylinder with a diameter of 600. The concrete volume is about 100000 m3, including about 12000 m3 of C60 high-strength concrete, which is all constructed with pumped commercial concrete.Due to the need of the construction period, the project will be constructed in winter, and because Harbin is in a cold region and the temperature is low in winter, with the consent of the design institute, the wall and column concrete grades will be increased by two grades, while the construction quality of C60 high-strength concrete is difficult to control. How to ensure that the construction quality of the concrete subdivisional works reaches the "Longjiang Cup" standard has become the key to whether the goal of creating excellence of the project can be achieved.
With the development of economic society and the continuous improvement of the level of the construction industry, people pay more and more attention to the appearance quality of concrete.But at present, the theory and practical experience of concrete appearance quality control in our country are less, so the control of concrete appearance quality has become an important technical topic that engineering technicians need to study and explore.
According to the field measurement results of Golden Garden Section II and the requirements of the completed concrete appearance quality inspection, the appearance quality defects of the project are analyzed in detail and the prevention and treatment plan is formulated
In order to ensure the quality of concrete structure appearance and make up for the general defects of concrete structure appearance.The repair plan is hereby prepared according to the actual situation of the site and the concrete appearance defects and repair experience that often occur in the past construction process, and please submit it to the supervision team for review.
With the notice of the State Council on further promoting the innovation of wall materials and prohibiting the use of clay bricks in Suzhou, autoclaved aerated concrete blocks have gradually become the main materials of engineering construction walls. How to control the construction quality of autoclaved aerated concrete blocks and reduce the common quality problems of masonry projects has become the key in construction.At present, the most common problems in the construction of autoclaved aerated concrete blocks are: common problems such as cracks, hollowing, leakage and cracks in mortar joints on the plastering surface. How to reduce the construction quality problems of autoclaved aerated concrete blocks, I summarized the following aspects from the actual construction, hoping to be useful to peers:
Introduction: The author of this article, through his own construction practice and summary, comprehensively expounds some common quality problems and defects in the current concrete construction, analyzes and lists the main causes of these common quality problems, and accordingly puts forward some operable preventive measures and links that should be focused on control during construction. In addition,This article also briefly introduces some remedies for defects, which can be used for reference by peers
The completion of the project will solve the problem of sewage treatment of nearly 500000 square kilometers in Hedong, * * * City, effectively improve the water quality of several waterworks in the city, and reduce the pollution of the lower reaches of the Xiangjiang River.
Project name: Zhejiang Film and Television Post production Center Phase I Film and Television Post production Complex Building ProjectBuilding area Total building area: 190243 square meters;The aboveground building area is 142830 square meters, and the underground building area is 47413 square metersBuilding scale and height The height of the main building (42F) is 218m, and the height of the podium building (5F) is 30mThe main structure is frame core tube structure;Frame shear wall structure of podium in studio area;Frame structure of the podium on the north side of the main buildingThe number of floors is 2 floors underground, and the above ground part is composed of a 5-storey podium and a 42 storey tower.The quality requirements ensure the "Qianjiang Cup" and strive for the "Luban Prize".The volume of wall masonry is about 19000 ㎡. 200 thick autoclaved sand aerated concrete block walls are used for some exterior walls above ± 0.00 elevation, 200 or 100 thick autoclaved sand aerated concrete block walls are used for interior walls, and 200 thick autoclaved sand aerated concrete block walls are used for firewalls. The fire resistance limit is more than 3 hours, and special adhesives are used for masonry.Considering the influence of the quality of autoclaved aerated concrete block masonry on the later wall plastering, the Project Department requires strict control of the construction quality of aerated concrete blocks to ensure the smooth progress of later plastering.However, in the process of aerated block masonry, it is easy to see the deviation of the flatness and perpendicularity of the masonry, the uneven mortar leakage during the pouring of the ring beam structural column, and the weak quality awareness of workers.
Snap the horizontal control line according to the elevation: measure the cushion elevation downward according to the+50cm horizontal elevation line on the wall, and snap it on the surrounding walls if possible.
In today's building field, reinforced concrete structure has become the main form of building structure.In particular, high-rise buildings, super high-rise buildings, special structures and large equipment foundations all adopt massive concrete structures.
Abstract: This paper introduces the cause analysis of the appearance quality defects of concrete structures and the control measures for the appearance quality of concrete, which can be used as a reference for engineers and technicians
Cause of quality defect accident Violation of basic construction procedure Engineering geological survey error or foundation treatment error Design problems during construction Natural conditions affect improper use of buildings
The determination of quality defects of concrete structures has always puzzled the majority of concrete practitioners.Because of the working relationship, I moved from the laboratory to the front line, and did a lot of work in concrete technical services and structural quality defect identification. I handled and identified hundreds of cases on the site, with some understanding.Coincidentally, a student who had listened to my class sent me a WeChat message a few days ago, asking me to help identify how the defect came into being, how to avoid it, how to deal with it, and so on. I told him a lot, and I felt a lot, so I decided to write this insight.
1. Purpose The purpose of defect repair is to: (1) ensure the appearance quality of the concrete, ensure that the surface is flat, free of dislocation, concave and convex, the concrete is dense, free of holes, honeycombs and pits, the shape is complete, neat and beautiful, free of pollution, color difference, etc;(2) Ensure the safety of railway operation.2. The scope of application is applicable to the repair of tunnel concrete appearance quality defects and the treatment of structural quality defects.
This document is about the quality, defects and accidents in concrete engineering. It is in PPTF format and has 75 pages in total. There are four common causes of defects in concrete engineering: 1. Defects and cracks caused by improper material selection; 2. Defects and cracks caused by construction violation of operating procedures; 3. Cracks caused by component stress and deformation; 4. Defects and cracks caused by environmental factors
The special plan for concrete repair can be used in large public construction projects and residential projects. It summarizes the solutions to most common problems of concrete quality
The appearance quality of concrete is the intuitive embodiment of concrete quality, so it is of great significance to improve the appearance quality of concrete for concrete engineering.According to many problems existing in the appearance quality of the concrete on the project site, the Project Department, through practical exploration and summary analysis, has formulated the following repair scheme to effectively control the appearance quality of the concrete.
The common quality problems in the construction of hybrid structures are 1Low quality of bricks or stones;The strength of masonry mortar is less than 2The masonry method does not meet the requirements 3Mortar plumpness difference 4Measurement and setting out error, etc
With the rapid development of China's construction industry, especially the development of high-rise buildings, underwater concrete cast-in-place piles are widely used in construction projects, so improving the construction quality of underwater concrete cast-in-place piles is a problem worth discussing.In this paper, many aspects of the construction process are described, and strive to improve the construction quality of underwater concrete cast-in-place piles.
1.0.1 This specification is formulated to strengthen the quality management of building works, unify the acceptance of construction quality of concrete structure works, and ensure the project quality.1.0.2 This specification is applicable to the acceptance of the construction quality of concrete structures in building engineering, not to the acceptance of the construction quality of special concrete structures.1.0.3 The requirements for construction quality in the contract and engineering technical documents of concrete structure engineering shall not be lower than the provisions of this specification.1.0.4 This specification shall be used together with the national standard Unified Standard for Construction Quality Acceptance of Building Engineering (GB 50300-2001).1.0.5 The acceptance of the construction quality of concrete structure engineering shall not only comply with this specification, but also comply with the provisions of the current national standards.
This paper analyzes on the causes of the common quality problems of cast-in-place concrete structure, such as cracks, honeycombs and pits, exposed reinforcement, strength deviation, surface unevenness, concrete sandwich and external dimension deviation, and puts forward corresponding preventive measures and treatment methods.